diff --git a/.github/workflows/assemble.yml b/.github/workflows/assemble.yml
index 6a66ac5fb5609..87cecdf38c072 100644
--- a/.github/workflows/assemble.yml
+++ b/.github/workflows/assemble.yml
@@ -7,13 +7,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
+        java: [ 11, 17, 21 ]
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 11
+      - name: Set up JDK ${{ matrix.java }}
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: ${{ matrix.java }}
           distribution: temurin
       - name: Setup docker (missing on MacOS)
         if: runner.os == 'macos'
diff --git a/.github/workflows/precommit.yml b/.github/workflows/precommit.yml
index b04f404b11c55..cd75eb47946a4 100644
--- a/.github/workflows/precommit.yml
+++ b/.github/workflows/precommit.yml
@@ -7,13 +7,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
+        java: [ 11, 17, 21 ]
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 11
+      - name: Set up JDK ${{ matrix.java }}
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: ${{ matrix.java }}
           distribution: temurin
           cache: gradle
       - name: Run Gradle (precommit)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 601934fde849e..fc797f6144d41 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Remote cluster state] Restore global metadata from remote store when local state is lost after quorum loss ([#10404](https://github.com/opensearch-project/OpenSearch/pull/10404))
 - [AdmissionControl] Added changes for AdmissionControl Interceptor and AdmissionControlService for RateLimiting ([#9286](https://github.com/opensearch-project/OpenSearch/pull/9286))
 - GHA to verify checklist items completion in PR descriptions ([#10800](https://github.com/opensearch-project/OpenSearch/pull/10800))
+- [Remote cluster state] Restore cluster state version during remote state auto restore ([#10853](https://github.com/opensearch-project/OpenSearch/pull/10853))
 
 ### Dependencies
 - Bump `log4j-core` from 2.18.0 to 2.19.0
@@ -95,10 +96,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Remote Store] Add repository stats for remote store([#10567](https://github.com/opensearch-project/OpenSearch/pull/10567))
 - Add search query categorizer ([#10255](https://github.com/opensearch-project/OpenSearch/pull/10255))
 - Introduce ConcurrentQueryProfiler to profile query using concurrent segment search path and support concurrency during rewrite and create weight ([10352](https://github.com/opensearch-project/OpenSearch/pull/10352))
+- Update the indexRandom function to create more segments for concurrent search tests ([10247](https://github.com/opensearch-project/OpenSearch/pull/10247))
 - [Remote cluster state] Make index and global metadata upload timeout dynamic cluster settings ([#10814](https://github.com/opensearch-project/OpenSearch/pull/10814))
-- Added cluster setting cluster.restrict.index.replication_type to restrict setting of index setting replication type ([#10866](https://github.com/opensearch-project/OpenSearch/pull/10866))
 - Add cluster state stats ([#10670](https://github.com/opensearch-project/OpenSearch/pull/10670))
 - [Tiered caching] Enabling serialization for IndicesRequestCache key object ([#10275](https://github.com/opensearch-project/OpenSearch/pull/10275))
+- Adding slf4j license header to LoggerMessageFormat.java ([#11069](https://github.com/opensearch-project/OpenSearch/pull/11069))
+- [Streaming Indexing] Introduce new experimental server HTTP transport based on Netty 4 and Project Reactor (Reactor Netty) ([#9672](https://github.com/opensearch-project/OpenSearch/pull/9672))
 
 ### Dependencies
 - Bump `com.google.api.grpc:proto-google-common-protos` from 2.10.0 to 2.25.1 ([#10208](https://github.com/opensearch-project/OpenSearch/pull/10208), [#10298](https://github.com/opensearch-project/OpenSearch/pull/10298))
@@ -111,26 +114,33 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Bump `org.codehaus.woodstox:stax2-api` from 4.2.1 to 4.2.2 ([#10639](https://github.com/opensearch-project/OpenSearch/pull/10639))
 - Bump `com.google.http-client:google-http-client` from 1.43.2 to 1.43.3 ([#10635](https://github.com/opensearch-project/OpenSearch/pull/10635))
 - Bump `com.squareup.okio:okio` from 3.5.0 to 3.6.0 ([#10637](https://github.com/opensearch-project/OpenSearch/pull/10637))
-- Bump `org.apache.logging.log4j:log4j-core` from 2.20.0 to 2.21.0 ([#10858](https://github.com/opensearch-project/OpenSearch/pull/10858))
+- Bump `org.apache.logging.log4j:log4j-core` from 2.20.0 to 2.21.1 ([#10858](https://github.com/opensearch-project/OpenSearch/pull/10858), [#11000](https://github.com/opensearch-project/OpenSearch/pull/11000))
 
 ### Changed
 - Mute the query profile IT with concurrent execution ([#9840](https://github.com/opensearch-project/OpenSearch/pull/9840))
 - Force merge with `only_expunge_deletes` honors max segment size ([#10036](https://github.com/opensearch-project/OpenSearch/pull/10036))
 - Add the means to extract the contextual properties from HttpChannel, TcpCChannel and TrasportChannel without excessive typecasting ([#10562](https://github.com/opensearch-project/OpenSearch/pull/10562))
+- Search pipelines now support asynchronous request and response processors to avoid blocking on a transport thread ([#10598](https://github.com/opensearch-project/OpenSearch/pull/10598))
 - [Remote Store] Add Remote Store backpressure rejection stats to `_nodes/stats` ([#10524](https://github.com/opensearch-project/OpenSearch/pull/10524))
 - [BUG] Fix java.lang.SecurityException in repository-gcs plugin ([#10642](https://github.com/opensearch-project/OpenSearch/pull/10642))
 - Add telemetry tracer/metric enable flag and integ test. ([#10395](https://github.com/opensearch-project/OpenSearch/pull/10395))
 - Add instrumentation for indexing in transport bulk action and transport shard bulk action. ([#10273](https://github.com/opensearch-project/OpenSearch/pull/10273))
+- [BUG] Disable sort optimization for HALF_FLOAT ([#10999](https://github.com/opensearch-project/OpenSearch/pull/10999))
+- Performance improvement for MultiTerm Queries on Keyword fields ([#7057](https://github.com/opensearch-project/OpenSearch/issues/7057))
+- Disable concurrent aggs for Diversified Sampler and Sampler aggs ([#11087](https://github.com/opensearch-project/OpenSearch/issues/11087))
 
 ### Deprecated
 
 ### Removed
+- Remove deprecated classes for Rounding ([#10956](https://github.com/opensearch-project/OpenSearch/issues/10956))
 
 ### Fixed
 - Fix failure in dissect ingest processor parsing empty brackets ([#9225](https://github.com/opensearch-project/OpenSearch/pull/9255))
 - Fix class_cast_exception when passing int to _version and other metadata fields in ingest simulate API ([#10101](https://github.com/opensearch-project/OpenSearch/pull/10101))
 - Fix Segment Replication ShardLockObtainFailedException bug during index corruption ([10370](https://github.com/opensearch-project/OpenSearch/pull/10370))
 - Fix some test methods in SimulatePipelineRequestParsingTests never run and fix test failure ([#10496](https://github.com/opensearch-project/OpenSearch/pull/10496))
+- Fix passing wrong parameter when calling newConfigurationException() in DotExpanderProcessor ([#10737](https://github.com/opensearch-project/OpenSearch/pull/10737))
+- Adding version condition while adding geoshape doc values to the index, to ensure backward compatibility.([#11095](https://github.com/opensearch-project/OpenSearch/pull/11095))
 
 ### Security
 
diff --git a/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java b/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java
deleted file mode 100644
index cdbcbfc163191..0000000000000
--- a/benchmarks/src/main/java/org/opensearch/benchmark/time/RoundingBenchmark.java
+++ /dev/null
@@ -1,180 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.benchmark.time;
-
-import org.opensearch.common.Rounding;
-import org.opensearch.common.rounding.DateTimeUnit;
-import org.opensearch.common.time.DateUtils;
-import org.opensearch.common.unit.TimeValue;
-import org.joda.time.DateTimeZone;
-import org.openjdk.jmh.annotations.Benchmark;
-import org.openjdk.jmh.annotations.BenchmarkMode;
-import org.openjdk.jmh.annotations.Fork;
-import org.openjdk.jmh.annotations.Measurement;
-import org.openjdk.jmh.annotations.Mode;
-import org.openjdk.jmh.annotations.OutputTimeUnit;
-import org.openjdk.jmh.annotations.Scope;
-import org.openjdk.jmh.annotations.State;
-import org.openjdk.jmh.annotations.Warmup;
-
-import java.time.ZoneId;
-import java.time.ZoneOffset;
-import java.util.concurrent.TimeUnit;
-
-import static org.opensearch.common.Rounding.DateTimeUnit.DAY_OF_MONTH;
-import static org.opensearch.common.Rounding.DateTimeUnit.MONTH_OF_YEAR;
-import static org.opensearch.common.Rounding.DateTimeUnit.QUARTER_OF_YEAR;
-import static org.opensearch.common.Rounding.DateTimeUnit.YEAR_OF_CENTURY;
-
-@Fork(3)
-@Warmup(iterations = 10)
-@Measurement(iterations = 10)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(TimeUnit.NANOSECONDS)
-@State(Scope.Benchmark)
-@SuppressWarnings("unused") // invoked by benchmarking framework
-public class RoundingBenchmark {
-
-    private final ZoneId zoneId = ZoneId.of("Europe/Amsterdam");
-    private final DateTimeZone timeZone = DateUtils.zoneIdToDateTimeZone(zoneId);
-
-    private long timestamp = 1548879021354L;
-
-    private final org.opensearch.common.rounding.Rounding jodaRounding = org.opensearch.common.rounding.Rounding.builder(
-        DateTimeUnit.HOUR_OF_DAY
-    ).timeZone(timeZone).build();
-    private final Rounding javaRounding = Rounding.builder(Rounding.DateTimeUnit.HOUR_OF_DAY).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitJoda() {
-        return jodaRounding.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitJava() {
-        return javaRounding.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding jodaDayOfMonthRounding = org.opensearch.common.rounding.Rounding.builder(
-        DateTimeUnit.DAY_OF_MONTH
-    ).timeZone(timeZone).build();
-    private final Rounding javaDayOfMonthRounding = Rounding.builder(DAY_OF_MONTH).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitDayOfMonthJoda() {
-        return jodaDayOfMonthRounding.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeRoundingDateTimeUnitDayOfMonthJava() {
-        return javaDayOfMonthRounding.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeIntervalRoundingJoda = org.opensearch.common.rounding.Rounding.builder(
-        TimeValue.timeValueMinutes(60)
-    ).timeZone(timeZone).build();
-    private final Rounding timeIntervalRoundingJava = Rounding.builder(TimeValue.timeValueMinutes(60)).timeZone(zoneId).build();
-
-    @Benchmark
-    public long timeIntervalRoundingJava() {
-        return timeIntervalRoundingJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeIntervalRoundingJoda() {
-        return timeIntervalRoundingJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcDayOfMonthJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.DAY_OF_MONTH)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcDayOfMonthJava = Rounding.builder(DAY_OF_MONTH).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcDayOfMonthJava() {
-        return timeUnitRoundingUtcDayOfMonthJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcDayOfMonthJoda() {
-        return timeUnitRoundingUtcDayOfMonthJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcQuarterOfYearJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.QUARTER)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcQuarterOfYearJava = Rounding.builder(QUARTER_OF_YEAR).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcQuarterOfYearJava() {
-        return timeUnitRoundingUtcQuarterOfYearJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcQuarterOfYearJoda() {
-        return timeUnitRoundingUtcQuarterOfYearJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcMonthOfYearJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.MONTH_OF_YEAR)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcMonthOfYearJava = Rounding.builder(MONTH_OF_YEAR).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcMonthOfYearJava() {
-        return timeUnitRoundingUtcMonthOfYearJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcMonthOfYearJoda() {
-        return timeUnitRoundingUtcMonthOfYearJoda.round(timestamp);
-    }
-
-    private final org.opensearch.common.rounding.Rounding timeUnitRoundingUtcYearOfCenturyJoda = org.opensearch.common.rounding.Rounding
-        .builder(DateTimeUnit.YEAR_OF_CENTURY)
-        .timeZone(DateTimeZone.UTC)
-        .build();
-    private final Rounding timeUnitRoundingUtcYearOfCenturyJava = Rounding.builder(YEAR_OF_CENTURY).timeZone(ZoneOffset.UTC).build();
-
-    @Benchmark
-    public long timeUnitRoundingUtcYearOfCenturyJava() {
-        return timeUnitRoundingUtcYearOfCenturyJava.round(timestamp);
-    }
-
-    @Benchmark
-    public long timeUnitRoundingUtcYearOfCenturyJoda() {
-        return timeUnitRoundingUtcYearOfCenturyJoda.round(timestamp);
-    }
-}
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
index a420c8b63b02c..1ad7e056b6ae6 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/DistroTestPlugin.java
@@ -77,9 +77,9 @@
 import java.util.stream.Stream;
 
 public class DistroTestPlugin implements Plugin<Project> {
-    private static final String SYSTEM_JDK_VERSION = "11.0.20+8";
+    private static final String SYSTEM_JDK_VERSION = "17.0.9+9";
     private static final String SYSTEM_JDK_VENDOR = "adoptium";
-    private static final String GRADLE_JDK_VERSION = "17.0.8+7";
+    private static final String GRADLE_JDK_VERSION = "17.0.9+9";
     private static final String GRADLE_JDK_VENDOR = "adoptium";
 
     // all distributions used by distro tests. this is temporary until tests are per distribution
diff --git a/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle b/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
index 74c88e0961c9c..dca2bce94ea6d 100644
--- a/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
+++ b/buildSrc/src/testKit/thirdPartyAudit/sample_jars/build.gradle
@@ -17,7 +17,7 @@ repositories {
 }
 
 dependencies {
-  implementation "org.apache.logging.log4j:log4j-core:2.21.0"
+  implementation "org.apache.logging.log4j:log4j-core:2.21.1"
 }
 
 ["0.0.1", "0.0.2"].forEach { v ->
diff --git a/buildSrc/version.properties b/buildSrc/version.properties
index 96d398c35851d..f19437979c852 100644
--- a/buildSrc/version.properties
+++ b/buildSrc/version.properties
@@ -2,9 +2,7 @@ opensearch        = 3.0.0
 lucene            = 9.8.0
 
 bundled_jdk_vendor = adoptium
-bundled_jdk = 20.0.2+9
-# See please https://github.com/adoptium/temurin-build/issues/3371
-bundled_jdk_linux_ppc64le = 20+36
+bundled_jdk = 21.0.1+12
 
 # optional dependencies
 spatial4j         = 0.7
@@ -31,6 +29,10 @@ jna               = 5.13.0
 netty             = 4.1.100.Final
 joda              = 2.12.2
 
+# project reactor
+reactor_netty     = 1.1.12
+reactor           = 3.5.11
+
 # client dependencies
 httpclient5       = 5.2.1
 httpcore5         = 5.2.2
diff --git a/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java b/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
index d5c1888e78b5d..b0990560b08ba 100644
--- a/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
+++ b/client/rest-high-level/src/test/java/org/opensearch/client/PitIT.java
@@ -24,7 +24,6 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
@@ -72,7 +71,7 @@ public void testCreateAndDeletePit() throws IOException {
         assertTrue(deletePitResponse.getDeletePitResults().get(0).getPitId().equals(createPitResponse.getId()));
     }
 
-    public void testDeleteAllAndListAllPits() throws IOException, InterruptedException {
+    public void testDeleteAllAndListAllPits() throws Exception {
         CreatePitRequest pitRequest = new CreatePitRequest(new TimeValue(1, TimeUnit.DAYS), true, "index");
         CreatePitResponse pitResponse = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
         CreatePitResponse pitResponse1 = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
@@ -91,11 +90,9 @@ public void testDeleteAllAndListAllPits() throws IOException, InterruptedExcepti
         List<String> pits = getAllPitResponse.getPitInfos().stream().map(r -> r.getPitId()).collect(Collectors.toList());
         assertTrue(pits.contains(pitResponse.getId()));
         assertTrue(pits.contains(pitResponse1.getId()));
-        CountDownLatch countDownLatch = new CountDownLatch(1);
         ActionListener<DeletePitResponse> deletePitListener = new ActionListener<>() {
             @Override
             public void onResponse(DeletePitResponse response) {
-                countDownLatch.countDown();
                 for (DeletePitInfo deletePitInfo : response.getDeletePitResults()) {
                     assertTrue(deletePitInfo.isSuccessful());
                 }
@@ -103,19 +100,20 @@ public void onResponse(DeletePitResponse response) {
 
             @Override
             public void onFailure(Exception e) {
-                countDownLatch.countDown();
                 if (!(e instanceof OpenSearchStatusException)) {
                     throw new AssertionError("Delete all failed");
                 }
             }
         };
         final CreatePitResponse pitResponse3 = execute(pitRequest, highLevelClient()::createPit, highLevelClient()::createPitAsync);
-
+        assertTrue(pitResponse3.getId() != null);
         ActionListener<GetAllPitNodesResponse> getPitsListener = new ActionListener<GetAllPitNodesResponse>() {
             @Override
             public void onResponse(GetAllPitNodesResponse response) {
                 List<String> pits = response.getPitInfos().stream().map(r -> r.getPitId()).collect(Collectors.toList());
                 assertTrue(pits.contains(pitResponse3.getId()));
+                // delete all pits
+                highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
             }
 
             @Override
@@ -126,11 +124,12 @@ public void onFailure(Exception e) {
             }
         };
         highLevelClient().getAllPitsAsync(RequestOptions.DEFAULT, getPitsListener);
-        highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
-        assertTrue(countDownLatch.await(10, TimeUnit.SECONDS));
+
         // validate no pits case
-        getAllPitResponse = highLevelClient().getAllPits(RequestOptions.DEFAULT);
-        assertTrue(getAllPitResponse.getPitInfos().size() == 0);
-        highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
+        assertBusy(() -> {
+            GetAllPitNodesResponse getAllPitResponse1 = highLevelClient().getAllPits(RequestOptions.DEFAULT);
+            assertTrue(getAllPitResponse1.getPitInfos().size() == 0);
+            highLevelClient().deleteAllPitsAsync(RequestOptions.DEFAULT, deletePitListener);
+        });
     }
 }
diff --git a/distribution/src/config/jvm.options b/distribution/src/config/jvm.options
index 952110c6c0289..1a0abcbaf9c88 100644
--- a/distribution/src/config/jvm.options
+++ b/distribution/src/config/jvm.options
@@ -81,7 +81,7 @@ ${error.file}
 
 # JDK 20+ Incubating Vector Module for SIMD optimizations;
 # disabling may reduce performance on vector optimized lucene
-20:--add-modules=jdk.incubator.vector
+20-:--add-modules=jdk.incubator.vector
 
 # HDFS ForkJoinPool.common() support by SecurityManager
 -Djava.util.concurrent.ForkJoinPool.common.threadFactory=org.opensearch.secure_sm.SecuredForkJoinWorkerThreadFactory
diff --git a/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java b/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
index cd75bddd680e5..c7b9bee3cbf4d 100644
--- a/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
+++ b/libs/core/src/main/java/org/opensearch/core/common/logging/LoggerMessageFormat.java
@@ -30,6 +30,13 @@
  * GitHub history for details.
  */
 
+/*
+ * This code is based on code from SFL4J 1.5.11
+ * Copyright (c) 2004-2007 QOS.ch
+ * All rights reserved.
+ * SPDX-License-Identifier: MIT
+ */
+
 package org.opensearch.core.common.logging;
 
 import java.util.HashSet;
diff --git a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
index 86d8ad2968e7f..7316847ac6046 100644
--- a/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
+++ b/modules/geo/src/internalClusterTest/java/org/opensearch/geo/search/aggregations/bucket/AbstractGeoBucketAggregationIntegTest.java
@@ -87,7 +87,7 @@ protected boolean forbidPrivateIndexSettings() {
      */
     protected void prepareGeoShapeIndexForAggregations(final Random random) throws Exception {
         expectedDocsCountForGeoShapes = new HashMap<>();
-        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
+        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
         final List<IndexRequestBuilder> geoshapes = new ArrayList<>();
         assertAcked(prepareCreate(GEO_SHAPE_INDEX_NAME).setSettings(settings).setMapping(GEO_SHAPE_FIELD_NAME, "type" + "=geo_shape"));
         boolean isShapeIntersectingBB = false;
@@ -136,7 +136,7 @@ protected void prepareSingleValueGeoPointIndex(final Random random) throws Excep
         expectedDocCountsForSingleGeoPoint = new HashMap<>();
         createIndex("idx_unmapped");
         final Settings settings = Settings.builder()
-            .put(IndexMetadata.SETTING_VERSION_CREATED, version)
+            .put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT)
             .put("index.number_of_shards", 4)
             .put("index.number_of_replicas", 0)
             .build();
@@ -160,7 +160,7 @@ protected void prepareSingleValueGeoPointIndex(final Random random) throws Excep
 
     protected void prepareMultiValuedGeoPointIndex(final Random random) throws Exception {
         multiValuedExpectedDocCountsGeoPoint = new HashMap<>();
-        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, version).build();
+        final Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build();
         final List<IndexRequestBuilder> cities = new ArrayList<>();
         assertAcked(
             prepareCreate("multi_valued_idx").setSettings(settings)
diff --git a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
index 39c2d67ac0b85..0eab6334854ab 100644
--- a/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
+++ b/modules/ingest-common/src/main/java/org/opensearch/ingest/common/DotExpanderProcessor.java
@@ -118,25 +118,15 @@ public Processor create(
         ) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, tag, config, "field");
             if (field.contains(".") == false) {
-                throw ConfigurationUtils.newConfigurationException(
-                    ConfigurationUtils.TAG_KEY,
-                    tag,
-                    "field",
-                    "field does not contain a dot"
-                );
+                throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "field does not contain a dot");
             }
             if (field.indexOf('.') == 0 || field.lastIndexOf('.') == field.length() - 1) {
-                throw ConfigurationUtils.newConfigurationException(
-                    ConfigurationUtils.TAG_KEY,
-                    tag,
-                    "field",
-                    "Field can't start or end with a dot"
-                );
+                throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "Field can't start or end with a dot");
             }
             int firstIndex = -1;
             for (int index = field.indexOf('.'); index != -1; index = field.indexOf('.', index + 1)) {
                 if (index - firstIndex == 1) {
-                    throw ConfigurationUtils.newConfigurationException(ConfigurationUtils.TAG_KEY, tag, "field", "No space between dots");
+                    throw ConfigurationUtils.newConfigurationException(TYPE, tag, "field", "No space between dots");
                 }
                 firstIndex = index;
             }
diff --git a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
index 1677f333a4b1c..4970c42163ac3 100644
--- a/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
+++ b/modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java
@@ -116,6 +116,9 @@
 import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_SEND_BUFFER_SIZE;
 import static org.opensearch.http.HttpTransportSettings.SETTING_PIPELINING_MAX_EVENTS;
 
+/**
+ * The HTTP transport implementations based on Netty 4.
+ */
 public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
     private static final Logger logger = LogManager.getLogger(Netty4HttpServerTransport.class);
 
@@ -184,6 +187,17 @@ public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
     private volatile ServerBootstrap serverBootstrap;
     private volatile SharedGroupFactory.SharedGroup sharedGroup;
 
+    /**
+     * Creates new HTTP transport implementations based on Netty 4
+     * @param settings seetings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param sharedGroupFactory shared group factory
+     */
     public Netty4HttpServerTransport(
         Settings settings,
         NetworkService networkService,
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/discovery-ec2/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt b/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/discovery-ec2/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/repository-azure/build.gradle b/plugins/repository-azure/build.gradle
index 26e2b4813b8a5..51f2057b4bedb 100644
--- a/plugins/repository-azure/build.gradle
+++ b/plugins/repository-azure/build.gradle
@@ -56,11 +56,8 @@ dependencies {
   api "io.netty:netty-transport-native-unix-common:${versions.netty}"
   implementation project(':modules:transport-netty4')
   api 'com.azure:azure-storage-blob:12.23.0'
-  api 'org.reactivestreams:reactive-streams:1.0.4'
-  api 'io.projectreactor:reactor-core:3.5.6'
-  api 'io.projectreactor.netty:reactor-netty:1.1.8'
-  api 'io.projectreactor.netty:reactor-netty-core:1.1.8'
-  api 'io.projectreactor.netty:reactor-netty-http:1.1.9'
+  api "io.projectreactor.netty:reactor-netty-core:${versions.reactor_netty}"
+  api "io.projectreactor.netty:reactor-netty-http:${versions.reactor_netty}"
   api "org.slf4j:slf4j-api:${versions.slf4j}"
   api "com.fasterxml.jackson.core:jackson-annotations:${versions.jackson}"
   api "com.fasterxml.jackson.core:jackson-databind:${versions.jackson_databind}"
@@ -101,10 +98,6 @@ thirdPartyAudit {
     'com.azure.storage.internal.avro.implementation.schema.AvroSchema',
     'com.ctc.wstx.shaded.msv_core.driver.textui.Driver',
     'io.micrometer.context.ContextAccessor',
-    'io.micrometer.context.ContextRegistry',
-    'io.micrometer.context.ContextSnapshot',
-    'io.micrometer.context.ContextSnapshot$Scope',
-    'io.micrometer.core.instrument.Clock',
     'io.micrometer.core.instrument.Counter',
     'io.micrometer.core.instrument.Counter$Builder',
     'io.micrometer.core.instrument.DistributionSummary',
@@ -114,14 +107,10 @@ thirdPartyAudit {
     'io.micrometer.core.instrument.Meter',
     'io.micrometer.core.instrument.MeterRegistry',
     'io.micrometer.core.instrument.Metrics',
-    'io.micrometer.core.instrument.Tag',
-    'io.micrometer.core.instrument.Tags',
     'io.micrometer.core.instrument.Timer',
     'io.micrometer.core.instrument.Timer$Builder',
     'io.micrometer.core.instrument.Timer$Sample',
-    'io.micrometer.core.instrument.binder.jvm.ExecutorServiceMetrics',
     'io.micrometer.core.instrument.composite.CompositeMeterRegistry',
-    'io.micrometer.core.instrument.search.Search',
     'io.netty.channel.epoll.Epoll',
     'io.netty.channel.epoll.EpollDatagramChannel',
     'io.netty.channel.epoll.EpollServerSocketChannel',
@@ -168,9 +157,6 @@ thirdPartyAudit {
     'org.slf4j.impl.StaticLoggerBinder',
     'org.slf4j.impl.StaticMDCBinder',
     'org.slf4j.impl.StaticMarkerBinder',
-    'reactor.blockhound.BlockHound$Builder',
-    'reactor.blockhound.integration.BlockHoundIntegration',
-    'io.micrometer.context.ThreadLocalAccessor',
     'io.micrometer.common.KeyValue',
     'io.micrometer.common.KeyValues',
     'io.micrometer.common.docs.KeyName',
@@ -190,6 +176,7 @@ thirdPartyAudit {
     'io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler',
     'io.micrometer.tracing.propagation.Propagator',
     'io.micrometer.core.instrument.observation.MeterObservationHandler',
+    'io.micrometer.core.instrument.Tags',
     'io.micrometer.observation.ObservationHandler',
     'io.micrometer.observation.ObservationRegistry',
     'io.micrometer.observation.ObservationRegistry$ObservationConfig',
@@ -210,8 +197,7 @@ thirdPartyAudit {
     'com.google.common.util.concurrent.AbstractFuture$UnsafeAtomicHelper$1',
     'com.google.common.hash.LittleEndianByteArray$UnsafeByteArray',
     'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator',
-    'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1',
-    'reactor.core.publisher.Traces$SharedSecretsCallSiteSupplierFactory$TracingException'
+    'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1'
   )
 }
 
diff --git a/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/repository-azure/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt b/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/repository-azure/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1 b/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1
deleted file mode 100644
index ad9b7263e7b38..0000000000000
--- a/plugins/repository-azure/licenses/reactor-core-3.5.6.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-027fdc551537b349389176a23a192f11a7a3d7de
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
deleted file mode 100644
index 6b6bf1903b16c..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d53a9d7d0395285f4c81664494fcd61477626e32
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.12.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.12.jar.sha1
new file mode 100644
index 0000000000000..352d69396d0c9
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-core-1.1.12.jar.sha1
@@ -0,0 +1 @@
+378dc5a375e6440099e837b22cf4b01341cbe4ea
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
deleted file mode 100644
index 707631f4dfe0c..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-48999c4ae27cdcee5eaff9dfd150a8b64624f0f5
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-http-1.1.12.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-http-1.1.12.jar.sha1
new file mode 100644
index 0000000000000..1bcb0e0c52950
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-http-1.1.12.jar.sha1
@@ -0,0 +1 @@
+e839fadb8f45d8a7a2783466faedd03373366c23
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1
deleted file mode 100644
index 96deead2c75d1..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-http-1.1.9.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-408b3037133f2e8ab0f195ccd3f807026be9b860
\ No newline at end of file
diff --git a/plugins/repository-s3/build.gradle b/plugins/repository-s3/build.gradle
index 44fd45b265e82..560d12d14395d 100644
--- a/plugins/repository-s3/build.gradle
+++ b/plugins/repository-s3/build.gradle
@@ -70,7 +70,6 @@ dependencies {
   api "software.amazon.awssdk:sts:${versions.aws}"
   api "software.amazon.awssdk:netty-nio-client:${versions.aws}"
 
-  api "org.reactivestreams:reactive-streams:${versions.reactivestreams}"
   api "org.apache.httpcomponents:httpclient:${versions.httpclient}"
   api "org.apache.httpcomponents:httpcore:${versions.httpcore}"
   api "commons-logging:commons-logging:${versions.commonslogging}"
diff --git a/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1 b/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1
deleted file mode 100644
index 45a80e3f7e361..0000000000000
--- a/plugins/repository-s3/licenses/reactive-streams-1.0.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-3864a1320d97d7b045f729a326e1e077661f31b7
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt b/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt
deleted file mode 100644
index 1e3c7e7c77495..0000000000000
--- a/plugins/repository-s3/licenses/reactive-streams-LICENSE.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-MIT No Attribution
-
-Copyright 2014 Reactive Streams
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/reactive-streams-NOTICE.txt b/plugins/repository-s3/licenses/reactive-streams-NOTICE.txt
deleted file mode 100644
index e69de29bb2d1d..0000000000000
diff --git a/plugins/transport-reactor-netty4/build.gradle b/plugins/transport-reactor-netty4/build.gradle
new file mode 100644
index 0000000000000..7d7eb330b4a55
--- /dev/null
+++ b/plugins/transport-reactor-netty4/build.gradle
@@ -0,0 +1,264 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+import org.opensearch.gradle.info.BuildParams
+import org.opensearch.gradle.test.RestIntegTestTask
+import org.opensearch.gradle.test.TestTask
+import org.opensearch.gradle.test.rest.JavaRestTestPlugin
+import org.opensearch.gradle.test.InternalClusterTestPlugin
+
+apply plugin: 'opensearch.yaml-rest-test'
+apply plugin: 'opensearch.java-rest-test'
+apply plugin: 'opensearch.internal-cluster-test'
+
+// The transport-reactor-netty4 plugin is published to maven
+apply plugin: 'opensearch.publish'
+
+opensearchplugin {
+  description 'Reactor Netty 4 based transport implementation'
+  classname 'org.opensearch.transport.reactor.ReactorNetty4Plugin'
+  hasClientJar = true
+}
+
+dependencies {
+  // network stack
+  api "io.netty:netty-buffer:${versions.netty}"
+  api "io.netty:netty-codec:${versions.netty}"
+  api "io.netty:netty-codec-dns:${versions.netty}"
+  api "io.netty:netty-codec-http:${versions.netty}"
+  api "io.netty:netty-codec-http2:${versions.netty}"
+  api "io.netty:netty-common:${versions.netty}"
+  api "io.netty:netty-handler:${versions.netty}"
+  api "io.netty:netty-resolver-dns:${versions.netty}"
+  api "io.netty:netty-resolver:${versions.netty}"
+  api "io.netty:netty-transport:${versions.netty}"
+  api "io.netty:netty-transport-native-unix-common:${versions.netty}"
+
+  api "io.projectreactor.netty:reactor-netty-http:${versions.reactor_netty}"
+  api "io.projectreactor.netty:reactor-netty-core:${versions.reactor_netty}"
+
+  testImplementation "org.apache.logging.log4j:log4j-slf4j-impl:${versions.log4j}"
+  testImplementation "io.projectreactor:reactor-test:${versions.reactor}"
+  testImplementation project(":modules:transport-netty4")
+}
+
+restResources {
+  restApi {
+    includeCore '_common', 'cluster', 'nodes'
+  }
+}
+
+tasks.named("dependencyLicenses").configure {
+  mapping from: /netty-.*/, to: 'netty'
+  mapping from: /reactor-.*/, to: 'reactor'
+}
+
+// TODO: Remove that once we have a complete test suite
+testingConventions.enabled = false
+
+test {
+  /*
+   * We have to disable setting the number of available processors as tests in the same JVM randomize processors and will step on each
+   * other if we allow them to set the number of available processors as it's set-once in Netty.
+   */
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+internalClusterTest {
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+javaRestTest {
+  systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
+}
+
+thirdPartyAudit {
+  ignoreMissingClasses(
+    'com.aayushatharva.brotli4j.Brotli4jLoader',
+    'com.aayushatharva.brotli4j.decoder.DecoderJNI$Status',
+    'com.aayushatharva.brotli4j.decoder.DecoderJNI$Wrapper',
+    'com.aayushatharva.brotli4j.encoder.BrotliEncoderChannel',
+    'com.aayushatharva.brotli4j.encoder.Encoder$Mode',
+    'com.aayushatharva.brotli4j.encoder.Encoder$Parameters',
+    // classes are missing
+
+    // from io.netty.logging.CommonsLoggerFactory (netty)
+    'org.apache.commons.logging.Log',
+    'org.apache.commons.logging.LogFactory',
+
+    // from Log4j (deliberate, Netty will fallback to Log4j 2)
+    'org.apache.log4j.Level',
+    'org.apache.log4j.Logger',
+
+    // from io.netty.handler.ssl.OpenSslEngine (netty)
+    'io.netty.internal.tcnative.Buffer',
+    'io.netty.internal.tcnative.CertificateCompressionAlgo',
+    'io.netty.internal.tcnative.Library',
+    'io.netty.internal.tcnative.SSL',
+    'io.netty.internal.tcnative.SSLContext',
+    'io.netty.internal.tcnative.SSLPrivateKeyMethod',
+
+    // from io.netty.handler.ssl.util.BouncyCastleSelfSignedCertGenerator (netty)
+    'org.bouncycastle.cert.X509v3CertificateBuilder',
+    'org.bouncycastle.cert.jcajce.JcaX509CertificateConverter',
+    'org.bouncycastle.operator.jcajce.JcaContentSignerBuilder',
+    'org.bouncycastle.openssl.PEMEncryptedKeyPair',
+    'org.bouncycastle.openssl.PEMParser',
+    'org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter',
+    'org.bouncycastle.openssl.jcajce.JceOpenSSLPKCS8DecryptorProviderBuilder',
+    'org.bouncycastle.openssl.jcajce.JcePEMDecryptorProviderBuilder',
+    'org.bouncycastle.pkcs.PKCS8EncryptedPrivateKeyInfo',
+
+    // from io.netty.handler.ssl.JettyNpnSslEngine (netty)
+    'org.eclipse.jetty.npn.NextProtoNego$ClientProvider',
+    'org.eclipse.jetty.npn.NextProtoNego$ServerProvider',
+    'org.eclipse.jetty.npn.NextProtoNego',
+
+    // from io.netty.handler.codec.marshalling.ChannelBufferByteInput (netty)
+    'org.jboss.marshalling.ByteInput',
+
+    // from io.netty.handler.codec.marshalling.ChannelBufferByteOutput (netty)
+    'org.jboss.marshalling.ByteOutput',
+
+    // from io.netty.handler.codec.marshalling.CompatibleMarshallingEncoder (netty)
+    'org.jboss.marshalling.Marshaller',
+
+    // from io.netty.handler.codec.marshalling.ContextBoundUnmarshallerProvider (netty)
+    'org.jboss.marshalling.MarshallerFactory',
+    'org.jboss.marshalling.MarshallingConfiguration',
+    'org.jboss.marshalling.Unmarshaller',
+
+    // from io.netty.util.internal.logging.InternalLoggerFactory (netty) - it's optional
+    'org.slf4j.helpers.FormattingTuple',
+    'org.slf4j.helpers.MessageFormatter',
+    'org.slf4j.Logger',
+    'org.slf4j.LoggerFactory',
+    'org.slf4j.spi.LocationAwareLogger',
+
+    'com.google.protobuf.nano.CodedOutputByteBufferNano',
+    'com.google.protobuf.nano.MessageNano',
+    'com.ning.compress.BufferRecycler',
+    'com.ning.compress.lzf.ChunkDecoder',
+    'com.ning.compress.lzf.ChunkEncoder',
+    'com.ning.compress.lzf.LZFChunk',
+    'com.ning.compress.lzf.LZFEncoder',
+    'com.ning.compress.lzf.util.ChunkDecoderFactory',
+    'com.ning.compress.lzf.util.ChunkEncoderFactory',
+    'lzma.sdk.lzma.Encoder',
+    'net.jpountz.lz4.LZ4Compressor',
+    'net.jpountz.lz4.LZ4Factory',
+    'net.jpountz.lz4.LZ4FastDecompressor',
+    'net.jpountz.xxhash.XXHash32',
+    'net.jpountz.xxhash.XXHashFactory',
+    'io.netty.internal.tcnative.AsyncSSLPrivateKeyMethod',
+    'io.netty.internal.tcnative.AsyncTask',
+    'io.netty.internal.tcnative.CertificateCallback',
+    'io.netty.internal.tcnative.CertificateVerifier',
+    'io.netty.internal.tcnative.ResultCallback',
+    'io.netty.internal.tcnative.SessionTicketKey',
+    'io.netty.internal.tcnative.SniHostNameMatcher',
+    'io.netty.internal.tcnative.SSL',
+    'io.netty.internal.tcnative.SSLSession',
+    'io.netty.internal.tcnative.SSLSessionCache',
+    'io.netty.channel.epoll.Epoll',
+    'io.netty.channel.epoll.EpollDatagramChannel',
+    'io.netty.channel.epoll.EpollServerSocketChannel',
+    'io.netty.channel.epoll.EpollSocketChannel',
+    'io.netty.channel.kqueue.KQueue',
+    'io.netty.channel.kqueue.KQueueDatagramChannel',
+    'io.netty.channel.kqueue.KQueueServerSocketChannel',
+    'io.netty.channel.kqueue.KQueueSocketChannel',
+    'io.netty.handler.codec.haproxy.HAProxyMessage',
+    'io.netty.handler.codec.haproxy.HAProxyMessageDecoder',
+    'io.netty.handler.proxy.ProxyHandler',
+    'io.netty.incubator.channel.uring.IOUring',
+    'io.netty.incubator.channel.uring.IOUringDatagramChannel',
+    'io.netty.incubator.channel.uring.IOUringServerSocketChannel',
+    'io.netty.incubator.channel.uring.IOUringSocketChannel',
+
+    'org.eclipse.jetty.alpn.ALPN$ClientProvider',
+    'org.eclipse.jetty.alpn.ALPN$ServerProvider',
+    'org.eclipse.jetty.alpn.ALPN',
+
+    'org.conscrypt.AllocatedBuffer',
+    'org.conscrypt.BufferAllocator',
+    'org.conscrypt.Conscrypt',
+    'org.conscrypt.HandshakeListener',
+
+    'reactor.blockhound.BlockHound$Builder',
+    'reactor.blockhound.integration.BlockHoundIntegration',
+
+    'io.micrometer.common.KeyValue',
+    'io.micrometer.common.KeyValues',
+    'io.micrometer.common.docs.KeyName',
+    'io.micrometer.context.ContextAccessor',
+    'io.micrometer.core.instrument.Counter',
+    'io.micrometer.core.instrument.Counter$Builder',
+    'io.micrometer.core.instrument.DistributionSummary',
+    'io.micrometer.core.instrument.DistributionSummary$Builder',
+    'io.micrometer.core.instrument.Gauge',
+    'io.micrometer.core.instrument.Gauge$Builder',
+    'io.micrometer.core.instrument.Meter',
+    'io.micrometer.core.instrument.Meter$Type',
+    'io.micrometer.core.instrument.MeterRegistry',
+    'io.micrometer.core.instrument.Metrics',
+    'io.micrometer.core.instrument.Tags',
+    'io.micrometer.core.instrument.Timer',
+    'io.micrometer.core.instrument.Timer$Builder',
+    'io.micrometer.core.instrument.Timer$Sample',
+    'io.micrometer.core.instrument.composite.CompositeMeterRegistry',
+    'io.micrometer.core.instrument.docs.MeterDocumentation',
+    'io.micrometer.core.instrument.observation.MeterObservationHandler',
+    'io.micrometer.observation.Observation',
+    'io.micrometer.observation.Observation$Context',
+    'io.micrometer.observation.ObservationHandler',
+    'io.micrometer.observation.ObservationRegistry',
+    'io.micrometer.observation.ObservationRegistry$ObservationConfig',
+    'io.micrometer.observation.docs.ObservationDocumentation',
+    'io.micrometer.observation.transport.ReceiverContext',
+    'io.micrometer.observation.transport.RequestReplyReceiverContext',
+    'io.micrometer.observation.transport.RequestReplySenderContext',
+    'io.micrometer.observation.transport.SenderContext',
+    'io.micrometer.tracing.Span',
+    'io.micrometer.tracing.Tracer',
+    'io.micrometer.tracing.docs.SpanDocumentation',
+    'io.micrometer.tracing.handler.DefaultTracingObservationHandler',
+    'io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler',
+    'io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler',
+    'io.micrometer.tracing.propagation.Propagator'
+  )
+
+  ignoreViolations(
+    'io.netty.util.internal.PlatformDependent0',
+    'io.netty.util.internal.PlatformDependent0$1',
+    'io.netty.util.internal.PlatformDependent0$2',
+    'io.netty.util.internal.PlatformDependent0$3',
+    'io.netty.util.internal.PlatformDependent0$4',
+    'io.netty.util.internal.PlatformDependent0$6',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueConsumerNodeRef',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueProducerNodeRef',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueProducerFields',
+    'io.netty.util.internal.shaded.org.jctools.queues.LinkedQueueNode',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueConsumerIndexField',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerIndexField',
+    'io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerLimitField',
+    'io.netty.util.internal.shaded.org.jctools.util.UnsafeAccess',
+    'io.netty.util.internal.shaded.org.jctools.util.UnsafeRefArrayAccess',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$1',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$2',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$3',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$4',
+    'io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator$5'
+  )
+}
diff --git a/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt b/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt
new file mode 100644
index 0000000000000..d645695673349
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-LICENSE.txt
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
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+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt b/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt
new file mode 100644
index 0000000000000..5bbf91a14de23
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-NOTICE.txt
@@ -0,0 +1,116 @@
+
+                            The Netty Project
+                            =================
+
+Please visit the Netty web site for more information:
+
+  * http://netty.io/
+
+Copyright 2011 The Netty Project
+
+The Netty Project licenses this file to you under the Apache License,
+version 2.0 (the "License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at:
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations
+under the License.
+
+Also, please refer to each LICENSE.<component>.txt file, which is located in
+the 'license' directory of the distribution file, for the license terms of the
+components that this product depends on.
+
+-------------------------------------------------------------------------------
+This product contains the extensions to Java Collections Framework which has
+been derived from the works by JSR-166 EG, Doug Lea, and Jason T. Greene:
+
+  * LICENSE:
+    * license/LICENSE.jsr166y.txt (Public Domain)
+  * HOMEPAGE:
+    * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/
+    * http://viewvc.jboss.org/cgi-bin/viewvc.cgi/jbosscache/experimental/jsr166/
+
+This product contains a modified version of Robert Harder's Public Domain
+Base64 Encoder and Decoder, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.base64.txt (Public Domain)
+  * HOMEPAGE:
+    * http://iharder.sourceforge.net/current/java/base64/
+
+This product contains a modified version of 'JZlib', a re-implementation of
+zlib in pure Java, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.jzlib.txt (BSD Style License)
+  * HOMEPAGE:
+    * http://www.jcraft.com/jzlib/
+
+This product contains a modified version of 'Webbit', a Java event based
+WebSocket and HTTP server:
+
+  * LICENSE:
+    * license/LICENSE.webbit.txt (BSD License)
+  * HOMEPAGE:
+    * https://github.com/joewalnes/webbit
+
+This product optionally depends on 'Protocol Buffers', Google's data
+interchange format, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.protobuf.txt (New BSD License)
+  * HOMEPAGE:
+    * http://code.google.com/p/protobuf/
+
+This product optionally depends on 'Bouncy Castle Crypto APIs' to generate
+a temporary self-signed X.509 certificate when the JVM does not provide the
+equivalent functionality.  It can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.bouncycastle.txt (MIT License)
+  * HOMEPAGE:
+    * http://www.bouncycastle.org/
+
+This product optionally depends on 'SLF4J', a simple logging facade for Java,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.slf4j.txt (MIT License)
+  * HOMEPAGE:
+    * http://www.slf4j.org/
+
+This product optionally depends on 'Apache Commons Logging', a logging
+framework, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.commons-logging.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://commons.apache.org/logging/
+
+This product optionally depends on 'Apache Log4J', a logging framework,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.log4j.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://logging.apache.org/log4j/
+
+This product optionally depends on 'JBoss Logging', a logging framework,
+which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.jboss-logging.txt (GNU LGPL 2.1)
+  * HOMEPAGE:
+    * http://anonsvn.jboss.org/repos/common/common-logging-spi/
+
+This product optionally depends on 'Apache Felix', an open source OSGi
+framework implementation, which can be obtained at:
+
+  * LICENSE:
+    * license/LICENSE.felix.txt (Apache License 2.0)
+  * HOMEPAGE:
+    * http://felix.apache.org/
diff --git a/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..aaf2e35302d77
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-buffer-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+39b05d2d4027971bf99111a9be1d7035a116bb55
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..a77333ea8ae47
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+9c3c71e7cf3b8ce3bfc9fa52a524b9ca7ddf259c
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..dfa4a0fbea94c
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-dns-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+663b1b7bf3ff0f12fde4df20c72d9e94584ebffa
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..6f26bf4e6a9b5
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-http-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+992623e7d8f2d96e41faf1687bb963f5433e3517
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..bf5605151406e
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-codec-http2-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+cbf1a430ea44dbdedbcde16b185cbb95f28d72c7
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-common-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-common-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..d2ff72db60d1f
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-common-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+847f942381145de23f21c836d05b0677474271d3
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..f12a6046e96d0
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-handler-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+4c0acdb8bb73647ebb3847ac2d503d53d72c02b4
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..8e4179ba15942
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-resolver-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+fe62f9ccd41b8660d07639dbbab8ae1edd6f2720
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..0948daa05fff6
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-resolver-dns-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+62dbdf5f25eda75ea8456be1ed72b3fcb0d18774
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..ab2819da570fd
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-transport-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+6620fbfb47667a5eb6050e35c7b4c88000bcd77f
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.100.Final.jar.sha1 b/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.100.Final.jar.sha1
new file mode 100644
index 0000000000000..30d7758302e37
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/netty-transport-native-unix-common-4.1.100.Final.jar.sha1
@@ -0,0 +1 @@
+648ff5571022dbfa6789122e3872477bbf67fa7b
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt b/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt
new file mode 100644
index 0000000000000..e5583c184e67a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-LICENSE.txt
@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
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+
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+
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+      not limited to compiled object code, generated documentation,
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+
+      "Work" shall mean the work of authorship, whether in Source or
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+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
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+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
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+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
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+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
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+      (except as stated in this section) patent license to make, have made,
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+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
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+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
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+          within a display generated by the Derivative Works, if and
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
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+      and charge a fee for, acceptance of support, warranty, indemnity,
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+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/crypto-kms/licenses/reactive-streams-NOTICE.txt b/plugins/transport-reactor-netty4/licenses/reactor-NOTICE.txt
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-NOTICE.txt
rename to plugins/transport-reactor-netty4/licenses/reactor-NOTICE.txt
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.12.jar.sha1 b/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.12.jar.sha1
new file mode 100644
index 0000000000000..352d69396d0c9
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-netty-core-1.1.12.jar.sha1
@@ -0,0 +1 @@
+378dc5a375e6440099e837b22cf4b01341cbe4ea
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.12.jar.sha1 b/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.12.jar.sha1
new file mode 100644
index 0000000000000..1bcb0e0c52950
--- /dev/null
+++ b/plugins/transport-reactor-netty4/licenses/reactor-netty-http-1.1.12.jar.sha1
@@ -0,0 +1 @@
+e839fadb8f45d8a7a2783466faedd03373366c23
\ No newline at end of file
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java
new file mode 100644
index 0000000000000..abbd50bf1b235
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/OpenSearchReactorNetty4IntegTestCase.java
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch;
+
+import org.opensearch.common.network.NetworkModule;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.transport.Netty4ModulePlugin;
+import org.opensearch.transport.reactor.ReactorNetty4Plugin;
+import org.opensearch.transport.reactor.netty4.ReactorNetty4Transport;
+
+import java.util.Collection;
+import java.util.List;
+
+public abstract class OpenSearchReactorNetty4IntegTestCase extends OpenSearchIntegTestCase {
+
+    @Override
+    protected boolean ignoreExternalCluster() {
+        return true;
+    }
+
+    @Override
+    protected boolean addMockTransportService() {
+        return false;
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        Settings.Builder builder = Settings.builder().put(super.nodeSettings(nodeOrdinal));
+        // randomize netty settings
+        if (randomBoolean()) {
+            builder.put(ReactorNetty4Transport.SETTING_WORKER_COUNT.getKey(), random().nextInt(3) + 1);
+        }
+        builder.put(NetworkModule.TRANSPORT_TYPE_KEY, Netty4ModulePlugin.NETTY_TRANSPORT_NAME);
+        builder.put(NetworkModule.HTTP_TYPE_KEY, ReactorNetty4Plugin.REACTOR_NETTY_HTTP_TRANSPORT_NAME);
+        return builder.build();
+    }
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return List.of(ReactorNetty4Plugin.class, Netty4ModulePlugin.class);
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java
new file mode 100644
index 0000000000000..833d60375a2bd
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequestSizeLimitIT.java
@@ -0,0 +1,159 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchReactorNetty4IntegTestCase;
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.common.unit.ByteSizeUnit;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.indices.breaker.HierarchyCircuitBreakerService;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.hasSize;
+
+/**
+ * This test checks that in-flight requests are limited on HTTP level and that requests that are excluded from limiting can pass.
+ *
+ * As the same setting is also used to limit in-flight requests on transport level, we avoid transport messages by forcing
+ * a single node "cluster".
+ */
+@ClusterScope(scope = Scope.TEST, supportsDedicatedMasters = false, numClientNodes = 0, numDataNodes = 1)
+public class ReactorNetty4HttpRequestSizeLimitIT extends OpenSearchReactorNetty4IntegTestCase {
+
+    private static final ByteSizeValue LIMIT = new ByteSizeValue(2, ByteSizeUnit.KB);
+
+    @Override
+    protected boolean addMockHttpTransport() {
+        return false; // enable http
+    }
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder()
+            .put(super.nodeSettings(nodeOrdinal))
+            .put(HierarchyCircuitBreakerService.IN_FLIGHT_REQUESTS_CIRCUIT_BREAKER_LIMIT_SETTING.getKey(), LIMIT)
+            .build();
+    }
+
+    public void testLimitsInFlightRequests() throws Exception {
+        ensureGreen();
+
+        // we use the limit size as a (very) rough indication on how many requests we should sent to hit the limit
+        int numRequests = LIMIT.bytesAsInt() / 100;
+
+        StringBuilder bulkRequest = new StringBuilder();
+        for (int i = 0; i < numRequests; i++) {
+            bulkRequest.append("{\"index\": {}}");
+            bulkRequest.append(System.lineSeparator());
+            bulkRequest.append("{ \"field\" : \"value\" }");
+            bulkRequest.append(System.lineSeparator());
+        }
+
+        List<Tuple<String, CharSequence>> requests = new ArrayList<>();
+        for (int i = 0; i < 150; i++) {
+            requests.add(Tuple.tuple("/index/_bulk", bulkRequest));
+        }
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+        try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create(false)) {
+            final Collection<FullHttpResponse> singleResponse = nettyHttpClient.post(transportAddress.address(), requests.subList(0, 1));
+            try {
+                assertThat(singleResponse, hasSize(1));
+                assertAtLeastOnceExpectedStatus(singleResponse, HttpResponseStatus.OK);
+
+                final Collection<FullHttpResponse> multipleResponses = nettyHttpClient.post(transportAddress.address(), requests);
+                try {
+                    assertThat(multipleResponses, hasSize(requests.size()));
+                    assertAtLeastOnceExpectedStatus(multipleResponses, HttpResponseStatus.TOO_MANY_REQUESTS);
+                } finally {
+                    multipleResponses.forEach(ReferenceCounted::release);
+                }
+            } finally {
+                singleResponse.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    public void testDoesNotLimitExcludedRequests() throws Exception {
+        ensureGreen();
+
+        List<Tuple<String, CharSequence>> requestUris = new ArrayList<>();
+        for (int i = 0; i < 1500; i++) {
+            requestUris.add(Tuple.tuple("/_cluster/settings", "{ \"transient\": {\"search.default_search_timeout\": \"40s\" } }"));
+        }
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+        try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create(false)) {
+            final Collection<FullHttpResponse> responses = nettyHttpClient.put(transportAddress.address(), requestUris);
+            try {
+                assertThat(responses, hasSize(requestUris.size()));
+                assertAllInExpectedStatus(responses, HttpResponseStatus.OK);
+            } finally {
+                responses.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    private void assertAtLeastOnceExpectedStatus(Collection<FullHttpResponse> responses, HttpResponseStatus expectedStatus) {
+        long countExpectedStatus = responses.stream().filter(r -> r.status().equals(expectedStatus)).count();
+        assertThat("Expected at least one request with status [" + expectedStatus + "]", countExpectedStatus, greaterThan(0L));
+    }
+
+    private void assertAllInExpectedStatus(Collection<FullHttpResponse> responses, HttpResponseStatus expectedStatus) {
+        long countUnexpectedStatus = responses.stream().filter(r -> r.status().equals(expectedStatus) == false).count();
+        assertThat(
+            "Expected all requests with status [" + expectedStatus + "] but [" + countUnexpectedStatus + "] requests had a different one",
+            countUnexpectedStatus,
+            equalTo(0L)
+        );
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java
new file mode 100644
index 0000000000000..c0e43de06f6ff
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/internalClusterTest/java/org/opensearch/http/reactor/netty4/ReactorNetty4PipeliningIT.java
@@ -0,0 +1,68 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchReactorNetty4IntegTestCase;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+import org.opensearch.test.OpenSearchIntegTestCase.Scope;
+
+import java.util.Collection;
+import java.util.Locale;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+
+@ClusterScope(scope = Scope.TEST, supportsDedicatedMasters = false, numDataNodes = 1)
+public class ReactorNetty4PipeliningIT extends OpenSearchReactorNetty4IntegTestCase {
+
+    @Override
+    protected boolean addMockHttpTransport() {
+        return false; // enable http
+    }
+
+    public void testThatNettyHttpServerSupportsPipelining() throws Exception {
+        String[] requests = new String[] { "/", "/_nodes/stats", "/", "/_cluster/state", "/" };
+
+        HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
+        TransportAddress[] boundAddresses = httpServerTransport.boundAddress().boundAddresses();
+        TransportAddress transportAddress = randomFrom(boundAddresses);
+
+        try (ReactorHttpClient client = ReactorHttpClient.create()) {
+            Collection<FullHttpResponse> responses = client.get(transportAddress.address(), true, requests);
+            try {
+                assertThat(responses, hasSize(5));
+
+                Collection<String> opaqueIds = ReactorHttpClient.returnOpaqueIds(responses);
+                assertOpaqueIdsInOrder(opaqueIds);
+            } finally {
+                responses.forEach(ReferenceCounted::release);
+            }
+        }
+    }
+
+    private void assertOpaqueIdsInOrder(Collection<String> opaqueIds) {
+        // check if opaque ids are monotonically increasing
+        int i = 0;
+        String msg = String.format(Locale.ROOT, "Expected list of opaque ids to be monotonically increasing, got [%s]", opaqueIds);
+        for (String opaqueId : opaqueIds) {
+            assertThat(msg, opaqueId, is(String.valueOf(i++)));
+        }
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java
new file mode 100644
index 0000000000000..bd75227dabd08
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/HttpConversionUtil.java
@@ -0,0 +1,47 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.rest.RestRequest;
+
+import io.netty.handler.codec.http.HttpMethod;
+
+final class HttpConversionUtil {
+    private HttpConversionUtil() {}
+
+    /**
+     * Converts {@link HttpMethod} to {@link RestRequest.Method}
+     * @param method {@link HttpMethod} method
+     * @return corresponding {@link RestRequest.Method}
+     * @throws IllegalArgumentException if HTTP method is not supported
+     */
+    public static RestRequest.Method convertMethod(HttpMethod method) {
+        if (method == HttpMethod.GET) {
+            return RestRequest.Method.GET;
+        } else if (method == HttpMethod.POST) {
+            return RestRequest.Method.POST;
+        } else if (method == HttpMethod.PUT) {
+            return RestRequest.Method.PUT;
+        } else if (method == HttpMethod.DELETE) {
+            return RestRequest.Method.DELETE;
+        } else if (method == HttpMethod.HEAD) {
+            return RestRequest.Method.HEAD;
+        } else if (method == HttpMethod.OPTIONS) {
+            return RestRequest.Method.OPTIONS;
+        } else if (method == HttpMethod.PATCH) {
+            return RestRequest.Method.PATCH;
+        } else if (method == HttpMethod.TRACE) {
+            return RestRequest.Method.TRACE;
+        } else if (method == HttpMethod.CONNECT) {
+            return RestRequest.Method.CONNECT;
+        } else {
+            throw new IllegalArgumentException("Unexpected http method: " + method);
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java
new file mode 100644
index 0000000000000..98b359319ff1b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingHttpChannel.java
@@ -0,0 +1,76 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.http.HttpChannel;
+import org.opensearch.http.HttpResponse;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import reactor.core.publisher.FluxSink;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+class NonStreamingHttpChannel implements HttpChannel {
+    private final HttpServerRequest request;
+    private final HttpServerResponse response;
+    private final CompletableContext<Void> closeContext = new CompletableContext<>();
+    private final FluxSink<HttpContent> emitter;
+
+    NonStreamingHttpChannel(HttpServerRequest request, HttpServerResponse response, FluxSink<HttpContent> emitter) {
+        this.request = request;
+        this.response = response;
+        this.emitter = emitter;
+        this.request.withConnection(connection -> Netty4Utils.addListener(connection.channel().closeFuture(), closeContext));
+    }
+
+    @Override
+    public boolean isOpen() {
+        final AtomicBoolean isOpen = new AtomicBoolean();
+        request.withConnection(connection -> isOpen.set(connection.channel().isOpen()));
+        return isOpen.get();
+    }
+
+    @Override
+    public void close() {
+        request.withConnection(connection -> connection.channel().close());
+    }
+
+    @Override
+    public void addCloseListener(ActionListener<Void> listener) {
+        closeContext.addListener(ActionListener.toBiConsumer(listener));
+    }
+
+    @Override
+    public void sendResponse(HttpResponse response, ActionListener<Void> listener) {
+        emitter.next(createResponse(response));
+        listener.onResponse(null);
+        emitter.complete();
+    }
+
+    @Override
+    public InetSocketAddress getRemoteAddress() {
+        return (InetSocketAddress) response.remoteAddress();
+    }
+
+    @Override
+    public InetSocketAddress getLocalAddress() {
+        return (InetSocketAddress) response.hostAddress();
+    }
+
+    FullHttpResponse createResponse(HttpResponse response) {
+        return (FullHttpResponse) response;
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java
new file mode 100644
index 0000000000000..d43e23e800e65
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/NonStreamingRequestConsumer.java
@@ -0,0 +1,104 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.http.AbstractHttpServerTransport;
+import org.opensearch.http.HttpRequest;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+
+import io.netty.buffer.CompositeByteBuf;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.LastHttpContent;
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import reactor.core.Disposable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.FluxSink;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+class NonStreamingRequestConsumer<T extends HttpContent> implements Consumer<T>, Publisher<HttpContent>, Disposable {
+    private final HttpServerRequest request;
+    private final HttpServerResponse response;
+    private final CompositeByteBuf content;
+    private final Publisher<HttpContent> publisher;
+    private final AbstractHttpServerTransport transport;
+    private final AtomicBoolean disposed = new AtomicBoolean(false);
+    private volatile FluxSink<HttpContent> emitter;
+
+    NonStreamingRequestConsumer(
+        AbstractHttpServerTransport transport,
+        HttpServerRequest request,
+        HttpServerResponse response,
+        int maxCompositeBufferComponents
+    ) {
+        this.transport = transport;
+        this.request = request;
+        this.response = response;
+        this.content = response.alloc().compositeBuffer(maxCompositeBufferComponents);
+        this.publisher = Flux.create(emitter -> register(emitter));
+    }
+
+    private void register(FluxSink<HttpContent> emitter) {
+        this.emitter = emitter.onDispose(this).onCancel(this);
+    }
+
+    @Override
+    public void accept(T message) {
+        try {
+            if (message instanceof LastHttpContent) {
+                process(message, emitter);
+            } else if (message instanceof HttpContent) {
+                process(message, emitter);
+            }
+        } catch (Throwable ex) {
+            emitter.error(ex);
+        }
+    }
+
+    public void process(HttpContent in, FluxSink<HttpContent> emitter) {
+        // Consume request body in full before dispatching it
+        content.addComponent(true, in.content().retain());
+
+        if (in instanceof LastHttpContent) {
+            final NonStreamingHttpChannel channel = new NonStreamingHttpChannel(request, response, emitter);
+            final HttpRequest r = createRequest(request, content);
+
+            try {
+                transport.incomingRequest(r, channel);
+            } catch (Exception ex) {
+                emitter.error(ex);
+                transport.onException(channel, ex);
+            } finally {
+                r.release();
+                if (disposed.compareAndSet(false, true)) {
+                    this.content.release();
+                }
+            }
+        }
+    }
+
+    HttpRequest createRequest(HttpServerRequest request, CompositeByteBuf content) {
+        return new ReactorNetty4HttpRequest(request, content.retain());
+    }
+
+    @Override
+    public void subscribe(Subscriber<? super HttpContent> s) {
+        publisher.subscribe(s);
+    }
+
+    @Override
+    public void dispose() {
+        if (disposed.compareAndSet(false, true)) {
+            this.content.release();
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java
new file mode 100644
index 0000000000000..4406c555a5b04
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpRequest.java
@@ -0,0 +1,272 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpRequest;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.util.AbstractMap;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.stream.Collectors;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.handler.codec.http.DefaultHttpHeaders;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.cookie.Cookie;
+import io.netty.handler.codec.http.cookie.ServerCookieDecoder;
+import io.netty.handler.codec.http.cookie.ServerCookieEncoder;
+import reactor.netty.http.server.HttpServerRequest;
+
+class ReactorNetty4HttpRequest implements HttpRequest {
+    private final String protocol;
+    private final HttpMethod method;
+    private final String uri;
+    private final ByteBuf content;
+    private final HttpHeadersMap headers;
+    private final AtomicBoolean released;
+    private final Exception inboundException;
+    private final boolean pooled;
+
+    ReactorNetty4HttpRequest(HttpServerRequest request, ByteBuf content) {
+        this(request, new HttpHeadersMap(request.requestHeaders()), new AtomicBoolean(false), true, content);
+    }
+
+    ReactorNetty4HttpRequest(HttpServerRequest request, ByteBuf content, Exception inboundException) {
+        this(
+            request.protocol(),
+            request.method(),
+            request.uri(),
+            new HttpHeadersMap(request.requestHeaders()),
+            new AtomicBoolean(false),
+            true,
+            content,
+            inboundException
+        );
+    }
+
+    private ReactorNetty4HttpRequest(
+        HttpServerRequest request,
+        HttpHeadersMap headers,
+        AtomicBoolean released,
+        boolean pooled,
+        ByteBuf content
+    ) {
+        this(request.protocol(), request.method(), request.uri(), headers, released, pooled, content, null);
+    }
+
+    private ReactorNetty4HttpRequest(
+        String protocol,
+        HttpMethod method,
+        String uri,
+        HttpHeadersMap headers,
+        AtomicBoolean released,
+        boolean pooled,
+        ByteBuf content,
+        Exception inboundException
+    ) {
+
+        this.protocol = protocol;
+        this.method = method;
+        this.uri = uri;
+        this.headers = headers;
+        this.content = content;
+        this.pooled = pooled;
+        this.released = released;
+        this.inboundException = inboundException;
+    }
+
+    @Override
+    public RestRequest.Method method() {
+        return HttpConversionUtil.convertMethod(method);
+    }
+
+    @Override
+    public String uri() {
+        return uri;
+    }
+
+    @Override
+    public BytesReference content() {
+        assert released.get() == false;
+        return Netty4Utils.toBytesReference(content);
+    }
+
+    @Override
+    public void release() {
+        if (pooled && released.compareAndSet(false, true)) {
+            content.release();
+        }
+    }
+
+    @Override
+    public HttpRequest releaseAndCopy() {
+        assert released.get() == false;
+        if (pooled == false) {
+            return this;
+        }
+        try {
+            final ByteBuf copiedContent = Unpooled.copiedBuffer(content);
+            return new ReactorNetty4HttpRequest(protocol, method, uri, headers, new AtomicBoolean(false), false, copiedContent, null);
+        } finally {
+            release();
+        }
+    }
+
+    @Override
+    public final Map<String, List<String>> getHeaders() {
+        return headers;
+    }
+
+    @Override
+    public List<String> strictCookies() {
+        String cookieString = headers.httpHeaders.get(HttpHeaderNames.COOKIE);
+        if (cookieString != null) {
+            Set<Cookie> cookies = ServerCookieDecoder.STRICT.decode(cookieString);
+            if (!cookies.isEmpty()) {
+                return ServerCookieEncoder.STRICT.encode(cookies);
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    @Override
+    public HttpVersion protocolVersion() {
+        if (protocol.equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_0.toString())) {
+            return HttpRequest.HttpVersion.HTTP_1_0;
+        } else if (protocol.equals(io.netty.handler.codec.http.HttpVersion.HTTP_1_1.toString())) {
+            return HttpRequest.HttpVersion.HTTP_1_1;
+        } else {
+            throw new IllegalArgumentException("Unexpected http protocol version: " + protocol);
+        }
+    }
+
+    @Override
+    public HttpRequest removeHeader(String header) {
+        HttpHeaders headersWithoutContentTypeHeader = new DefaultHttpHeaders();
+        headersWithoutContentTypeHeader.add(headers.httpHeaders);
+        headersWithoutContentTypeHeader.remove(header);
+
+        return new ReactorNetty4HttpRequest(
+            protocol,
+            method,
+            uri,
+            new HttpHeadersMap(headersWithoutContentTypeHeader),
+            released,
+            pooled,
+            content,
+            null
+        );
+    }
+
+    @Override
+    public ReactorNetty4HttpResponse createResponse(RestStatus status, BytesReference content) {
+        return new ReactorNetty4HttpResponse(
+            headers.httpHeaders,
+            io.netty.handler.codec.http.HttpVersion.valueOf(protocol),
+            status,
+            content
+        );
+    }
+
+    @Override
+    public Exception getInboundException() {
+        return inboundException;
+    }
+
+    /**
+     * A wrapper of {@link HttpHeaders} that implements a map to prevent copying unnecessarily. This class does not support modifications
+     * and due to the underlying implementation, it performs case insensitive lookups of key to values.
+     *
+     * It is important to note that this implementation does have some downsides in that each invocation of the
+     * {@link #values()} and {@link #entrySet()} methods will perform a copy of the values in the HttpHeaders rather than returning a
+     * view of the underlying values.
+     */
+    private static class HttpHeadersMap implements Map<String, List<String>> {
+
+        private final HttpHeaders httpHeaders;
+
+        private HttpHeadersMap(HttpHeaders httpHeaders) {
+            this.httpHeaders = httpHeaders;
+        }
+
+        @Override
+        public int size() {
+            return httpHeaders.size();
+        }
+
+        @Override
+        public boolean isEmpty() {
+            return httpHeaders.isEmpty();
+        }
+
+        @Override
+        public boolean containsKey(Object key) {
+            return key instanceof String && httpHeaders.contains((String) key);
+        }
+
+        @Override
+        public boolean containsValue(Object value) {
+            return value instanceof List && httpHeaders.names().stream().map(httpHeaders::getAll).anyMatch(value::equals);
+        }
+
+        @Override
+        public List<String> get(Object key) {
+            return key instanceof String ? httpHeaders.getAll((String) key) : null;
+        }
+
+        @Override
+        public List<String> put(String key, List<String> value) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public List<String> remove(Object key) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public void putAll(Map<? extends String, ? extends List<String>> m) {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public void clear() {
+            throw new UnsupportedOperationException("modifications are not supported");
+        }
+
+        @Override
+        public Set<String> keySet() {
+            return httpHeaders.names();
+        }
+
+        @Override
+        public Collection<List<String>> values() {
+            return httpHeaders.names().stream().map(k -> Collections.unmodifiableList(httpHeaders.getAll(k))).collect(Collectors.toList());
+        }
+
+        @Override
+        public Set<Entry<String, List<String>>> entrySet() {
+            return httpHeaders.names()
+                .stream()
+                .map(k -> new AbstractMap.SimpleImmutableEntry<>(k, httpHeaders.getAll(k)))
+                .collect(Collectors.toSet());
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java
new file mode 100644
index 0000000000000..c45ad54b668a3
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpResponse.java
@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpResponse;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpVersion;
+
+class ReactorNetty4HttpResponse extends DefaultFullHttpResponse implements HttpResponse {
+    private final HttpHeaders requestHeaders;
+
+    ReactorNetty4HttpResponse(HttpHeaders requestHeaders, HttpVersion version, RestStatus status, BytesReference content) {
+        super(version, HttpResponseStatus.valueOf(status.getStatus()), Netty4Utils.toByteBuf(content));
+        this.requestHeaders = requestHeaders;
+    }
+
+    @Override
+    public void addHeader(String name, String value) {
+        headers().add(name, value);
+    }
+
+    @Override
+    public boolean containsHeader(String name) {
+        return headers().contains(name);
+    }
+
+    public HttpHeaders requestHeaders() {
+        return requestHeaders;
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java
new file mode 100644
index 0000000000000..84360bf028ba9
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerChannel.java
@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.http.HttpServerChannel;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+
+import io.netty.channel.Channel;
+
+class ReactorNetty4HttpServerChannel implements HttpServerChannel {
+    private final Channel channel;
+    private final CompletableContext<Void> closeContext = new CompletableContext<>();
+
+    ReactorNetty4HttpServerChannel(Channel channel) {
+        this.channel = channel;
+        Netty4Utils.addListener(this.channel.closeFuture(), closeContext);
+    }
+
+    @Override
+    public InetSocketAddress getLocalAddress() {
+        return (InetSocketAddress) channel.localAddress();
+    }
+
+    @Override
+    public void addCloseListener(ActionListener<Void> listener) {
+        closeContext.addListener(ActionListener.toBiConsumer(listener));
+    }
+
+    @Override
+    public boolean isOpen() {
+        return channel.isOpen();
+    }
+
+    @Override
+    public void close() {
+        channel.close();
+    }
+
+    @Override
+    public String toString() {
+        return "ReactorNetty4HttpChannel{localAddress=" + getLocalAddress() + "}";
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java
new file mode 100644
index 0000000000000..d4a5a9ad83af6
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransport.java
@@ -0,0 +1,313 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Setting.Property;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+import org.opensearch.common.util.io.IOUtils;
+import org.opensearch.common.util.net.NetUtils;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.http.AbstractHttpServerTransport;
+import org.opensearch.http.HttpChannel;
+import org.opensearch.http.HttpReadTimeoutException;
+import org.opensearch.http.HttpServerChannel;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.opensearch.transport.reactor.netty4.Netty4Utils;
+
+import java.net.InetSocketAddress;
+import java.net.SocketOption;
+import java.time.Duration;
+
+import io.netty.channel.ChannelOption;
+import io.netty.channel.socket.nio.NioChannelOption;
+import io.netty.handler.codec.http.DefaultLastHttpContent;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.timeout.ReadTimeoutException;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Scheduler;
+import reactor.core.scheduler.Schedulers;
+import reactor.netty.DisposableServer;
+import reactor.netty.http.HttpProtocol;
+import reactor.netty.http.server.HttpServer;
+import reactor.netty.http.server.HttpServerRequest;
+import reactor.netty.http.server.HttpServerResponse;
+
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_CHUNK_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_HEADER_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_READ_TIMEOUT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_ALIVE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_COUNT;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_IDLE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_KEEP_INTERVAL;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_NO_DELAY;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_RECEIVE_BUFFER_SIZE;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_REUSE_ADDRESS;
+import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_TCP_SEND_BUFFER_SIZE;
+
+/**
+ * The HTTP transport implementations based on Reactor Netty (see please {@link HttpServer}).
+ */
+public class ReactorNetty4HttpServerTransport extends AbstractHttpServerTransport {
+    private static final String SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = "http.netty.max_composite_buffer_components";
+    private static final ByteSizeValue MTU = new ByteSizeValue(Long.parseLong(System.getProperty("opensearch.net.mtu", "1500")));
+
+    /**
+     * The number of Reactor Netty HTTP workers
+     */
+    public static final Setting<Integer> SETTING_HTTP_WORKER_COUNT = Setting.intSetting("http.netty.worker_count", 0, Property.NodeScope);
+
+    /**
+     * The maximum number of composite components for request accumulation
+     */
+    public static Setting<Integer> SETTING_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = new Setting<>(
+        SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS,
+        (s) -> {
+            ByteSizeValue maxContentLength = SETTING_HTTP_MAX_CONTENT_LENGTH.get(s);
+            /*
+             * Netty accumulates buffers containing data from all incoming network packets that make up one HTTP request in an instance of
+             * io.netty.buffer.CompositeByteBuf (think of it as a buffer of buffers). Once its capacity is reached, the buffer will iterate
+             * over its individual entries and put them into larger buffers (see io.netty.buffer.CompositeByteBuf#consolidateIfNeeded()
+             * for implementation details). We want to to resize that buffer because this leads to additional garbage on the heap and also
+             * increases the application's native memory footprint (as direct byte buffers hold their contents off-heap).
+             *
+             * With this setting we control the CompositeByteBuf's capacity (which is by default 1024, see
+             * io.netty.handler.codec.MessageAggregator#DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS). To determine a proper default capacity for
+             * that buffer, we need to consider that the upper bound for the size of HTTP requests is determined by `maxContentLength`. The
+             * number of buffers that are needed depend on how often Netty reads network packets which depends on the network type (MTU).
+             * We assume here that OpenSearch receives HTTP requests via an Ethernet connection which has a MTU of 1500 bytes.
+             *
+             * Note that we are *not* pre-allocating any memory based on this setting but rather determine the CompositeByteBuf's capacity.
+             * The tradeoff is between less (but larger) buffers that are contained in the CompositeByteBuf and more (but smaller) buffers.
+             * With the default max content length of 100MB and a MTU of 1500 bytes we would allow 69905 entries.
+             */
+            long maxBufferComponentsEstimate = Math.round((double) (maxContentLength.getBytes() / MTU.getBytes()));
+            // clamp value to the allowed range
+            long maxBufferComponents = Math.max(2, Math.min(maxBufferComponentsEstimate, Integer.MAX_VALUE));
+            return String.valueOf(maxBufferComponents);
+            // Netty's CompositeByteBuf implementation does not allow less than two components.
+        },
+        s -> Setting.parseInt(s, 2, Integer.MAX_VALUE, SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS),
+        Property.NodeScope
+    );
+
+    private final SharedGroupFactory sharedGroupFactory;
+    private final int readTimeoutMillis;
+    private final int connectTimeoutMillis;
+    private final int maxCompositeBufferComponents;
+    private final ByteSizeValue maxInitialLineLength;
+    private final ByteSizeValue maxHeaderSize;
+    private final ByteSizeValue maxChunkSize;
+    private volatile SharedGroupFactory.SharedGroup sharedGroup;
+    private volatile DisposableServer disposableServer;
+    private volatile Scheduler scheduler;
+
+    /**
+     * Creates new HTTP transport implementations based on Reactor Netty (see please {@link HttpServer}).
+     * @param settings settings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param sharedGroupFactory shared group factory
+     * @param tracer tracer instance
+     */
+    public ReactorNetty4HttpServerTransport(
+        Settings settings,
+        NetworkService networkService,
+        BigArrays bigArrays,
+        ThreadPool threadPool,
+        NamedXContentRegistry xContentRegistry,
+        Dispatcher dispatcher,
+        ClusterSettings clusterSettings,
+        SharedGroupFactory sharedGroupFactory,
+        Tracer tracer
+    ) {
+        super(settings, networkService, bigArrays, threadPool, xContentRegistry, dispatcher, clusterSettings, tracer);
+        Netty4Utils.setAvailableProcessors(OpenSearchExecutors.NODE_PROCESSORS_SETTING.get(settings));
+        this.readTimeoutMillis = Math.toIntExact(SETTING_HTTP_READ_TIMEOUT.get(settings).getMillis());
+        this.connectTimeoutMillis = Math.toIntExact(SETTING_HTTP_CONNECT_TIMEOUT.get(settings).getMillis());
+        this.sharedGroupFactory = sharedGroupFactory;
+        this.maxCompositeBufferComponents = SETTING_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS.get(settings);
+        this.maxChunkSize = SETTING_HTTP_MAX_CHUNK_SIZE.get(settings);
+        this.maxHeaderSize = SETTING_HTTP_MAX_HEADER_SIZE.get(settings);
+        this.maxInitialLineLength = SETTING_HTTP_MAX_INITIAL_LINE_LENGTH.get(settings);
+    }
+
+    /**
+     * Binds the transport engine to the socket address
+     * @param socketAddress socket address to bind to
+     */
+    @Override
+    protected HttpServerChannel bind(InetSocketAddress socketAddress) throws Exception {
+        final HttpServer server = configureChannelOptions(
+            HttpServer.create()
+                .httpFormDecoder(builder -> builder.scheduler(scheduler))
+                .idleTimeout(Duration.ofMillis(connectTimeoutMillis))
+                .readTimeout(Duration.ofMillis(readTimeoutMillis))
+                .runOn(sharedGroup.getLowLevelGroup())
+                .bindAddress(() -> socketAddress)
+                .compress(true)
+                .httpRequestDecoder(
+                    spec -> spec.maxChunkSize(maxChunkSize.bytesAsInt())
+                        .maxHeaderSize(maxHeaderSize.bytesAsInt())
+                        .maxInitialLineLength(maxInitialLineLength.bytesAsInt())
+                )
+                .protocol(HttpProtocol.HTTP11, HttpProtocol.H2C)
+                .handle((req, res) -> incomingRequest(req, res))
+        );
+
+        disposableServer = server.bindNow();
+        return new ReactorNetty4HttpServerChannel(disposableServer.channel());
+    }
+
+    private HttpServer configureChannelOptions(final HttpServer server1) {
+        HttpServer configured = server1.childOption(ChannelOption.TCP_NODELAY, SETTING_HTTP_TCP_NO_DELAY.get(settings))
+            .childOption(ChannelOption.SO_KEEPALIVE, SETTING_HTTP_TCP_KEEP_ALIVE.get(settings));
+
+        if (SETTING_HTTP_TCP_KEEP_ALIVE.get(settings)) {
+            // Netty logs a warning if it can't set the option, so try this only on supported platforms
+            if (IOUtils.LINUX || IOUtils.MAC_OS_X) {
+                if (SETTING_HTTP_TCP_KEEP_IDLE.get(settings) >= 0) {
+                    final SocketOption<Integer> keepIdleOption = NetUtils.getTcpKeepIdleSocketOptionOrNull();
+                    if (keepIdleOption != null) {
+                        configured = configured.childOption(NioChannelOption.of(keepIdleOption), SETTING_HTTP_TCP_KEEP_IDLE.get(settings));
+                    }
+                }
+                if (SETTING_HTTP_TCP_KEEP_INTERVAL.get(settings) >= 0) {
+                    final SocketOption<Integer> keepIntervalOption = NetUtils.getTcpKeepIntervalSocketOptionOrNull();
+                    if (keepIntervalOption != null) {
+                        configured = configured.childOption(
+                            NioChannelOption.of(keepIntervalOption),
+                            SETTING_HTTP_TCP_KEEP_INTERVAL.get(settings)
+                        );
+                    }
+                }
+                if (SETTING_HTTP_TCP_KEEP_COUNT.get(settings) >= 0) {
+                    final SocketOption<Integer> keepCountOption = NetUtils.getTcpKeepCountSocketOptionOrNull();
+                    if (keepCountOption != null) {
+                        configured = configured.childOption(
+                            NioChannelOption.of(keepCountOption),
+                            SETTING_HTTP_TCP_KEEP_COUNT.get(settings)
+                        );
+                    }
+                }
+            }
+        }
+
+        final ByteSizeValue tcpSendBufferSize = SETTING_HTTP_TCP_SEND_BUFFER_SIZE.get(settings);
+        if (tcpSendBufferSize.getBytes() > 0) {
+            configured = configured.childOption(ChannelOption.SO_SNDBUF, Math.toIntExact(tcpSendBufferSize.getBytes()));
+        }
+
+        final ByteSizeValue tcpReceiveBufferSize = SETTING_HTTP_TCP_RECEIVE_BUFFER_SIZE.get(settings);
+        if (tcpReceiveBufferSize.getBytes() > 0) {
+            configured = configured.childOption(ChannelOption.SO_RCVBUF, Math.toIntExact(tcpReceiveBufferSize.getBytes()));
+        }
+
+        final boolean reuseAddress = SETTING_HTTP_TCP_REUSE_ADDRESS.get(settings);
+        configured = configured.option(ChannelOption.SO_REUSEADDR, reuseAddress);
+        configured = configured.childOption(ChannelOption.SO_REUSEADDR, reuseAddress);
+
+        return configured;
+    }
+
+    /**
+     * Handles incoming Reactor Netty request
+     * @param request request instance
+     * @param response response instances
+     * @return response publisher
+     */
+    protected Publisher<Void> incomingRequest(HttpServerRequest request, HttpServerResponse response) {
+        final NonStreamingRequestConsumer<HttpContent> consumer = new NonStreamingRequestConsumer<>(
+            this,
+            request,
+            response,
+            maxCompositeBufferComponents
+        );
+
+        request.receiveContent().switchIfEmpty(Mono.just(DefaultLastHttpContent.EMPTY_LAST_CONTENT)).subscribe(consumer);
+
+        return Mono.from(consumer).flatMap(hc -> {
+            final FullHttpResponse r = (FullHttpResponse) hc;
+            response.status(r.status());
+            response.trailerHeaders(c -> r.trailingHeaders().forEach(h -> c.add(h.getKey(), h.getValue())));
+            response.chunkedTransfer(false);
+            response.compression(true);
+            r.headers().forEach(h -> response.addHeader(h.getKey(), h.getValue()));
+            return Mono.from(response.sendObject(r.content()));
+        });
+    }
+
+    /**
+     * Called to tear down internal resources
+     */
+    @Override
+    protected void stopInternal() {
+        if (sharedGroup != null) {
+            sharedGroup.shutdown();
+            sharedGroup = null;
+        }
+
+        if (scheduler != null) {
+            scheduler.dispose();
+            scheduler = null;
+        }
+
+        if (disposableServer != null) {
+            disposableServer.disposeNow();
+            disposableServer = null;
+        }
+    }
+
+    /**
+     * Starts the transport
+     */
+    @Override
+    protected void doStart() {
+        boolean success = false;
+        try {
+            scheduler = Schedulers.newBoundedElastic(
+                Schedulers.DEFAULT_BOUNDED_ELASTIC_SIZE,
+                Schedulers.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE,
+                "http-form-decoder"
+            );
+            sharedGroup = sharedGroupFactory.getHttpGroup();
+            bindServer();
+            success = true;
+        } finally {
+            if (success == false) {
+                doStop(); // otherwise we leak threads since we never moved to started
+            }
+        }
+    }
+
+    @Override
+    public void onException(HttpChannel channel, Exception cause) {
+        if (cause instanceof ReadTimeoutException) {
+            super.onException(channel, new HttpReadTimeoutException(readTimeoutMillis, cause));
+        } else {
+            super.onException(channel, cause);
+        }
+    }
+}
diff --git a/server/src/main/java/org/opensearch/common/rounding/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java
similarity index 63%
rename from server/src/main/java/org/opensearch/common/rounding/package-info.java
rename to plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java
index 5fa3e39c6a786..b5ecb0b62f79d 100644
--- a/server/src/main/java/org/opensearch/common/rounding/package-info.java
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/http/reactor/netty4/package-info.java
@@ -6,5 +6,7 @@
  * compatible open source license.
  */
 
-/** Base DateTime rounding package. */
-package org.opensearch.common.rounding;
+/**
+ * The new HTTP transport implementations based on Reactor Netty.
+ */
+package org.opensearch.http.reactor.netty4;
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java
new file mode 100644
index 0000000000000..dc310c3793109
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/ReactorNetty4Plugin.java
@@ -0,0 +1,109 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.transport.reactor;
+
+import org.opensearch.common.SetOnce;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.PageCacheRecycler;
+import org.opensearch.core.indices.breaker.CircuitBreakerService;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport;
+import org.opensearch.plugins.NetworkPlugin;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.telemetry.tracing.Tracer;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+
+/**
+ * The experimental network plugin that introduces new transport implementations based on Reactor Netty.
+ */
+public class ReactorNetty4Plugin extends Plugin implements NetworkPlugin {
+    /**
+     * The name of new experimental HTTP transport implementations based on Reactor Netty.
+     */
+    public static final String REACTOR_NETTY_HTTP_TRANSPORT_NAME = "reactor-netty4";
+
+    private final SetOnce<SharedGroupFactory> groupFactory = new SetOnce<>();
+
+    /**
+     * Default constructor
+     */
+    public ReactorNetty4Plugin() {}
+
+    /**
+     * Returns a list of additional {@link Setting} definitions for this plugin.
+     */
+    @Override
+    public List<Setting<?>> getSettings() {
+        return Arrays.asList(/* no setting registered since we're picking the onces from Netty 4 transport */);
+    }
+
+    /**
+     * Returns a map of {@link HttpServerTransport} suppliers.
+     * See {@link org.opensearch.common.network.NetworkModule#HTTP_TYPE_SETTING} to configure a specific implementation.
+     * @param settings settings
+     * @param networkService network service
+     * @param bigArrays big array allocator
+     * @param pageCacheRecycler page cache recycler instance
+     * @param circuitBreakerService circuit breaker service instance
+     * @param threadPool thread pool instance
+     * @param xContentRegistry XContent registry instance
+     * @param dispatcher dispatcher instance
+     * @param clusterSettings cluster settings
+     * @param tracer tracer instance
+     */
+    @Override
+    public Map<String, Supplier<HttpServerTransport>> getHttpTransports(
+        Settings settings,
+        ThreadPool threadPool,
+        BigArrays bigArrays,
+        PageCacheRecycler pageCacheRecycler,
+        CircuitBreakerService circuitBreakerService,
+        NamedXContentRegistry xContentRegistry,
+        NetworkService networkService,
+        HttpServerTransport.Dispatcher dispatcher,
+        ClusterSettings clusterSettings,
+        Tracer tracer
+    ) {
+        return Collections.singletonMap(
+            REACTOR_NETTY_HTTP_TRANSPORT_NAME,
+            () -> new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry,
+                dispatcher,
+                clusterSettings,
+                getSharedGroupFactory(settings),
+                tracer
+            )
+        );
+    }
+
+    private SharedGroupFactory getSharedGroupFactory(Settings settings) {
+        final SharedGroupFactory groupFactory = this.groupFactory.get();
+        if (groupFactory != null) {
+            assert groupFactory.getSettings().equals(settings) : "Different settings than originally provided";
+            return groupFactory;
+        } else {
+            this.groupFactory.set(new SharedGroupFactory(settings));
+            return this.groupFactory.get();
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java
new file mode 100644
index 0000000000000..ab7de33c8e673
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/SharedGroupFactory.java
@@ -0,0 +1,164 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.transport.reactor;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.concurrent.AbstractRefCounted;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport;
+import org.opensearch.transport.TcpTransport;
+import org.opensearch.transport.reactor.netty4.ReactorNetty4Transport;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.util.concurrent.Future;
+
+import static org.opensearch.common.util.concurrent.OpenSearchExecutors.daemonThreadFactory;
+
+/**
+ * Creates and returns {@link io.netty.channel.EventLoopGroup} instances. It will return a shared group for
+ * both {@link #getHttpGroup()} and {@link #getTransportGroup()} if
+ * {@link org.opensearch.http.reactor.netty4.ReactorNetty4HttpServerTransport#SETTING_HTTP_WORKER_COUNT} is configured to be 0.
+ * If that setting is not 0, then it will return a different group in the {@link #getHttpGroup()} call.
+ */
+public final class SharedGroupFactory {
+
+    private static final Logger logger = LogManager.getLogger(SharedGroupFactory.class);
+
+    private final Settings settings;
+    private final int workerCount;
+    private final int httpWorkerCount;
+
+    private RefCountedGroup genericGroup;
+    private SharedGroup dedicatedHttpGroup;
+
+    /**
+     * Creates new shared group factory instance from settings
+     * @param settings settings
+     */
+    public SharedGroupFactory(Settings settings) {
+        this.settings = settings;
+        this.workerCount = ReactorNetty4Transport.SETTING_WORKER_COUNT.get(settings);
+        this.httpWorkerCount = ReactorNetty4HttpServerTransport.SETTING_HTTP_WORKER_COUNT.get(settings);
+    }
+
+    Settings getSettings() {
+        return settings;
+    }
+
+    /**
+     * Gets the number of configured transport workers
+     * @return the number of configured transport workers
+     */
+    public int getTransportWorkerCount() {
+        return workerCount;
+    }
+
+    /**
+     * Gets transport shared group
+     * @return transport shared group
+     */
+    public synchronized SharedGroup getTransportGroup() {
+        return getGenericGroup();
+    }
+
+    /**
+     * Gets HTTP transport shared group
+     * @return HTTP transport shared group
+     */
+    public synchronized SharedGroup getHttpGroup() {
+        if (httpWorkerCount == 0) {
+            return getGenericGroup();
+        } else {
+            if (dedicatedHttpGroup == null) {
+                NioEventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+                    httpWorkerCount,
+                    daemonThreadFactory(settings, HttpServerTransport.HTTP_SERVER_WORKER_THREAD_NAME_PREFIX)
+                );
+                dedicatedHttpGroup = new SharedGroup(new RefCountedGroup(eventLoopGroup));
+            }
+            return dedicatedHttpGroup;
+        }
+    }
+
+    private SharedGroup getGenericGroup() {
+        if (genericGroup == null) {
+            EventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+                workerCount,
+                daemonThreadFactory(settings, TcpTransport.TRANSPORT_WORKER_THREAD_NAME_PREFIX)
+            );
+            this.genericGroup = new RefCountedGroup(eventLoopGroup);
+        } else {
+            genericGroup.incRef();
+        }
+        return new SharedGroup(genericGroup);
+    }
+
+    private static class RefCountedGroup extends AbstractRefCounted {
+
+        public static final String NAME = "ref-counted-event-loop-group";
+        private final EventLoopGroup eventLoopGroup;
+
+        private RefCountedGroup(EventLoopGroup eventLoopGroup) {
+            super(NAME);
+            this.eventLoopGroup = eventLoopGroup;
+        }
+
+        @Override
+        protected void closeInternal() {
+            Future<?> shutdownFuture = eventLoopGroup.shutdownGracefully(0, 5, TimeUnit.SECONDS);
+            shutdownFuture.awaitUninterruptibly();
+            if (shutdownFuture.isSuccess() == false) {
+                logger.warn("Error closing netty event loop group", shutdownFuture.cause());
+            }
+        }
+    }
+
+    /**
+     * Wraps the {@link RefCountedGroup}. Calls {@link RefCountedGroup#decRef()} on close. After close,
+     * this wrapped instance can no longer be used.
+     */
+    public static class SharedGroup {
+
+        private final RefCountedGroup refCountedGroup;
+
+        private final AtomicBoolean isOpen = new AtomicBoolean(true);
+
+        private SharedGroup(RefCountedGroup refCountedGroup) {
+            this.refCountedGroup = refCountedGroup;
+        }
+
+        /**
+         * Gets Netty's {@link EventLoopGroup} instance
+         * @return Netty's {@link EventLoopGroup} instance
+         */
+        public EventLoopGroup getLowLevelGroup() {
+            return refCountedGroup.eventLoopGroup;
+        }
+
+        /**
+         * Decreases the reference to underlying  {@link EventLoopGroup} instance
+         */
+        public void shutdown() {
+            if (isOpen.compareAndSet(true, false)) {
+                refCountedGroup.decRef();
+            }
+        }
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java
new file mode 100644
index 0000000000000..8ec432b7dd5cd
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/Netty4Utils.java
@@ -0,0 +1,142 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.transport.reactor.netty4;
+
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.BytesRefIterator;
+import org.opensearch.ExceptionsHelper;
+import org.opensearch.common.Booleans;
+import org.opensearch.common.concurrent.CompletableContext;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.core.common.bytes.BytesReference;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.CompositeByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.util.NettyRuntime;
+
+/**
+ * Shameless copy of Netty4Utils from transport-netty4 module
+ */
+public final class Netty4Utils {
+    private static final AtomicBoolean isAvailableProcessorsSet = new AtomicBoolean();
+
+    /**
+     * Utility class
+     */
+    private Netty4Utils() {}
+
+    /**
+     * Set the number of available processors that Netty uses for sizing various resources (e.g., thread pools).
+     *
+     * @param availableProcessors the number of available processors
+     * @throws IllegalStateException if available processors was set previously and the specified value does not match the already-set value
+     */
+    public static void setAvailableProcessors(final int availableProcessors) {
+        // we set this to false in tests to avoid tests that randomly set processors from stepping on each other
+        final boolean set = Booleans.parseBoolean(System.getProperty("opensearch.set.netty.runtime.available.processors", "true"));
+        if (!set) {
+            return;
+        }
+
+        /*
+         * This can be invoked twice, once from Netty4Transport and another time from Netty4HttpServerTransport; however,
+         * Netty4Runtime#availableProcessors forbids settings the number of processors twice so we prevent double invocation here.
+         */
+        if (isAvailableProcessorsSet.compareAndSet(false, true)) {
+            NettyRuntime.setAvailableProcessors(availableProcessors);
+        } else if (availableProcessors != NettyRuntime.availableProcessors()) {
+            /*
+             * We have previously set the available processors yet either we are trying to set it to a different value now or there is a bug
+             * in Netty and our previous value did not take, bail.
+             */
+            final String message = String.format(
+                Locale.ROOT,
+                "available processors value [%d] did not match current value [%d]",
+                availableProcessors,
+                NettyRuntime.availableProcessors()
+            );
+            throw new IllegalStateException(message);
+        }
+    }
+
+    /**
+     * Turns the given BytesReference into a ByteBuf. Note: the returned ByteBuf will reference the internal
+     * pages of the BytesReference. Don't free the bytes of reference before the ByteBuf goes out of scope.
+     * @param reference reference to convert
+     */
+    public static ByteBuf toByteBuf(final BytesReference reference) {
+        if (reference.length() == 0) {
+            return Unpooled.EMPTY_BUFFER;
+        }
+        final BytesRefIterator iterator = reference.iterator();
+        // usually we have one, two, or three components from the header, the message, and a buffer
+        final List<ByteBuf> buffers = new ArrayList<>(3);
+        try {
+            BytesRef slice;
+            while ((slice = iterator.next()) != null) {
+                buffers.add(Unpooled.wrappedBuffer(slice.bytes, slice.offset, slice.length));
+            }
+
+            if (buffers.size() == 1) {
+                return buffers.get(0);
+            } else {
+                CompositeByteBuf composite = Unpooled.compositeBuffer(buffers.size());
+                composite.addComponents(true, buffers);
+                return composite;
+            }
+        } catch (IOException ex) {
+            throw new AssertionError("no IO happens here", ex);
+        }
+    }
+
+    /**
+     * Wraps the given ChannelBuffer with a BytesReference
+     * @param buffer buffer to convert
+     */
+    public static BytesReference toBytesReference(final ByteBuf buffer) {
+        final int readableBytes = buffer.readableBytes();
+        if (readableBytes == 0) {
+            return BytesArray.EMPTY;
+        } else if (buffer.hasArray()) {
+            return new BytesArray(buffer.array(), buffer.arrayOffset() + buffer.readerIndex(), readableBytes);
+        } else {
+            final ByteBuffer[] byteBuffers = buffer.nioBuffers();
+            return BytesReference.fromByteBuffers(byteBuffers);
+        }
+    }
+
+    /**
+     * Add completion listener to ChannelFuture
+     * @param channelFuture ChannelFuture to add listener to
+     * @param context completion listener context
+     */
+    public static void addListener(ChannelFuture channelFuture, CompletableContext<Void> context) {
+        channelFuture.addListener(f -> {
+            if (f.isSuccess()) {
+                context.complete(null);
+            } else {
+                Throwable cause = f.cause();
+                if (cause instanceof Error) {
+                    ExceptionsHelper.maybeDieOnAnotherThread(cause);
+                    context.completeExceptionally(new Exception(cause));
+                } else {
+                    context.completeExceptionally((Exception) cause);
+                }
+            }
+        });
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java
new file mode 100644
index 0000000000000..b3e92f58c540a
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/ReactorNetty4Transport.java
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.transport.reactor.netty4;
+
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Setting.Property;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+
+import reactor.netty.tcp.TcpServer;
+
+/**
+ * The transport implementations based on Reactor Netty (see please {@link TcpServer}).
+ */
+public class ReactorNetty4Transport {
+    /**
+     * The number of Netty workers
+     */
+    public static final Setting<Integer> SETTING_WORKER_COUNT = new Setting<>(
+        "transport.netty.worker_count",
+        (s) -> Integer.toString(OpenSearchExecutors.allocatedProcessors(s)),
+        (s) -> Setting.parseInt(s, 1, "transport.netty.worker_count"),
+        Property.NodeScope
+    );
+
+    /**
+     * Default constructor
+     */
+    public ReactorNetty4Transport() {}
+}
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java
new file mode 100644
index 0000000000000..921bca104c6fe
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/netty4/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * The new transport implementations based on Reactor Netty.
+ */
+package org.opensearch.transport.reactor.netty4;
diff --git a/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java
new file mode 100644
index 0000000000000..2f36ebb7f11f8
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/java/org/opensearch/transport/reactor/package-info.java
@@ -0,0 +1,12 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/**
+ * The experimental network plugin that introduces new transport implementations based on Reactor Netty.
+ */
+package org.opensearch.transport.reactor;
diff --git a/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy b/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy
new file mode 100644
index 0000000000000..4f2dcde995338
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/main/plugin-metadata/plugin-security.policy
@@ -0,0 +1,24 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+grant codeBase "${codebase.netty-common}" {
+   // for reading the system-wide configuration for the backlog of established sockets
+   permission java.io.FilePermission "/proc/sys/net/core/somaxconn", "read";
+
+   // netty makes and accepts socket connections
+   permission java.net.SocketPermission "*", "accept,connect";
+
+   // Netty sets custom classloader for some of its internal threads
+   permission java.lang.RuntimePermission "*", "setContextClassLoader";
+};
+
+grant codeBase "${codebase.netty-transport}" {
+   // Netty NioEventLoop wants to change this, because of https://bugs.openjdk.java.net/browse/JDK-6427854
+   // the bug says it only happened rarely, and that its fixed, but apparently it still happens rarely!
+   permission java.util.PropertyPermission "sun.nio.ch.bugLevel", "write";
+};
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java
new file mode 100644
index 0000000000000..443ecd0f40ead
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorHttpClient.java
@@ -0,0 +1,208 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.tasks.Task;
+
+import java.io.Closeable;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.EmptyHttpHeaders;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.HttpConversionUtil;
+import io.netty.resolver.DefaultAddressResolverGroup;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.publisher.ParallelFlux;
+import reactor.netty.http.client.HttpClient;
+
+import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+/**
+ * Tiny helper to send http requests over netty.
+ */
+class ReactorHttpClient implements Closeable {
+    private final boolean compression;
+
+    static Collection<String> returnHttpResponseBodies(Collection<FullHttpResponse> responses) {
+        List<String> list = new ArrayList<>(responses.size());
+        for (FullHttpResponse response : responses) {
+            list.add(response.content().toString(StandardCharsets.UTF_8));
+        }
+        return list;
+    }
+
+    static Collection<String> returnOpaqueIds(Collection<FullHttpResponse> responses) {
+        List<String> list = new ArrayList<>(responses.size());
+        for (HttpResponse response : responses) {
+            list.add(response.headers().get(Task.X_OPAQUE_ID));
+        }
+        return list;
+    }
+
+    ReactorHttpClient(boolean compression) {
+        this.compression = compression;
+    }
+
+    static ReactorHttpClient create() {
+        return create(true);
+    }
+
+    static ReactorHttpClient create(boolean compression) {
+        return new ReactorHttpClient(compression);
+    }
+
+    public List<FullHttpResponse> get(InetSocketAddress remoteAddress, String... uris) throws InterruptedException {
+        return get(remoteAddress, false, uris);
+    }
+
+    public List<FullHttpResponse> get(InetSocketAddress remoteAddress, boolean ordered, String... uris) throws InterruptedException {
+        final List<FullHttpRequest> requests = new ArrayList<>(uris.length);
+
+        for (int i = 0; i < uris.length; i++) {
+            final FullHttpRequest httpRequest = new DefaultFullHttpRequest(HTTP_1_1, HttpMethod.GET, uris[i]);
+            httpRequest.headers().add(HOST, "localhost");
+            httpRequest.headers().add("X-Opaque-ID", String.valueOf(i));
+            httpRequest.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), "http");
+            requests.add(httpRequest);
+        }
+
+        return sendRequests(remoteAddress, requests, ordered);
+    }
+
+    public final Collection<FullHttpResponse> post(InetSocketAddress remoteAddress, List<Tuple<String, CharSequence>> urisAndBodies)
+        throws InterruptedException {
+        return processRequestsWithBody(HttpMethod.POST, remoteAddress, urisAndBodies);
+    }
+
+    public final FullHttpResponse send(InetSocketAddress remoteAddress, FullHttpRequest httpRequest) throws InterruptedException {
+        final List<FullHttpResponse> responses = sendRequests(remoteAddress, Collections.singleton(httpRequest), false);
+        assert responses.size() == 1 : "expected 1 and only 1 http response";
+        return responses.get(0);
+    }
+
+    public final FullHttpResponse send(InetSocketAddress remoteAddress, FullHttpRequest httpRequest, HttpContent content)
+        throws InterruptedException {
+        final List<FullHttpResponse> responses = sendRequests(
+            remoteAddress,
+            Collections.singleton(
+                new DefaultFullHttpRequest(
+                    httpRequest.protocolVersion(),
+                    httpRequest.method(),
+                    httpRequest.uri(),
+                    content.content(),
+                    httpRequest.headers(),
+                    httpRequest.trailingHeaders()
+                )
+            ),
+            false
+        );
+        assert responses.size() == 1 : "expected 1 and only 1 http response";
+        return responses.get(0);
+    }
+
+    public final Collection<FullHttpResponse> put(InetSocketAddress remoteAddress, List<Tuple<String, CharSequence>> urisAndBodies)
+        throws InterruptedException {
+        return processRequestsWithBody(HttpMethod.PUT, remoteAddress, urisAndBodies);
+    }
+
+    private List<FullHttpResponse> processRequestsWithBody(
+        HttpMethod method,
+        InetSocketAddress remoteAddress,
+        List<Tuple<String, CharSequence>> urisAndBodies
+    ) throws InterruptedException {
+        List<FullHttpRequest> requests = new ArrayList<>(urisAndBodies.size());
+        for (int i = 0; i < urisAndBodies.size(); ++i) {
+            final Tuple<String, CharSequence> uriAndBody = urisAndBodies.get(i);
+            ByteBuf content = Unpooled.copiedBuffer(uriAndBody.v2(), StandardCharsets.UTF_8);
+            FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, method, uriAndBody.v1(), content);
+            request.headers().add(HttpHeaderNames.HOST, "localhost");
+            request.headers().add(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
+            request.headers().add(HttpHeaderNames.CONTENT_TYPE, "application/json");
+            request.headers().add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), "http");
+            request.headers().add("X-Opaque-ID", String.valueOf(i));
+            requests.add(request);
+        }
+        return sendRequests(remoteAddress, requests, false);
+    }
+
+    private List<FullHttpResponse> sendRequests(
+        final InetSocketAddress remoteAddress,
+        final Collection<FullHttpRequest> requests,
+        boolean orderer
+    ) {
+        final NioEventLoopGroup eventLoopGroup = new NioEventLoopGroup(1);
+        try {
+            final HttpClient client = HttpClient.newConnection()
+                .resolver(DefaultAddressResolverGroup.INSTANCE)
+                .runOn(eventLoopGroup)
+                .host(remoteAddress.getHostString())
+                .port(remoteAddress.getPort())
+                .compress(compression);
+
+            @SuppressWarnings("unchecked")
+            final Mono<FullHttpResponse>[] monos = requests.stream()
+                .map(
+                    request -> client.headers(h -> h.add(request.headers()))
+                        .baseUrl(request.getUri())
+                        .request(request.method())
+                        .send(Mono.fromSupplier(() -> request.content()))
+                        .responseSingle(
+                            (r, body) -> body.switchIfEmpty(Mono.just(Unpooled.EMPTY_BUFFER))
+                                .map(
+                                    b -> new DefaultFullHttpResponse(
+                                        r.version(),
+                                        r.status(),
+                                        b.retain(),
+                                        r.responseHeaders(),
+                                        EmptyHttpHeaders.INSTANCE
+                                    )
+                                )
+                        )
+                )
+                .toArray(Mono[]::new);
+
+            if (orderer == false) {
+                return ParallelFlux.from(monos).sequential().collectList().block();
+            } else {
+                return Flux.concat(monos).flatMapSequential(r -> Mono.just(r)).collectList().block();
+            }
+        } finally {
+            eventLoopGroup.shutdownGracefully().awaitUninterruptibly();
+        }
+    }
+
+    @Override
+    public void close() {
+
+    }
+}
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java
new file mode 100644
index 0000000000000..00ca378a4e46b
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4BadRequestTests.java
@@ -0,0 +1,122 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.opensearch.OpenSearchException;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.MockBigArrays;
+import org.opensearch.common.util.MockPageCacheRecycler;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.core.rest.RestStatus;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.HttpTransportSettings;
+import org.opensearch.rest.BytesRestResponse;
+import org.opensearch.rest.RestChannel;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.util.ReferenceCounted;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
+
+public class ReactorNetty4BadRequestTests extends OpenSearchTestCase {
+
+    private NetworkService networkService;
+    private MockBigArrays bigArrays;
+    private ThreadPool threadPool;
+
+    @Before
+    public void setup() throws Exception {
+        networkService = new NetworkService(Collections.emptyList());
+        bigArrays = new MockBigArrays(new MockPageCacheRecycler(Settings.EMPTY), new NoneCircuitBreakerService());
+        threadPool = new TestThreadPool("test");
+    }
+
+    @After
+    public void shutdown() throws Exception {
+        terminate(threadPool);
+    }
+
+    public void testBadParameterEncoding() throws Exception {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(RestRequest request, RestChannel channel, ThreadContext threadContext) {
+                fail();
+            }
+
+            @Override
+            public void dispatchBadRequest(RestChannel channel, ThreadContext threadContext, Throwable cause) {
+                try {
+                    final Exception e = cause instanceof Exception ? (Exception) cause : new OpenSearchException(cause);
+                    channel.sendResponse(new BytesRestResponse(channel, RestStatus.BAD_REQUEST, e));
+                } catch (final IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            }
+        };
+
+        Settings settings = Settings.builder().put(HttpTransportSettings.SETTING_HTTP_PORT.getKey(), getPortRange()).build();
+        try (
+            HttpServerTransport httpServerTransport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            httpServerTransport.start();
+            final TransportAddress transportAddress = randomFrom(httpServerTransport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient nettyHttpClient = ReactorHttpClient.create()) {
+                final List<FullHttpResponse> responses = nettyHttpClient.get(transportAddress.address(), "/_cluster/settings?pretty=%");
+
+                try {
+                    assertThat(responses, hasSize(1));
+                    final FullHttpResponse response = responses.get(0);
+                    assertThat(response.status().code(), equalTo(400));
+                    final Collection<String> responseBodies = ReactorHttpClient.returnHttpResponseBodies(responses);
+                    assertThat(responseBodies, hasSize(1));
+                    final String body = responseBodies.iterator().next();
+                    assertThat(body, containsString("\"type\":\"bad_parameter_exception\""));
+                    assertThat(
+                        body,
+                        containsString("\"reason\":\"java.lang.IllegalArgumentException: partial escape sequence at end of string: %/\"")
+                    );
+                } finally {
+                    responses.forEach(ReferenceCounted::release);
+                }
+            }
+        }
+    }
+
+}
diff --git a/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java
new file mode 100644
index 0000000000000..15a5b04c802a4
--- /dev/null
+++ b/plugins/transport-reactor-netty4/src/test/java/org/opensearch/http/reactor/netty4/ReactorNetty4HttpServerTransportTests.java
@@ -0,0 +1,579 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.http.reactor.netty4;
+
+import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.network.NetworkAddress;
+import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.ClusterSettings;
+import org.opensearch.common.settings.Setting;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.MockBigArrays;
+import org.opensearch.common.util.MockPageCacheRecycler;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.bytes.BytesArray;
+import org.opensearch.core.common.transport.TransportAddress;
+import org.opensearch.core.common.unit.ByteSizeValue;
+import org.opensearch.core.indices.breaker.NoneCircuitBreakerService;
+import org.opensearch.http.BindHttpException;
+import org.opensearch.http.CorsHandler;
+import org.opensearch.http.HttpServerTransport;
+import org.opensearch.http.HttpTransportSettings;
+import org.opensearch.http.NullDispatcher;
+import org.opensearch.rest.BytesRestResponse;
+import org.opensearch.rest.RestChannel;
+import org.opensearch.rest.RestRequest;
+import org.opensearch.telemetry.tracing.noop.NoopTracer;
+import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.test.rest.FakeRestRequest;
+import org.opensearch.threadpool.TestThreadPool;
+import org.opensearch.threadpool.ThreadPool;
+import org.opensearch.transport.NettyAllocator;
+import org.opensearch.transport.reactor.SharedGroupFactory;
+import org.junit.After;
+import org.junit.Before;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.ByteBufAllocator;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.PoolArenaMetric;
+import io.netty.buffer.PooledByteBufAllocator;
+import io.netty.buffer.PooledByteBufAllocatorMetric;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerAdapter;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.DefaultHttpContent;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http.HttpUtil;
+import io.netty.handler.codec.http.HttpVersion;
+
+import static org.opensearch.core.rest.RestStatus.OK;
+import static org.opensearch.http.HttpTransportSettings.SETTING_CORS_ALLOW_ORIGIN;
+import static org.opensearch.http.HttpTransportSettings.SETTING_CORS_ENABLED;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Tests for the {@link ReactorNetty4HttpServerTransport} class.
+ */
+public class ReactorNetty4HttpServerTransportTests extends OpenSearchTestCase {
+
+    private NetworkService networkService;
+    private ThreadPool threadPool;
+    private MockBigArrays bigArrays;
+    private ClusterSettings clusterSettings;
+
+    @Before
+    public void setup() throws Exception {
+        networkService = new NetworkService(Collections.emptyList());
+        threadPool = new TestThreadPool("test");
+        bigArrays = new MockBigArrays(new MockPageCacheRecycler(Settings.EMPTY), new NoneCircuitBreakerService());
+        clusterSettings = new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
+    }
+
+    @After
+    public void shutdown() throws Exception {
+        if (threadPool != null) {
+            threadPool.shutdownNow();
+        }
+        threadPool = null;
+        networkService = null;
+        bigArrays = null;
+        clusterSettings = null;
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} supports the "Expect: 100-continue" HTTP header
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectContinueHeader() throws InterruptedException {
+        final Settings settings = createSettings();
+        final int contentLength = randomIntBetween(1, HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH.get(settings).bytesAsInt());
+        runExpectHeaderTest(settings, HttpHeaderValues.CONTINUE.toString(), contentLength, HttpResponseStatus.CONTINUE);
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} responds to a
+     * 100-continue expectation with too large a content-length
+     * with a 413 status.
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectContinueHeaderContentLengthTooLong() throws InterruptedException {
+        final String key = HttpTransportSettings.SETTING_HTTP_MAX_CONTENT_LENGTH.getKey();
+        final int maxContentLength = randomIntBetween(1, 104857600);
+        final Settings settings = createBuilderWithPort().put(key, maxContentLength + "b").build();
+        final int contentLength = randomIntBetween(maxContentLength + 1, Integer.MAX_VALUE);
+        runExpectHeaderTest(settings, HttpHeaderValues.CONTINUE.toString(), contentLength, HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE);
+    }
+
+    /**
+     * Test that {@link ReactorNetty4HttpServerTransport} responds to an unsupported expectation with a 417 status.
+     * @throws InterruptedException if the client communication with the server is interrupted
+     */
+    public void testExpectUnsupportedExpectation() throws InterruptedException {
+        Settings settings = createSettings();
+        runExpectHeaderTest(settings, "chocolate=yummy", 0, HttpResponseStatus.EXPECTATION_FAILED);
+    }
+
+    private void runExpectHeaderTest(
+        final Settings settings,
+        final String expectation,
+        final int contentLength,
+        final HttpResponseStatus expectedStatus
+    ) throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(RestRequest request, RestChannel channel, ThreadContext threadContext) {
+                channel.sendResponse(new BytesRestResponse(OK, BytesRestResponse.TEXT_CONTENT_TYPE, new BytesArray("done")));
+            }
+
+            @Override
+            public void dispatchBadRequest(RestChannel channel, ThreadContext threadContext, Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+        };
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, "/");
+                request.headers().set(HttpHeaderNames.EXPECT, expectation);
+                HttpUtil.setContentLength(request, contentLength);
+
+                // Reactor Netty 4 does not expose 100 CONTINUE response but instead just asks for content
+                final HttpContent continuationRequest = new DefaultHttpContent(Unpooled.EMPTY_BUFFER);
+                final FullHttpResponse continuationResponse = client.send(remoteAddress.address(), request, continuationRequest);
+                try {
+                    assertThat(continuationResponse.status(), is(HttpResponseStatus.OK));
+                    assertThat(new String(ByteBufUtil.getBytes(continuationResponse.content()), StandardCharsets.UTF_8), is("done"));
+                } finally {
+                    continuationResponse.release();
+                }
+            }
+        }
+    }
+
+    public void testBindUnavailableAddress() {
+        Settings initialSettings = createSettings();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                initialSettings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                new NullDispatcher(),
+                clusterSettings,
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+            Settings settings = Settings.builder()
+                .put("http.port", remoteAddress.getPort())
+                .put("network.host", remoteAddress.getAddress())
+                .build();
+            try (
+                ReactorNetty4HttpServerTransport otherTransport = new ReactorNetty4HttpServerTransport(
+                    settings,
+                    networkService,
+                    bigArrays,
+                    threadPool,
+                    xContentRegistry(),
+                    new NullDispatcher(),
+                    clusterSettings,
+                    new SharedGroupFactory(settings),
+                    NoopTracer.INSTANCE
+                )
+            ) {
+                BindHttpException bindHttpException = expectThrows(BindHttpException.class, otherTransport::start);
+                assertEquals("Failed to bind to " + NetworkAddress.format(remoteAddress.address()), bindHttpException.getMessage());
+            }
+        }
+    }
+
+    public void testBadRequest() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError();
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error("--> Unexpected bad request request");
+                throw new AssertionError(cause);
+            }
+        };
+
+        final Settings settings;
+        final int maxInitialLineLength;
+        final Setting<ByteSizeValue> httpMaxInitialLineLengthSetting = HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH;
+        if (randomBoolean()) {
+            maxInitialLineLength = httpMaxInitialLineLengthSetting.getDefault(Settings.EMPTY).bytesAsInt();
+            settings = createSettings();
+        } else {
+            maxInitialLineLength = randomIntBetween(1, 8192);
+            settings = createBuilderWithPort().put(httpMaxInitialLineLengthSetting.getKey(), maxInitialLineLength + "b").build();
+        }
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final String url = "/" + randomAlphaOfLength(maxInitialLineLength);
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, url);
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.REQUEST_URI_TOO_LONG));
+                    assertThat(response.content().array().length, equalTo(0));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testDispatchFailed() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                throw new RuntimeException("Bad things happen");
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error("--> Unexpected bad request request");
+                throw new AssertionError(cause);
+            }
+        };
+
+        final Settings settings = createSettings();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.INTERNAL_SERVER_ERROR));
+                    assertThat(response.content().array().length, equalTo(0));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testLargeCompressedResponse() throws InterruptedException {
+        final String responseString = randomAlphaOfLength(4 * 1024 * 1024);
+        final String url = "/thing/";
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                if (url.equals(request.uri())) {
+                    channel.sendResponse(new BytesRestResponse(OK, responseString));
+                } else {
+                    logger.error("--> Unexpected successful uri [{}]", request.uri());
+                    throw new AssertionError();
+                }
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+
+        };
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                Settings.EMPTY,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                clusterSettings,
+                new SharedGroupFactory(Settings.EMPTY),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                DefaultFullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, url);
+                request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, randomFrom("deflate", "gzip"));
+                long numOfHugeAllocations = getHugeAllocationCount();
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(getHugeAllocationCount(), equalTo(numOfHugeAllocations));
+                    assertThat(response.status(), equalTo(HttpResponseStatus.OK));
+                    byte[] bytes = new byte[response.content().readableBytes()];
+                    response.content().readBytes(bytes);
+                    assertThat(new String(bytes, StandardCharsets.UTF_8), equalTo(responseString));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    private long getHugeAllocationCount() {
+        long numOfHugAllocations = 0;
+        ByteBufAllocator allocator = NettyAllocator.getAllocator();
+        assert allocator instanceof NettyAllocator.NoDirectBuffers;
+        ByteBufAllocator delegate = ((NettyAllocator.NoDirectBuffers) allocator).getDelegate();
+        if (delegate instanceof PooledByteBufAllocator) {
+            PooledByteBufAllocatorMetric metric = ((PooledByteBufAllocator) delegate).metric();
+            numOfHugAllocations = metric.heapArenas().stream().mapToLong(PoolArenaMetric::numHugeAllocations).sum();
+        }
+        return numOfHugAllocations;
+    }
+
+    public void testCorsRequest() throws InterruptedException {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError();
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError();
+            }
+
+        };
+
+        final Settings settings = createBuilderWithPort().put(SETTING_CORS_ENABLED.getKey(), true)
+            .put(SETTING_CORS_ALLOW_ORIGIN.getKey(), "test-cors.org")
+            .build();
+
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            // Test pre-flight request
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.OPTIONS, "/");
+                request.headers().add(CorsHandler.ORIGIN, "test-cors.org");
+                request.headers().add(CorsHandler.ACCESS_CONTROL_REQUEST_METHOD, "POST");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.OK));
+                    assertThat(response.headers().get(CorsHandler.ACCESS_CONTROL_ALLOW_ORIGIN), equalTo("test-cors.org"));
+                    assertThat(response.headers().get(CorsHandler.VARY), equalTo(CorsHandler.ORIGIN));
+                    assertTrue(response.headers().contains(CorsHandler.DATE));
+                } finally {
+                    response.release();
+                }
+            }
+
+            // Test short-circuited request
+            try (ReactorHttpClient client = ReactorHttpClient.create()) {
+                final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+                request.headers().add(CorsHandler.ORIGIN, "google.com");
+
+                final FullHttpResponse response = client.send(remoteAddress.address(), request);
+                try {
+                    assertThat(response.status(), equalTo(HttpResponseStatus.FORBIDDEN));
+                } finally {
+                    response.release();
+                }
+            }
+        }
+    }
+
+    public void testConnectTimeout() throws Exception {
+        final HttpServerTransport.Dispatcher dispatcher = new HttpServerTransport.Dispatcher() {
+
+            @Override
+            public void dispatchRequest(final RestRequest request, final RestChannel channel, final ThreadContext threadContext) {
+                logger.error("--> Unexpected successful request [{}]", FakeRestRequest.requestToString(request));
+                throw new AssertionError("Should not have received a dispatched request");
+            }
+
+            @Override
+            public void dispatchBadRequest(final RestChannel channel, final ThreadContext threadContext, final Throwable cause) {
+                logger.error(
+                    new ParameterizedMessage("--> Unexpected bad request [{}]", FakeRestRequest.requestToString(channel.request())),
+                    cause
+                );
+                throw new AssertionError("Should not have received a dispatched request");
+            }
+
+        };
+
+        Settings settings = createBuilderWithPort().put(
+            HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT.getKey(),
+            new TimeValue(randomIntBetween(100, 300))
+        ).build();
+
+        NioEventLoopGroup group = new NioEventLoopGroup();
+        try (
+            ReactorNetty4HttpServerTransport transport = new ReactorNetty4HttpServerTransport(
+                settings,
+                networkService,
+                bigArrays,
+                threadPool,
+                xContentRegistry(),
+                dispatcher,
+                new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS),
+                new SharedGroupFactory(settings),
+                NoopTracer.INSTANCE
+            )
+        ) {
+            transport.start();
+            final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
+
+            final CountDownLatch channelClosedLatch = new CountDownLatch(1);
+
+            final Bootstrap clientBootstrap = new Bootstrap().option(ChannelOption.ALLOCATOR, NettyAllocator.getAllocator())
+                .channel(NioSocketChannel.class)
+                .handler(new ChannelInitializer<SocketChannel>() {
+
+                    @Override
+                    protected void initChannel(SocketChannel ch) {
+                        ch.pipeline().addLast(new ChannelHandlerAdapter() {
+                        });
+
+                    }
+                })
+                .group(group);
+            ChannelFuture connect = clientBootstrap.connect(remoteAddress.address());
+            connect.channel().closeFuture().addListener(future -> channelClosedLatch.countDown());
+
+            assertTrue("Channel should be closed due to read timeout", channelClosedLatch.await(1, TimeUnit.MINUTES));
+
+        } finally {
+            group.shutdownGracefully().await();
+        }
+    }
+
+    private Settings createSettings() {
+        return createBuilderWithPort().build();
+    }
+
+    private Settings.Builder createBuilderWithPort() {
+        return Settings.builder().put(HttpTransportSettings.SETTING_HTTP_PORT.getKey(), getPortRange());
+    }
+}
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..e669016cad98a
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/30_geoshape.yml
@@ -0,0 +1,16 @@
+---
+"Insert Document with geoshape field":
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..30a39447905c0
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/30_geoshape.yml
@@ -0,0 +1,28 @@
+---
+"Create index with Geoshape field":
+  - do:
+      indices.create:
+        index: geo_shape_index_old
+        body:
+          settings:
+            index:
+              number_of_replicas: 2
+          mappings:
+            "properties":
+              "location":
+                "type": "geo_shape"
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml
new file mode 100644
index 0000000000000..4c7b12a7f1909
--- /dev/null
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/30_geoshape.yml
@@ -0,0 +1,61 @@
+---
+"Validate we are able to index documents after upgrade":
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_old", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_old", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_old
+  - match: { hits.total: 2 }
+
+
+---
+"Create index with Geoshape field in new cluster":
+  - do:
+      indices.create:
+        index: geo_shape_index_new
+        body:
+          settings:
+            index:
+              number_of_replicas: 2
+          mappings:
+            "properties":
+              "location":
+                "type": "geo_shape"
+
+  - do:
+      bulk:
+        refresh: true
+        body:
+          - '{"index": {"_index": "geo_shape_index_new", "_id":191}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [101.0, 0.0] ]}}'
+          - '{"index": {"_index": "geo_shape_index_new", "_id":219}}'
+          - '{"name": "NEMO Science Museum","location": {"type": "envelope","coordinates": [ [100.0, 1.0], [106.0, 0.0] ]}}'
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_new
+  - match: { hits.total: 2 }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        index: geo_shape_index_new
+        body:
+          aggregations:
+            myaggregation:
+              geo_bounds:
+                field: "location"
+  - match: { hits.total: 2 }
+  - match: { aggregations.myaggregation.bounds.top_left.lat: 0.9999999823048711 }
+  - match: { aggregations.myaggregation.bounds.top_left.lon: 99.99999999068677 }
+  - match: { aggregations.myaggregation.bounds.bottom_right.lat: 0.0 }
+  - match: { aggregations.myaggregation.bounds.bottom_right.lon: 105.99999996833503 }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml
new file mode 100644
index 0000000000000..8829e7b100fdd
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/340_keyword_doc_values.yml
@@ -0,0 +1,46 @@
+---
+"search on keyword fields with doc_values enabled":
+  - do:
+      indices.create:
+        index: test
+        body:
+          mappings:
+            properties:
+              "some_keyword":
+                type: "keyword"
+                index: true
+                doc_values: true
+
+  - do:
+      bulk:
+        index: test
+        refresh: true
+        body:
+          - '{"index": {"_index": "test", "_id": "1" }}'
+          - '{ "some_keyword": "ingesting some random keyword data" }'
+          - '{ "index": { "_index": "test", "_id": "2" }}'
+          - '{ "some_keyword": "400" }'
+          - '{ "index": { "_index": "test", "_id": "3" } }'
+          - '{ "some_keyword": "5" }'
+
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            prefix:
+              some_keyword: "ing"
+
+  - match: { hits.hits.0._source.some_keyword: "ingesting some random keyword data" }
+
+  - do:
+      search:
+        index: test
+        body:
+          query:
+            range: {
+              "some_keyword": {
+                "lt": 500
+              } }
+
+  - match: { hits.total.value: 2 }
diff --git a/server/build.gradle b/server/build.gradle
index c56f9d5aa288f..fa8a44ef6fc94 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -154,6 +154,10 @@ dependencies {
   // jcraft
   api "com.jcraft:jzlib:${versions.jzlib}"
 
+  // reactor
+  api "io.projectreactor:reactor-core:${versions.reactor}"
+  api "org.reactivestreams:reactive-streams:${versions.reactivestreams}"
+
   // protobuf
   api "com.google.protobuf:protobuf-java:${versions.protobuf}"
   api "jakarta.annotation:jakarta.annotation-api:${versions.jakarta_annotation}"
@@ -366,11 +370,13 @@ tasks.named("thirdPartyAudit").configure {
             'com.google.protobuf.UnsafeUtil$JvmMemoryAccessor',
             'com.google.protobuf.UnsafeUtil$MemoryAccessor',
             'org.apache.logging.log4j.core.util.internal.UnsafeUtil',
-            'org.apache.logging.log4j.core.util.internal.UnsafeUtil$1'
+            'org.apache.logging.log4j.core.util.internal.UnsafeUtil$1',
+            'reactor.core.publisher.Traces$SharedSecretsCallSiteSupplierFactory$TracingException'
     )
 }
 
 tasks.named("dependencyLicenses").configure {
+    mapping from: /reactor-.*/, to: 'reactor'
     mapping from: /lucene-.*/, to: 'lucene'
     dependencies = project.configurations.runtimeClasspath.fileCollection {
         it.group.startsWith('org.opensearch') == false ||
diff --git a/plugins/crypto-kms/licenses/reactive-streams-1.0.4.jar.sha1 b/server/licenses/reactive-streams-1.0.4.jar.sha1
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-1.0.4.jar.sha1
rename to server/licenses/reactive-streams-1.0.4.jar.sha1
diff --git a/plugins/crypto-kms/licenses/reactive-streams-LICENSE.txt b/server/licenses/reactive-streams-LICENSE.txt
similarity index 100%
rename from plugins/crypto-kms/licenses/reactive-streams-LICENSE.txt
rename to server/licenses/reactive-streams-LICENSE.txt
diff --git a/plugins/discovery-ec2/licenses/reactive-streams-NOTICE.txt b/server/licenses/reactive-streams-NOTICE.txt
similarity index 100%
rename from plugins/discovery-ec2/licenses/reactive-streams-NOTICE.txt
rename to server/licenses/reactive-streams-NOTICE.txt
diff --git a/server/licenses/reactor-LICENSE.txt b/server/licenses/reactor-LICENSE.txt
new file mode 100644
index 0000000000000..e5583c184e67a
--- /dev/null
+++ b/server/licenses/reactor-LICENSE.txt
@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/plugins/repository-azure/licenses/reactive-streams-NOTICE.txt b/server/licenses/reactor-NOTICE.txt
similarity index 100%
rename from plugins/repository-azure/licenses/reactive-streams-NOTICE.txt
rename to server/licenses/reactor-NOTICE.txt
diff --git a/server/licenses/reactor-core-3.5.11.jar.sha1 b/server/licenses/reactor-core-3.5.11.jar.sha1
new file mode 100644
index 0000000000000..e5ffdbc8a7840
--- /dev/null
+++ b/server/licenses/reactor-core-3.5.11.jar.sha1
@@ -0,0 +1 @@
+db2299757f562261eb775d13658e86ff06f91e8a
\ No newline at end of file
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java
new file mode 100644
index 0000000000000..a081110e6c5a1
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteCloneIndexIT.java
@@ -0,0 +1,133 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+import org.opensearch.Version;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.shrink.ResizeType;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.hamcrest.Matchers.equalTo;
+
+public class RemoteCloneIndexIT extends RemoteStoreBaseIntegTestCase {
+
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public void testCreateCloneIndex() {
+        Version version = VersionUtils.randomIndexCompatibleVersion(random());
+        int numPrimaryShards = randomIntBetween(1, 5);
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", numPrimaryShards).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+        try {
+            assertAcked(
+                client().admin()
+                    .indices()
+                    .prepareResizeIndex("source", "target")
+                    .setResizeType(ResizeType.CLONE)
+                    .setSettings(Settings.builder().put("index.number_of_replicas", 0).putNull("index.blocks.write").build())
+                    .get()
+            );
+            ensureGreen();
+
+            final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+            assertThat(targetStats.getIndex("target").getIndexShards().keySet().size(), equalTo(numPrimaryShards));
+
+            final int size = docs > 0 ? 2 * docs : 1;
+            assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+            for (int i = docs; i < 2 * docs; i++) {
+                client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+            }
+            flushAndRefresh();
+            assertHitCount(
+                client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+                2 * docs
+            );
+            assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+            GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+            assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+        } finally {
+            // clean up
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setTransientSettings(
+                    Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+                )
+                .get();
+        }
+
+    }
+
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java
new file mode 100644
index 0000000000000..282eb9c6ad95e
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteShrinkIndexIT.java
@@ -0,0 +1,545 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+import org.apache.lucene.search.Sort;
+import org.apache.lucene.search.SortField;
+import org.apache.lucene.search.SortedSetSelector;
+import org.apache.lucene.search.SortedSetSortField;
+import org.apache.lucene.util.Constants;
+import org.opensearch.Version;
+import org.opensearch.action.admin.cluster.reroute.ClusterRerouteResponse;
+import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.support.ActiveShardCount;
+import org.opensearch.client.Client;
+import org.opensearch.cluster.ClusterInfoService;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.InternalClusterInfoService;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.routing.Murmur3HashFunction;
+import org.opensearch.cluster.routing.RoutingTable;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.UnassignedInfo;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.Priority;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.IndexModule;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.engine.SegmentsStats;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.index.seqno.SeqNoStats;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.IntStream;
+
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+
+public class RemoteShrinkIndexIT extends RemoteStoreBaseIntegTestCase {
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public Settings indexSettings() {
+        return Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(SETTING_NUMBER_OF_REPLICAS, 0)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .build();
+    }
+
+    public void testCreateShrinkIndexToN() {
+
+        assumeFalse("https://github.com/elastic/elasticsearch/issues/34080", Constants.WINDOWS);
+
+        int[][] possibleShardSplits = new int[][] { { 8, 4, 2 }, { 9, 3, 1 }, { 4, 2, 1 }, { 15, 5, 1 } };
+        int[] shardSplits = randomFrom(possibleShardSplits);
+        assertEquals(shardSplits[0], (shardSplits[0] / shardSplits[1]) * shardSplits[1]);
+        assertEquals(shardSplits[1], (shardSplits[1] / shardSplits[2]) * shardSplits[2]);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(Settings.builder().put(indexSettings()).put("number_of_shards", shardSplits[0])).get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String mergeNode = discoveryNodes[0].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now merge source into a 4 shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "first_shrink")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", shardSplits[1])
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        for (int i = 0; i < 20; i++) { // now update
+            client().prepareIndex("first_shrink")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("first_shrink")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now merge source into a 2 shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("first_shrink", "second_shrink")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", shardSplits[2])
+                        .putNull("index.blocks.write")
+                        .putNull("index.routing.allocation.require._name")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        // let it be allocated anywhere and bump replicas
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("second_shrink")
+            .setSettings(Settings.builder().putNull("index.routing.allocation.include._id").put("index.number_of_replicas", 0))
+            .get();
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+
+        for (int i = 0; i < 20; i++) { // now update
+            client().prepareIndex("second_shrink")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("second_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("first_shrink").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+    }
+
+    public void testShrinkIndexPrimaryTerm() throws Exception {
+        int numberOfShards = randomIntBetween(2, 20);
+        int numberOfTargetShards = randomValueOtherThanMany(n -> numberOfShards % n != 0, () -> randomIntBetween(1, numberOfShards - 1));
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(Settings.builder().put(indexSettings()).put("number_of_shards", numberOfShards)).get();
+
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertThat(dataNodes.size(), greaterThanOrEqualTo(2));
+        final DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        final String mergeNode = discoveryNodes[0].getName();
+        // This needs more than the default timeout if a large number of shards were created.
+        ensureGreen(TimeValue.timeValueSeconds(120));
+
+        // fail random primary shards to force primary terms to increase
+        final Index source = resolveIndex("source");
+        final int iterations = scaledRandomIntBetween(0, 16);
+        for (int i = 0; i < iterations; i++) {
+            final String node = randomSubsetOf(1, internalCluster().nodesInclude("source")).get(0);
+            final IndicesService indexServices = internalCluster().getInstance(IndicesService.class, node);
+            final IndexService indexShards = indexServices.indexServiceSafe(source);
+            for (final Integer shardId : indexShards.shardIds()) {
+                final IndexShard shard = indexShards.getShard(shardId);
+                if (shard.routingEntry().primary() && randomBoolean()) {
+                    disableAllocation("source");
+                    shard.failShard("test", new Exception("test"));
+                    // this can not succeed until the shard is failed and a replica is promoted
+                    int id = 0;
+                    while (true) {
+                        // find an ID that routes to the right shard, we will only index to the shard that saw a primary failure
+                        final String s = Integer.toString(id);
+                        final int hash = Math.floorMod(Murmur3HashFunction.hash(s), numberOfShards);
+                        if (hash == shardId) {
+                            final IndexRequest request = new IndexRequest("source").id(s)
+                                .source("{ \"f\": \"" + s + "\"}", MediaTypeRegistry.JSON);
+                            client().index(request).get();
+                            break;
+                        } else {
+                            id++;
+                        }
+                    }
+                    enableAllocation("source");
+                    ensureGreen();
+                }
+            }
+        }
+
+        // relocate all shards to one node such that we can merge it.
+        final Settings.Builder prepareShrinkSettings = Settings.builder()
+            .put("index.routing.allocation.require._name", mergeNode)
+            .put("index.blocks.write", true);
+        client().admin().indices().prepareUpdateSettings("source").setSettings(prepareShrinkSettings).get();
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to relocate many shards
+
+        final IndexMetadata indexMetadata = indexMetadata(client(), "source");
+        final long beforeShrinkPrimaryTerm = IntStream.range(0, numberOfShards).mapToLong(indexMetadata::primaryTerm).max().getAsLong();
+
+        // now merge source into target
+        final Settings shrinkSettings = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", numberOfTargetShards)
+            .build();
+        assertAcked(client().admin().indices().prepareResizeIndex("source", "target").setSettings(shrinkSettings).get());
+
+        ensureGreen(TimeValue.timeValueSeconds(120));
+
+        final IndexMetadata afterShrinkIndexMetadata = indexMetadata(client(), "target");
+        for (int shardId = 0; shardId < numberOfTargetShards; shardId++) {
+            assertThat(afterShrinkIndexMetadata.primaryTerm(shardId), equalTo(beforeShrinkPrimaryTerm + 1));
+        }
+    }
+
+    private static IndexMetadata indexMetadata(final Client client, final String index) {
+        final ClusterStateResponse clusterStateResponse = client.admin().cluster().state(new ClusterStateRequest()).actionGet();
+        return clusterStateResponse.getState().metadata().index(index);
+    }
+
+    public void testCreateShrinkIndex() {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        Version version = VersionUtils.randomVersion(random());
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", randomIntBetween(2, 7)).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(
+                Settings.builder()
+                    .put("index.routing.allocation.require._name", discoveryNodes[0].getName())
+                    .put("index.blocks.write", true)
+            )
+            .get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+
+        // now merge source into a single shard index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .putNull("index.blocks.write")
+                        .putNull("index.routing.allocation.require._name")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+
+        // resolve true merge node - this is not always the node we required as all shards may be on another node
+        final ClusterState state = client().admin().cluster().prepareState().get().getState();
+        DiscoveryNode mergeNode = state.nodes().get(state.getRoutingTable().index("target").shard(0).primaryShard().currentNodeId());
+        logger.info("merge node {}", mergeNode);
+
+        final long maxSeqNo = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getSeqNoStats)
+            .mapToLong(SeqNoStats::getMaxSeqNo)
+            .max()
+            .getAsLong();
+        final long maxUnsafeAutoIdTimestamp = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getStats)
+            .map(CommonStats::getSegments)
+            .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
+            .max()
+            .getAsLong();
+
+        final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+        for (final ShardStats shardStats : targetStats.getShards()) {
+            final SeqNoStats seqNoStats = shardStats.getSeqNoStats();
+            final ShardRouting shardRouting = shardStats.getShardRouting();
+            assertThat("failed on " + shardRouting, seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
+            assertThat("failed on " + shardRouting, seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+            assertThat(
+                "failed on " + shardRouting,
+                shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(),
+                equalTo(maxUnsafeAutoIdTimestamp)
+            );
+        }
+
+        final int size = docs > 0 ? 2 * docs : 1;
+        assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+        for (int i = docs; i < 2 * docs; i++) {
+            client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 2 * docs);
+        assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+        GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+        assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+
+        // clean up
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+            )
+            .get();
+    }
+
+    /**
+     * Tests that we can manually recover from a failed allocation due to shards being moved away etc.
+     */
+    public void testCreateShrinkIndexFails() throws Exception {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", randomIntBetween(2, 7)).put("number_of_replicas", 0)
+        ).get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String spareNode = discoveryNodes[0].getName();
+        String mergeNode = discoveryNodes[1].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+
+        // now merge source into a single shard index
+        client().admin()
+            .indices()
+            .prepareResizeIndex("source", "target")
+            .setWaitForActiveShards(ActiveShardCount.NONE)
+            .setSettings(
+                Settings.builder()
+                    .put("index.routing.allocation.exclude._name", mergeNode) // we manually exclude the merge node to forcefully fuck it up
+                    .put("index.number_of_replicas", 0)
+                    .put("index.allocation.max_retries", 1)
+                    .build()
+            )
+            .get();
+        client().admin().cluster().prepareHealth("target").setWaitForEvents(Priority.LANGUID).get();
+
+        // now we move all shards away from the merge node
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", spareNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen("source");
+
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("target") // erase the forcefully fuckup!
+            .setSettings(Settings.builder().putNull("index.routing.allocation.exclude._name"))
+            .get();
+        // wait until it fails
+        assertBusy(() -> {
+            ClusterStateResponse clusterStateResponse = client().admin().cluster().prepareState().get();
+            RoutingTable routingTables = clusterStateResponse.getState().routingTable();
+            assertTrue(routingTables.index("target").shard(0).getShards().get(0).unassigned());
+            assertEquals(
+                UnassignedInfo.Reason.ALLOCATION_FAILED,
+                routingTables.index("target").shard(0).getShards().get(0).unassignedInfo().getReason()
+            );
+            assertEquals(1, routingTables.index("target").shard(0).getShards().get(0).unassignedInfo().getNumFailedAllocations());
+        });
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source") // now relocate them all to the right node
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode))
+            .get();
+        ensureGreen("source");
+
+        final InternalClusterInfoService infoService = (InternalClusterInfoService) internalCluster().getInstance(
+            ClusterInfoService.class,
+            internalCluster().getClusterManagerName()
+        );
+        infoService.refresh();
+        // kick off a retry and wait until it's done!
+        ClusterRerouteResponse clusterRerouteResponse = client().admin().cluster().prepareReroute().setRetryFailed(true).get();
+        long expectedShardSize = clusterRerouteResponse.getState()
+            .routingTable()
+            .index("target")
+            .shard(0)
+            .getShards()
+            .get(0)
+            .getExpectedShardSize();
+        // we support the expected shard size in the allocator to sum up over the source index shards
+        assertTrue("expected shard size must be set but wasn't: " + expectedShardSize, expectedShardSize > 0);
+        ensureGreen();
+        assertHitCount(client().prepareSearch("target").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), 20);
+    }
+
+    public void testCreateShrinkWithIndexSort() throws Exception {
+        SortField expectedSortField = new SortedSetSortField("id", true, SortedSetSelector.Type.MAX);
+        expectedSortField.setMissingValue(SortedSetSortField.STRING_FIRST);
+        Sort expectedIndexSort = new Sort(expectedSortField);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder()
+                .put(indexSettings())
+                .put("sort.field", "id")
+                .put("sort.order", "desc")
+                .put("number_of_shards", 8)
+                .put("number_of_replicas", 0)
+        ).setMapping("id", "type=keyword,doc_values=true").get();
+        for (int i = 0; i < 20; i++) {
+            client().prepareIndex("source")
+                .setId(Integer.toString(i))
+                .setSource("{\"foo\" : \"bar\", \"id\" : " + i + "}", MediaTypeRegistry.JSON)
+                .get();
+        }
+        final Map<String, DiscoveryNode> dataNodes = client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
+        assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
+        DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(new DiscoveryNode[0]);
+        String mergeNode = discoveryNodes[0].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+
+        flushAndRefresh();
+        assertSortedSegments("source", expectedIndexSort);
+
+        // relocate all shards to one node such that we can merge it.
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("source")
+            .setSettings(Settings.builder().put("index.routing.allocation.require._name", mergeNode).put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+
+        // check that index sort cannot be set on the target index
+        IllegalArgumentException exc = expectThrows(
+            IllegalArgumentException.class,
+            () -> client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", "2")
+                        .put("index.sort.field", "foo")
+                        .build()
+                )
+                .get()
+        );
+        assertThat(exc.getMessage(), containsString("can't override index sort when resizing an index"));
+
+        // check that the index sort order of `source` is correctly applied to the `target`
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", "2")
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        flushAndRefresh();
+        GetSettingsResponse settingsResponse = client().admin().indices().prepareGetSettings("target").execute().actionGet();
+        assertEquals(settingsResponse.getSetting("target", "index.sort.field"), "id");
+        assertEquals(settingsResponse.getSetting("target", "index.sort.order"), "desc");
+        assertSortedSegments("target", expectedIndexSort);
+
+        // ... and that the index sort is also applied to updates
+        for (int i = 20; i < 40; i++) {
+            client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        flushAndRefresh();
+        assertSortedSegments("target", expectedIndexSort);
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java
new file mode 100644
index 0000000000000..dd4252d24f314
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/action/admin/indices/create/RemoteSplitIndexIT.java
@@ -0,0 +1,506 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.action.admin.indices.create;
+
+import org.apache.lucene.search.join.ScoreMode;
+import org.apache.lucene.util.Constants;
+import org.opensearch.Version;
+import org.opensearch.action.admin.cluster.state.ClusterStateRequest;
+import org.opensearch.action.admin.cluster.state.ClusterStateResponse;
+import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
+import org.opensearch.action.admin.indices.shrink.ResizeType;
+import org.opensearch.action.admin.indices.stats.CommonStats;
+import org.opensearch.action.admin.indices.stats.IndicesStatsResponse;
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.action.get.GetResponse;
+import org.opensearch.action.index.IndexRequest;
+import org.opensearch.action.index.IndexRequestBuilder;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.client.Client;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.metadata.MetadataCreateIndexService;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.routing.Murmur3HashFunction;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.cluster.routing.allocation.decider.EnableAllocationDecider;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.xcontent.MediaTypeRegistry;
+import org.opensearch.index.IndexModule;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.engine.SegmentsStats;
+import org.opensearch.index.query.TermsQueryBuilder;
+import org.opensearch.index.seqno.SeqNoStats;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
+import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
+import org.opensearch.test.VersionUtils;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.BiFunction;
+import java.util.stream.IntStream;
+
+import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_NUMBER_OF_REPLICAS;
+import static org.opensearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.opensearch.index.query.QueryBuilders.nestedQuery;
+import static org.opensearch.index.query.QueryBuilders.termQuery;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
+import static org.hamcrest.Matchers.equalTo;
+
+public class RemoteSplitIndexIT extends RemoteStoreBaseIntegTestCase {
+
+    @Override
+    protected boolean forbidPrivateIndexSettings() {
+        return false;
+    }
+
+    public Settings indexSettings() {
+        return Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(SETTING_NUMBER_OF_REPLICAS, 0)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .build();
+    }
+
+    public void testCreateSplitIndexToN() throws IOException {
+        int[][] possibleShardSplits = new int[][] { { 2, 4, 8 }, { 3, 6, 12 }, { 1, 2, 4 } };
+        int[] shardSplits = randomFrom(possibleShardSplits);
+        splitToN(shardSplits[0], shardSplits[1], shardSplits[2]);
+    }
+
+    public void testSplitFromOneToN() {
+
+        assumeFalse("https://github.com/elastic/elasticsearch/issues/34080", Constants.WINDOWS);
+
+        splitToN(1, 5, 10);
+        client().admin().indices().prepareDelete("*").get();
+        int randomSplit = randomIntBetween(2, 6);
+        splitToN(1, randomSplit, randomSplit * 2);
+    }
+
+    private void splitToN(int sourceShards, int firstSplitShards, int secondSplitShards) {
+
+        assertEquals(sourceShards, (sourceShards * firstSplitShards) / firstSplitShards);
+        assertEquals(firstSplitShards, (firstSplitShards * secondSplitShards) / secondSplitShards);
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        final boolean useRouting = randomBoolean();
+        final boolean useNested = randomBoolean();
+        final boolean useMixedRouting = useRouting ? randomBoolean() : false;
+        CreateIndexRequestBuilder createInitialIndex = prepareCreate("source");
+        Settings.Builder settings = Settings.builder().put(indexSettings()).put("number_of_shards", sourceShards);
+        final boolean useRoutingPartition;
+        if (randomBoolean()) {
+            // randomly set the value manually
+            int routingShards = secondSplitShards * randomIntBetween(1, 10);
+            settings.put("index.number_of_routing_shards", routingShards);
+            useRoutingPartition = false;
+        } else {
+            useRoutingPartition = randomBoolean();
+        }
+        if (useRouting && useMixedRouting == false && useRoutingPartition) {
+            int numRoutingShards = MetadataCreateIndexService.calculateNumRoutingShards(secondSplitShards, Version.CURRENT) - 1;
+            settings.put("index.routing_partition_size", randomIntBetween(1, numRoutingShards));
+            if (useNested) {
+                createInitialIndex.setMapping("_routing", "required=true", "nested1", "type=nested");
+            } else {
+                createInitialIndex.setMapping("_routing", "required=true");
+            }
+        } else if (useNested) {
+            createInitialIndex.setMapping("nested1", "type=nested");
+        }
+        logger.info("use routing {} use mixed routing {} use nested {}", useRouting, useMixedRouting, useNested);
+        createInitialIndex.setSettings(settings).get();
+
+        int numDocs = randomIntBetween(10, 50);
+        String[] routingValue = new String[numDocs];
+
+        BiFunction<String, Integer, IndexRequestBuilder> indexFunc = (index, id) -> {
+            try {
+                return client().prepareIndex(index)
+                    .setId(Integer.toString(id))
+                    .setSource(
+                        jsonBuilder().startObject()
+                            .field("foo", "bar")
+                            .field("i", id)
+                            .startArray("nested1")
+                            .startObject()
+                            .field("n_field1", "n_value1_1")
+                            .field("n_field2", "n_value2_1")
+                            .endObject()
+                            .startObject()
+                            .field("n_field1", "n_value1_2")
+                            .field("n_field2", "n_value2_2")
+                            .endObject()
+                            .endArray()
+                            .endObject()
+                    );
+            } catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        };
+        for (int i = 0; i < numDocs; i++) {
+            IndexRequestBuilder builder = indexFunc.apply("source", i);
+            if (useRouting) {
+                String routing = randomRealisticUnicodeOfCodepointLengthBetween(1, 10);
+                if (useMixedRouting && randomBoolean()) {
+                    routingValue[i] = null;
+                } else {
+                    routingValue[i] = routing;
+                }
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+
+        if (randomBoolean()) {
+            for (int i = 0; i < numDocs; i++) { // let's introduce some updates / deletes on the index
+                if (randomBoolean()) {
+                    IndexRequestBuilder builder = indexFunc.apply("source", i);
+                    if (useRouting) {
+                        builder.setRouting(routingValue[i]);
+                    }
+                    builder.get();
+                }
+            }
+        }
+
+        ensureYellow();
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+        Settings.Builder firstSplitSettingsBuilder = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", firstSplitShards)
+            .putNull("index.blocks.write");
+        if (sourceShards == 1 && useRoutingPartition == false && randomBoolean()) { // try to set it if we have a source index with 1 shard
+            firstSplitSettingsBuilder.put("index.number_of_routing_shards", secondSplitShards);
+        }
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "first_split")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(firstSplitSettingsBuilder.build())
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+
+        for (int i = 0; i < numDocs; i++) { // now update
+            IndexRequestBuilder builder = indexFunc.apply("first_split", i);
+            if (useRouting) {
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+        flushAndRefresh();
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        for (int i = 0; i < numDocs; i++) {
+            GetResponse getResponse = client().prepareGet("first_split", Integer.toString(i)).setRouting(routingValue[i]).get();
+            assertTrue(getResponse.isExists());
+        }
+
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("first_split")
+            .setSettings(Settings.builder().put("index.blocks.write", true))
+            .get();
+        ensureGreen();
+        // now split source into a new index
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("first_split", "second_split")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(
+                    Settings.builder()
+                        .put("index.number_of_replicas", 0)
+                        .put("index.number_of_shards", secondSplitShards)
+                        .putNull("index.blocks.write")
+                        .build()
+                )
+                .get()
+        );
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        // let it be allocated anywhere and bump replicas
+        client().admin()
+            .indices()
+            .prepareUpdateSettings("second_split")
+            .setSettings(Settings.builder().put("index.number_of_replicas", 0))
+            .get();
+        ensureGreen();
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+
+        for (int i = 0; i < numDocs; i++) { // now update
+            IndexRequestBuilder builder = indexFunc.apply("second_split", i);
+            if (useRouting) {
+                builder.setRouting(routingValue[i]);
+            }
+            builder.get();
+        }
+        flushAndRefresh();
+        for (int i = 0; i < numDocs; i++) {
+            GetResponse getResponse = client().prepareGet("second_split", Integer.toString(i)).setRouting(routingValue[i]).get();
+            assertTrue(getResponse.isExists());
+        }
+        assertHitCount(client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        assertHitCount(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+        if (useNested) {
+            assertNested("source", numDocs);
+            assertNested("first_split", numDocs);
+            assertNested("second_split", numDocs);
+        }
+        assertAllUniqueDocs(
+            client().prepareSearch("second_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+            numDocs
+        );
+        assertAllUniqueDocs(
+            client().prepareSearch("first_split").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+            numDocs
+        );
+        assertAllUniqueDocs(client().prepareSearch("source").setSize(100).setQuery(new TermsQueryBuilder("foo", "bar")).get(), numDocs);
+    }
+
+    public void assertNested(String index, int numDocs) {
+        // now, do a nested query
+        SearchResponse searchResponse = client().prepareSearch(index)
+            .setQuery(nestedQuery("nested1", termQuery("nested1.n_field1", "n_value1_1"), ScoreMode.Avg))
+            .get();
+        assertNoFailures(searchResponse);
+        assertThat(searchResponse.getHits().getTotalHits().value, equalTo((long) numDocs));
+    }
+
+    public void assertAllUniqueDocs(SearchResponse response, int numDocs) {
+        Set<String> ids = new HashSet<>();
+        for (int i = 0; i < response.getHits().getHits().length; i++) {
+            String id = response.getHits().getHits()[i].getId();
+            assertTrue("found ID " + id + " more than once", ids.add(id));
+        }
+        assertEquals(numDocs, ids.size());
+    }
+
+    public void testSplitIndexPrimaryTerm() throws Exception {
+        int numberOfTargetShards = randomIntBetween(2, 20);
+        int numberOfShards = randomValueOtherThanMany(n -> numberOfTargetShards % n != 0, () -> between(1, numberOfTargetShards - 1));
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        prepareCreate("source").setSettings(
+            Settings.builder()
+                .put(indexSettings())
+                .put("number_of_shards", numberOfShards)
+                .put("index.number_of_routing_shards", numberOfTargetShards)
+        ).get();
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to allocate many shards
+
+        // fail random primary shards to force primary terms to increase
+        final Index source = resolveIndex("source");
+        final int iterations = scaledRandomIntBetween(0, 16);
+        for (int i = 0; i < iterations; i++) {
+            final String node = randomSubsetOf(1, internalCluster().nodesInclude("source")).get(0);
+            final IndicesService indexServices = internalCluster().getInstance(IndicesService.class, node);
+            final IndexService indexShards = indexServices.indexServiceSafe(source);
+            for (final Integer shardId : indexShards.shardIds()) {
+                final IndexShard shard = indexShards.getShard(shardId);
+                if (shard.routingEntry().primary() && randomBoolean()) {
+                    disableAllocation("source");
+                    shard.failShard("test", new Exception("test"));
+                    // this can not succeed until the shard is failed and a replica is promoted
+                    int id = 0;
+                    while (true) {
+                        // find an ID that routes to the right shard, we will only index to the shard that saw a primary failure
+                        final String s = Integer.toString(id);
+                        final int hash = Math.floorMod(Murmur3HashFunction.hash(s), numberOfShards);
+                        if (hash == shardId) {
+                            final IndexRequest request = new IndexRequest("source").id(s)
+                                .source("{ \"f\": \"" + s + "\"}", MediaTypeRegistry.JSON);
+                            client().index(request).get();
+                            break;
+                        } else {
+                            id++;
+                        }
+                    }
+                    enableAllocation("source");
+                    ensureGreen();
+                }
+            }
+        }
+
+        final Settings.Builder prepareSplitSettings = Settings.builder().put("index.blocks.write", true);
+        client().admin().indices().prepareUpdateSettings("source").setSettings(prepareSplitSettings).get();
+        ensureYellow();
+
+        final IndexMetadata indexMetadata = indexMetadata(client(), "source");
+        final long beforeSplitPrimaryTerm = IntStream.range(0, numberOfShards).mapToLong(indexMetadata::primaryTerm).max().getAsLong();
+
+        // now split source into target
+        final Settings splitSettings = Settings.builder()
+            .put("index.number_of_replicas", 0)
+            .put("index.number_of_shards", numberOfTargetShards)
+            .putNull("index.blocks.write")
+            .build();
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareResizeIndex("source", "target")
+                .setResizeType(ResizeType.SPLIT)
+                .setSettings(splitSettings)
+                .get()
+        );
+
+        ensureGreen(TimeValue.timeValueSeconds(120)); // needs more than the default to relocate many shards
+
+        final IndexMetadata aftersplitIndexMetadata = indexMetadata(client(), "target");
+        for (int shardId = 0; shardId < numberOfTargetShards; shardId++) {
+            assertThat(aftersplitIndexMetadata.primaryTerm(shardId), equalTo(beforeSplitPrimaryTerm + 1));
+        }
+    }
+
+    private static IndexMetadata indexMetadata(final Client client, final String index) {
+        final ClusterStateResponse clusterStateResponse = client.admin().cluster().state(new ClusterStateRequest()).actionGet();
+        return clusterStateResponse.getState().metadata().index(index);
+    }
+
+    public void testCreateSplitIndex() throws Exception {
+        internalCluster().ensureAtLeastNumDataNodes(2);
+        Version version = VersionUtils.randomIndexCompatibleVersion(random());
+        prepareCreate("source").setSettings(
+            Settings.builder().put(indexSettings()).put("number_of_shards", 1).put("index.version.created", version)
+        ).get();
+        final int docs = randomIntBetween(0, 128);
+        for (int i = 0; i < docs; i++) {
+            client().prepareIndex("source").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+        }
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
+        // relocate all shards to one node such that we can merge it.
+        client().admin().indices().prepareUpdateSettings("source").setSettings(Settings.builder().put("index.blocks.write", true)).get();
+        ensureGreen();
+
+        final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
+
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"))
+            .get();
+        try {
+            assertAcked(
+                client().admin()
+                    .indices()
+                    .prepareResizeIndex("source", "target")
+                    .setResizeType(ResizeType.SPLIT)
+                    .setSettings(
+                        Settings.builder()
+                            .put("index.number_of_replicas", 0)
+                            .put("index.number_of_shards", 2)
+                            .putNull("index.blocks.write")
+                            .build()
+                    )
+                    .get()
+            );
+            ensureGreen();
+
+            final ClusterState state = client().admin().cluster().prepareState().get().getState();
+            DiscoveryNode mergeNode = state.nodes().get(state.getRoutingTable().index("target").shard(0).primaryShard().currentNodeId());
+            logger.info("split node {}", mergeNode);
+
+            final long maxSeqNo = Arrays.stream(sourceStats.getShards())
+                .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+                .map(ShardStats::getSeqNoStats)
+                .mapToLong(SeqNoStats::getMaxSeqNo)
+                .max()
+                .getAsLong();
+            final long maxUnsafeAutoIdTimestamp = Arrays.stream(sourceStats.getShards())
+                .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+                .map(ShardStats::getStats)
+                .map(CommonStats::getSegments)
+                .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
+                .max()
+                .getAsLong();
+
+            final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
+            for (final ShardStats shardStats : targetStats.getShards()) {
+                final SeqNoStats seqNoStats = shardStats.getSeqNoStats();
+                final ShardRouting shardRouting = shardStats.getShardRouting();
+                assertThat("failed on " + shardRouting, seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
+                assertThat("failed on " + shardRouting, seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+                assertThat(
+                    "failed on " + shardRouting,
+                    shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(),
+                    equalTo(maxUnsafeAutoIdTimestamp)
+                );
+            }
+
+            final int size = docs > 0 ? 2 * docs : 1;
+            assertHitCount(client().prepareSearch("target").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+
+            for (int i = docs; i < 2 * docs; i++) {
+                client().prepareIndex("target").setSource("{\"foo\" : \"bar\", \"i\" : " + i + "}", MediaTypeRegistry.JSON).get();
+            }
+            flushAndRefresh();
+            assertHitCount(
+                client().prepareSearch("target").setSize(2 * size).setQuery(new TermsQueryBuilder("foo", "bar")).get(),
+                2 * docs
+            );
+            assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
+            GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
+            assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+        } finally {
+            // clean up
+            client().admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setTransientSettings(
+                    Settings.builder().put(EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String) null)
+                )
+                .get();
+        }
+
+    }
+
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java b/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
index 59eef3c06844b..dfde1b958882c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/gateway/remote/RemoteClusterStateServiceIT.java
@@ -90,10 +90,10 @@ public void testFullClusterRestoreStaleDelete() throws Exception {
 
         assertEquals(10, repository.blobStore().blobContainer(baseMetadataPath.add("manifest")).listBlobsByPrefix("manifest").size());
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             cluster().getClusterName(),
             getClusterState().metadata().clusterUUID()
-        ).getIndices();
+        ).getMetadata().getIndices();
         assertEquals(0, indexMetadataMap.values().stream().findFirst().get().getNumberOfReplicas());
         assertEquals(shardCount, indexMetadataMap.values().stream().findFirst().get().getNumberOfShards());
     }
@@ -114,6 +114,31 @@ public void testRemoteStateStats() {
             .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
             .get();
 
+        // assert cluster state stats
+        assertClusterManagerClusterStateStats(nodesStatsResponse);
+
+        NodesStatsResponse nodesStatsResponseDataNode = client().admin()
+            .cluster()
+            .prepareNodesStats(dataNode)
+            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+            .get();
+        // assert cluster state stats for data node
+        DiscoveryStats dataNodeDiscoveryStats = nodesStatsResponseDataNode.getNodes().get(0).getDiscoveryStats();
+        assertNotNull(dataNodeDiscoveryStats.getClusterStateStats());
+        assertEquals(0, dataNodeDiscoveryStats.getClusterStateStats().getUpdateSuccess());
+
+        // call nodes/stats with nodeId filter
+        NodesStatsResponse nodesStatsNodeIdFilterResponse = client().admin()
+            .cluster()
+            .prepareNodesStats(dataNode)
+            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+            .setNodesIds(clusterManagerNode)
+            .get();
+
+        assertClusterManagerClusterStateStats(nodesStatsNodeIdFilterResponse);
+    }
+
+    private void assertClusterManagerClusterStateStats(NodesStatsResponse nodesStatsResponse) {
         // assert cluster state stats
         DiscoveryStats discoveryStats = nodesStatsResponse.getNodes().get(0).getDiscoveryStats();
 
@@ -125,16 +150,43 @@ public void testRemoteStateStats() {
         assertTrue(discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getSuccessCount() > 1);
         assertEquals(0, discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getFailedCount());
         assertTrue(discoveryStats.getClusterStateStats().getPersistenceStats().get(0).getTotalTimeInMillis() > 0);
+    }
 
-        NodesStatsResponse nodesStatsResponseDataNode = client().admin()
-            .cluster()
-            .prepareNodesStats(dataNode)
-            .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
-            .get();
-        // assert cluster state stats for data node
-        DiscoveryStats dataNodeDiscoveryStats = nodesStatsResponseDataNode.getNodes().get(0).getDiscoveryStats();
-        assertNotNull(dataNodeDiscoveryStats.getClusterStateStats());
-        assertEquals(0, dataNodeDiscoveryStats.getClusterStateStats().getUpdateSuccess());
+    public void testRemoteStateStatsFromAllNodes() {
+        int shardCount = randomIntBetween(1, 5);
+        int replicaCount = 1;
+        int dataNodeCount = shardCount * (replicaCount + 1);
+        int clusterManagerNodeCount = 3;
+        prepareCluster(clusterManagerNodeCount, dataNodeCount, INDEX_NAME, replicaCount, shardCount);
+        String[] allNodes = internalCluster().getNodeNames();
+        // call _nodes/stats/discovery from all the nodes
+        for (String node : allNodes) {
+            NodesStatsResponse nodesStatsResponse = client().admin()
+                .cluster()
+                .prepareNodesStats(node)
+                .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+                .get();
+            validateNodesStatsResponse(nodesStatsResponse);
+        }
+
+        // call _nodes/stats/discovery from all the nodes with random nodeId filter
+        for (String node : allNodes) {
+            NodesStatsResponse nodesStatsResponse = client().admin()
+                .cluster()
+                .prepareNodesStats(node)
+                .addMetric(NodesStatsRequest.Metric.DISCOVERY.metricName())
+                .setNodesIds(allNodes[randomIntBetween(0, allNodes.length - 1)])
+                .get();
+            validateNodesStatsResponse(nodesStatsResponse);
+        }
+    }
+
+    private void validateNodesStatsResponse(NodesStatsResponse nodesStatsResponse) {
+        // _nodes/stats/discovery must never fail due to any exception
+        assertFalse(nodesStatsResponse.toString().contains("exception"));
+        assertNotNull(nodesStatsResponse.getNodes());
+        assertNotNull(nodesStatsResponse.getNodes().get(0));
+        assertNotNull(nodesStatsResponse.getNodes().get(0).getDiscoveryStats());
     }
 
     private void setReplicaCount(int replicaCount) {
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
index a1815d9be2daf..51dba07a8f9f8 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java
@@ -539,7 +539,7 @@ public void testCanCache() throws Exception {
         assertCacheState(client, "index", 0, 4);
     }
 
-    public void testCacheWithFilteredAlias() {
+    public void testCacheWithFilteredAlias() throws InterruptedException {
         Client client = client();
         Settings settings = Settings.builder()
             .put(IndicesRequestCache.INDEX_CACHE_REQUEST_ENABLED_SETTING.getKey(), true)
@@ -562,6 +562,8 @@ public void testCacheWithFilteredAlias() {
         OpenSearchAssertions.assertAllSuccessful(forceMergeResponse);
         refresh();
 
+        indexRandomForConcurrentSearch("index");
+
         assertCacheState(client, "index", 0, 0);
 
         SearchResponse r1 = client.prepareSearch("index")
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
index 186a5ce39f131..a82fd8d845709 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
@@ -19,7 +19,6 @@
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REPLICATION_TYPE;
-import static org.opensearch.indices.IndicesService.CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_SETTING_REPLICATION_TYPE;
 
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
@@ -124,30 +123,4 @@ public void testIndexReplicationSettingOverridesDocRepClusterSetting() throws Ex
         assertEquals(indicesService.indexService(anotherIndex).getIndexSettings().isSegRepEnabled(), false);
     }
 
-    public void testIndexReplicationTypeWhenRestrictSettingTrue() {
-        testRestrictIndexReplicationTypeSetting(true, randomFrom(ReplicationType.values()));
-    }
-
-    public void testIndexReplicationTypeWhenRestrictSettingFalse() {
-        testRestrictIndexReplicationTypeSetting(false, randomFrom(ReplicationType.values()));
-    }
-
-    private void testRestrictIndexReplicationTypeSetting(boolean setRestrict, ReplicationType replicationType) {
-        String expectedExceptionMsg =
-            "Validation Failed: 1: index setting [index.replication.type] is not allowed to be set as [cluster.restrict.index.replication_type=true];";
-        String clusterManagerName = internalCluster().startNode(
-            Settings.builder().put(CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING.getKey(), setRestrict).build()
-        );
-        internalCluster().startDataOnlyNodes(1);
-
-        // Test create index fails
-        Settings indexSettings = Settings.builder().put(indexSettings()).put(SETTING_REPLICATION_TYPE, replicationType).build();
-        if (setRestrict) {
-            IllegalArgumentException exception = expectThrows(IllegalArgumentException.class, () -> createIndex(INDEX_NAME, indexSettings));
-            assertEquals(expectedExceptionMsg, exception.getMessage());
-        } else {
-            createIndex(INDEX_NAME, indexSettings);
-        }
-    }
-
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
index f48df082a25dc..9c93a8f85db8e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
@@ -22,6 +22,7 @@
 import org.apache.lucene.index.StandardDirectoryReader;
 import org.apache.lucene.tests.util.TestUtil;
 import org.apache.lucene.util.BytesRef;
+import org.opensearch.action.admin.cluster.stats.ClusterStatsResponse;
 import org.opensearch.action.admin.indices.alias.Alias;
 import org.opensearch.action.admin.indices.flush.FlushRequest;
 import org.opensearch.action.admin.indices.stats.IndicesStatsRequest;
@@ -62,6 +63,7 @@
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexModule;
+import org.opensearch.index.ReplicationStats;
 import org.opensearch.index.SegmentReplicationPerGroupStats;
 import org.opensearch.index.SegmentReplicationPressureService;
 import org.opensearch.index.SegmentReplicationShardStats;
@@ -94,6 +96,7 @@
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
 import static java.util.Arrays.asList;
@@ -1063,9 +1066,14 @@ public void testScrollCreatedOnReplica() throws Exception {
 
         client(replica).prepareClearScroll().addScrollId(searchResponse.getScrollId()).get();
 
-        currentFiles = List.of(replicaShard.store().directory().listAll());
-        assertFalse("Files should be cleaned up post scroll clear request", currentFiles.containsAll(snapshottedSegments));
+        assertBusy(
+            () -> assertFalse(
+                "Files should be cleaned up post scroll clear request",
+                List.of(replicaShard.store().directory().listAll()).containsAll(snapshottedSegments)
+            )
+        );
         assertEquals(100, scrollHits);
+
     }
 
     /**
@@ -1324,9 +1332,12 @@ public void testPitCreatedOnReplica() throws Exception {
         // delete the PIT
         DeletePitRequest deletePITRequest = new DeletePitRequest(pitResponse.getId());
         client().execute(DeletePitAction.INSTANCE, deletePITRequest).actionGet();
-
-        currentFiles = List.of(replicaShard.store().directory().listAll());
-        assertFalse("Files should be cleaned up", currentFiles.containsAll(snapshottedSegments));
+        assertBusy(
+            () -> assertFalse(
+                "Files should be cleaned up",
+                List.of(replicaShard.store().directory().listAll()).containsAll(snapshottedSegments)
+            )
+        );
     }
 
     /**
@@ -1776,4 +1787,58 @@ public void testRealtimeTermVectorRequestsUnSuccessful() throws IOException {
         assertThat(response.getIndex(), equalTo(INDEX_NAME));
 
     }
+
+    public void testReplicaAlreadyAtCheckpoint() throws Exception {
+        final List<String> nodes = new ArrayList<>();
+        final String primaryNode = internalCluster().startDataOnlyNode();
+        nodes.add(primaryNode);
+        final Settings settings = Settings.builder().put(indexSettings()).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0).build();
+        createIndex(INDEX_NAME, settings);
+        ensureGreen(INDEX_NAME);
+        // start a replica node, initially will be empty with no shard assignment.
+        final String replicaNode = internalCluster().startDataOnlyNode();
+        nodes.add(replicaNode);
+        final String replicaNode2 = internalCluster().startDataOnlyNode();
+        assertAcked(
+            client().admin()
+                .indices()
+                .prepareUpdateSettings(INDEX_NAME)
+                .setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 2))
+        );
+        ensureGreen(INDEX_NAME);
+
+        // index a doc.
+        client().prepareIndex(INDEX_NAME).setId("1").setSource("foo", randomInt()).get();
+        refresh(INDEX_NAME);
+
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNode));
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        IndexShard replica_1 = getIndexShard(replicaNode, INDEX_NAME);
+        IndexShard replica_2 = getIndexShard(replicaNode2, INDEX_NAME);
+        // wait until a replica is promoted & finishes engine flip, we don't care which one
+        AtomicReference<IndexShard> primary = new AtomicReference<>();
+        assertBusy(() -> {
+            assertTrue("replica should be promoted as a primary", replica_1.routingEntry().primary() || replica_2.routingEntry().primary());
+            primary.set(replica_1.routingEntry().primary() ? replica_1 : replica_2);
+        });
+
+        FlushRequest request = new FlushRequest(INDEX_NAME);
+        request.force(true);
+        primary.get().flush(request);
+
+        assertBusy(() -> {
+            assertEquals(
+                replica_1.getLatestReplicationCheckpoint().getSegmentInfosVersion(),
+                replica_2.getLatestReplicationCheckpoint().getSegmentInfosVersion()
+            );
+        });
+
+        assertBusy(() -> {
+            ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
+            ReplicationStats replicationStats = clusterStatsResponse.getIndicesStats().getSegments().getReplicationStats();
+            assertEquals(0L, replicationStats.maxBytesBehind);
+            assertEquals(0L, replicationStats.maxReplicationLag);
+            assertEquals(0L, replicationStats.totalBytesBehind);
+        });
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
index 9e0b2a66467de..21ce4be9981fb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteRestoreSnapshotIT.java
@@ -330,6 +330,8 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         assertEquals(restoreSnapshotResponse1.status(), RestStatus.ACCEPTED);
         assertEquals(restoreSnapshotResponse2.status(), RestStatus.ACCEPTED);
         ensureGreen(indexName1, restoredIndexName2);
+
+        assertRemoteSegmentsAndTranslogUploaded(restoredIndexName2);
         assertDocsPresentInIndex(client, indexName1, numDocsInIndex1);
         assertDocsPresentInIndex(client, restoredIndexName2, numDocsInIndex2);
         // indexing some new docs and validating
@@ -355,6 +357,29 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         assertDocsPresentInIndex(client, indexName1, numDocsInIndex1 + 4);
     }
 
+    void assertRemoteSegmentsAndTranslogUploaded(String idx) throws IOException {
+        String indexUUID = client().admin().indices().prepareGetSettings(idx).get().getSetting(idx, IndexMetadata.SETTING_INDEX_UUID);
+
+        Path remoteTranslogMetadataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/metadata");
+        Path remoteTranslogDataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/data");
+        Path segmentMetadataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/segments/metadata");
+        Path segmentDataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/segments/data");
+
+        try (
+            Stream<Path> translogMetadata = Files.list(remoteTranslogMetadataPath);
+            Stream<Path> translogData = Files.list(remoteTranslogDataPath);
+            Stream<Path> segmentMetadata = Files.list(segmentMetadataPath);
+            Stream<Path> segmentData = Files.list(segmentDataPath);
+
+        ) {
+            assertTrue(translogData.count() > 0);
+            assertTrue(translogMetadata.count() > 0);
+            assertTrue(segmentMetadata.count() > 0);
+            assertTrue(segmentData.count() > 0);
+        }
+
+    }
+
     public void testRemoteRestoreIndexRestoredFromSnapshot() throws IOException, ExecutionException, InterruptedException {
         internalCluster().startClusterManagerOnlyNode();
         internalCluster().startDataOnlyNodes(2);
@@ -395,23 +420,7 @@ public void testRemoteRestoreIndexRestoredFromSnapshot() throws IOException, Exe
         ensureGreen(indexName1);
         assertDocsPresentInIndex(client(), indexName1, numDocsInIndex1);
 
-        // Make sure remote translog is empty
-        String indexUUID = client().admin()
-            .indices()
-            .prepareGetSettings(indexName1)
-            .get()
-            .getSetting(indexName1, IndexMetadata.SETTING_INDEX_UUID);
-
-        Path remoteTranslogMetadataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/metadata");
-        Path remoteTranslogDataPath = Path.of(String.valueOf(remoteRepoPath), indexUUID, "/0/translog/data");
-
-        try (
-            Stream<Path> translogMetadata = Files.list(remoteTranslogMetadataPath);
-            Stream<Path> translogData = Files.list(remoteTranslogDataPath)
-        ) {
-            assertTrue(translogData.count() > 0);
-            assertTrue(translogMetadata.count() > 0);
-        }
+        assertRemoteSegmentsAndTranslogUploaded(indexName1);
 
         // Clear the local data before stopping the node. This will make sure that remote translog is empty.
         IndexShard indexShard = getIndexShard(primaryNodeName(indexName1), indexName1);
@@ -580,4 +589,71 @@ public void testRestoreShallowSnapshotRepository() throws ExecutionException, In
         assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
     }
 
+    public void testRestoreShallowSnapshotIndexAfterSnapshot() throws ExecutionException, InterruptedException {
+        String indexName1 = "testindex1";
+        String snapshotRepoName = "test-restore-snapshot-repo";
+        String remoteStoreRepoNameUpdated = "test-rs-repo-updated" + TEST_REMOTE_STORE_REPO_SUFFIX;
+        String snapshotName1 = "test-restore-snapshot1";
+        Path absolutePath1 = randomRepoPath().toAbsolutePath();
+        Path absolutePath2 = randomRepoPath().toAbsolutePath();
+        String[] pathTokens = absolutePath1.toString().split("/");
+        String basePath = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location = PathUtils.get(String.join("/", pathTokens));
+        pathTokens = absolutePath2.toString().split("/");
+        String basePath2 = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location2 = PathUtils.get(String.join("/", pathTokens));
+        logger.info("Path 1 [{}]", absolutePath1);
+        logger.info("Path 2 [{}]", absolutePath2);
+        String restoredIndexName1 = indexName1 + "-restored";
+
+        createRepository(snapshotRepoName, "fs", getRepositorySettings(location, basePath, true));
+
+        Client client = client();
+        Settings indexSettings = Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+            .build();
+        createIndex(indexName1, indexSettings);
+
+        int numDocsInIndex1 = randomIntBetween(2, 5);
+        indexDocuments(client, indexName1, numDocsInIndex1);
+
+        ensureGreen(indexName1);
+
+        logger.info("--> snapshot");
+        SnapshotInfo snapshotInfo1 = createSnapshot(snapshotRepoName, snapshotName1, new ArrayList<>(List.of(indexName1)));
+        assertThat(snapshotInfo1.successfulShards(), greaterThan(0));
+        assertThat(snapshotInfo1.successfulShards(), equalTo(snapshotInfo1.totalShards()));
+        assertThat(snapshotInfo1.state(), equalTo(SnapshotState.SUCCESS));
+
+        int extraNumDocsInIndex1 = randomIntBetween(20, 50);
+        indexDocuments(client, indexName1, extraNumDocsInIndex1);
+        refresh(indexName1);
+
+        client().admin().indices().close(Requests.closeIndexRequest(indexName1)).get();
+        createRepository(remoteStoreRepoNameUpdated, "fs", remoteRepoPath);
+        RestoreSnapshotResponse restoreSnapshotResponse2 = client.admin()
+            .cluster()
+            .prepareRestoreSnapshot(snapshotRepoName, snapshotName1)
+            .setWaitForCompletion(true)
+            .setIndices(indexName1)
+            .setRenamePattern(indexName1)
+            .setRenameReplacement(restoredIndexName1)
+            .setSourceRemoteStoreRepository(remoteStoreRepoNameUpdated)
+            .get();
+
+        assertTrue(restoreSnapshotResponse2.getRestoreInfo().failedShards() == 0);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1);
+
+        // indexing some new docs and validating
+        indexDocuments(client, restoredIndexName1, numDocsInIndex1, numDocsInIndex1 + 2);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
+    }
+
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
index bccca283ba772..8b4981a15433a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
@@ -56,7 +56,7 @@ public class RemoteStoreBaseIntegTestCase extends OpenSearchIntegTestCase {
     protected static final String REPOSITORY_NAME = "test-remote-store-repo";
     protected static final String REPOSITORY_2_NAME = "test-remote-store-repo-2";
     protected static final int SHARD_COUNT = 1;
-    protected static final int REPLICA_COUNT = 1;
+    protected static int REPLICA_COUNT = 1;
     protected static final String TOTAL_OPERATIONS = "total-operations";
     protected static final String REFRESHED_OR_FLUSHED_OPERATIONS = "refreshed-or-flushed-operations";
     protected static final String MAX_SEQ_NO_TOTAL = "max-seq-no-total";
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
index e9afd6d36bb87..c61e2ec6e4f6c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreClusterStateRestoreIT.java
@@ -30,6 +30,7 @@
 import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.ExecutionException;
@@ -85,6 +86,7 @@ public void testFullClusterRestore() throws Exception {
         // Step - 1 index some data to generate files in remote directory
         Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
         // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
         resetCluster(dataNodeCount, clusterManagerNodeCount);
@@ -92,9 +94,17 @@ public void testFullClusterRestore() throws Exception {
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 3 Trigger full cluster restore and validate
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
         validateMetadata(List.of(INDEX_NAME));
         verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, true);
+
     }
 
     /**
@@ -121,6 +131,7 @@ public void testFullClusterRestoreDoesntFailWithConflictingLocalState() throws E
         // index some data to generate files in remote directory
         Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
         // stop all nodes
         internalCluster().stopAllNodes();
@@ -156,6 +167,14 @@ public Settings onNodeStopped(String nodeName) {
         newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, ClusterState.UNKNOWN_UUID) : "cluster restart not successful. cluster uuid is still unknown";
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
+
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
         validateMetadata(List.of(INDEX_NAME));
 
         // start data nodes to trigger index data recovery
@@ -180,6 +199,7 @@ public void testFullClusterRestoreMultipleIndices() throws Exception {
         updateIndexBlock(true, secondIndexName);
 
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
         // Step - 2 Replace all nodes in the cluster with new nodes. This ensures new cluster state doesn't have previous index metadata
         resetCluster(dataNodeCount, clusterManagerNodeCount);
@@ -187,7 +207,14 @@ public void testFullClusterRestoreMultipleIndices() throws Exception {
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 3 Trigger full cluster restore
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
         validateMetadata(List.of(INDEX_NAME, secondIndexName));
         verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, false);
         verifyRedIndicesAndTriggerRestore(indexStats2, secondIndexName, false);
@@ -239,6 +266,7 @@ public void testRemoteStateFullRestart() throws Exception {
 
         Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, clusterManagerNodeCount);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
         // Delete index metadata file in remote
         try {
             Files.move(
@@ -257,6 +285,14 @@ public void testRemoteStateFullRestart() throws Exception {
         ensureGreen(INDEX_NAME);
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert Objects.equals(newClusterUUID, prevClusterUUID) : "Full restart not successful. cluster uuid has changed";
+
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
         validateCurrentMetadata();
         verifyRedIndicesAndTriggerRestore(indexStats, INDEX_NAME, true);
     }
@@ -309,6 +345,7 @@ public void testFullClusterRestoreGlobalMetadata() throws Exception {
         // Step - 1 index some data to generate files in remote directory
         Map<String, Long> indexStats = initialTestSetup(shardCount, replicaCount, dataNodeCount, 1);
         String prevClusterUUID = clusterService().state().metadata().clusterUUID();
+        long prevClusterStateVersion = clusterService().state().version();
 
         // Create global metadata - register a custom repo
         Path repoPath = registerCustomRepository();
@@ -328,8 +365,16 @@ public void testFullClusterRestoreGlobalMetadata() throws Exception {
         String newClusterUUID = clusterService().state().metadata().clusterUUID();
         assert !Objects.equals(newClusterUUID, prevClusterUUID) : "cluster restart not successful. cluster uuid is same";
 
-        // Step - 3 Trigger full cluster restore and validate
-        // validateCurrentMetadata();
+        // Step - 3 validate cluster state restored
+        long newClusterStateVersion = clusterService().state().version();
+        assert prevClusterStateVersion < newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is greater than current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
+
+        validateCurrentMetadata();
         assertEquals(Integer.valueOf(34), SETTING_CLUSTER_MAX_SHARDS_PER_NODE.get(clusterService().state().metadata().settings()));
         assertEquals(true, SETTING_READ_ONLY_SETTING.get(clusterService().state().metadata().settings()));
         assertTrue(clusterService().state().blocks().hasGlobalBlock(CLUSTER_READ_ONLY_BLOCK));
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java b/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
index 5207dab83f1d9..aa1fe695ecc12 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/SearchWeightedRoutingIT.java
@@ -501,8 +501,9 @@ public void testShardRoutingWithNetworkDisruption_FailOpenEnabled() throws Excep
 
         logger.info("--> creating network partition disruption");
         final String clusterManagerNode1 = internalCluster().getClusterManagerName();
-        Set<String> nodesInOneSide = Stream.of(clusterManagerNode1, nodeMap.get("b").get(0)).collect(Collectors.toCollection(HashSet::new));
-        Set<String> nodesInOtherSide = Stream.of(nodeMap.get("a").get(0)).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOneSide = Stream.of(nodeMap.get("a").get(0)).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOtherSide = Stream.of(clusterManagerNode1, nodeMap.get("b").get(0), nodeMap.get("c").get(0))
+            .collect(Collectors.toCollection(HashSet::new));
 
         NetworkDisruption networkDisruption = new NetworkDisruption(
             new NetworkDisruption.TwoPartitions(nodesInOneSide, nodesInOtherSide),
@@ -870,8 +871,7 @@ private void assertSearchInAZ(String az) {
             SearchStats.Stats searchStats = stat.getIndices().getSearch().getTotal();
             if (stat.getNode().isDataNode()) {
                 if (stat.getNode().getId().equals(dataNodeId)) {
-                    Assert.assertTrue(searchStats.getFetchCount() > 0L);
-                    Assert.assertTrue(searchStats.getQueryCount() > 0L);
+                    Assert.assertTrue(searchStats.getFetchCount() > 0L || searchStats.getQueryCount() > 0L);
                 }
             }
         }
@@ -945,7 +945,6 @@ public void testSearchAggregationWithNetworkDisruption_FailOpenEnabled() throws
         }
 
         logger.info("--> network disruption is stopped");
-        networkDisruption.stopDisrupting();
 
         for (int i = 0; i < 50; i++) {
             try {
@@ -962,6 +961,8 @@ public void testSearchAggregationWithNetworkDisruption_FailOpenEnabled() throws
                 fail("search should not fail");
             }
         }
+        networkDisruption.stopDisrupting();
+
         assertSearchInAZ("b");
         assertSearchInAZ("c");
         assertNoSearchInAZ("a");
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
index 865dd670fbf68..1d5f7f93e7410 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/DiversifiedSamplerIT.java
@@ -33,9 +33,9 @@
 
 import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 
-import org.opensearch.action.admin.indices.refresh.RefreshRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
+import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.TermQueryBuilder;
@@ -132,13 +132,14 @@ public void setupSuiteScopeCluster() throws Exception {
             client().prepareIndex("test")
                 .setId("" + i)
                 .setSource("author", parts[5], "name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
             client().prepareIndex("idx_unmapped_author")
                 .setId("" + i)
                 .setSource("name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
         }
-        client().admin().indices().refresh(new RefreshRequest("test")).get();
     }
 
     public void testIssue10719() throws Exception {
@@ -221,10 +222,6 @@ public void testNestedDiversity() throws Exception {
     }
 
     public void testNestedSamples() throws Exception {
-        assumeFalse(
-            "Concurrent search case muted pending fix: https://github.com/opensearch-project/OpenSearch/issues/10046",
-            internalCluster().clusterService().getClusterSettings().get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING)
-        );
         // Test samples nested under samples
         int MAX_DOCS_PER_AUTHOR = 1;
         int MAX_DOCS_PER_GENRE = 2;
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
index 7033c42c5d661..c7b03d21cb6bb 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/aggregations/bucket/SamplerIT.java
@@ -34,9 +34,9 @@
 
 import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 
-import org.opensearch.action.admin.indices.refresh.RefreshRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.search.SearchType;
+import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.TermQueryBuilder;
@@ -132,13 +132,14 @@ public void setupSuiteScopeCluster() throws Exception {
             client().prepareIndex("test")
                 .setId("" + i)
                 .setSource("author", parts[5], "name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
             client().prepareIndex("idx_unmapped_author")
                 .setId("" + i)
                 .setSource("name", parts[2], "genre", parts[8], "price", Float.parseFloat(parts[3]))
+                .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
                 .get();
         }
-        client().admin().indices().refresh(new RefreshRequest("test")).get();
     }
 
     public void testIssue10719() throws Exception {
@@ -195,6 +196,23 @@ public void testSimpleSampler() throws Exception {
         assertThat(maxBooksPerAuthor, equalTo(3L));
     }
 
+    public void testSimpleSamplerShardSize() throws Exception {
+        final int SHARD_SIZE = randomIntBetween(1, 3);
+        SamplerAggregationBuilder sampleAgg = sampler("sample").shardSize(SHARD_SIZE);
+        sampleAgg.subAggregation(terms("authors").field("author"));
+        SearchResponse response = client().prepareSearch("test")
+            .setSearchType(SearchType.QUERY_THEN_FETCH)
+            .setQuery(new TermQueryBuilder("genre", "fantasy"))
+            .setFrom(0)
+            .setSize(60)
+            .addAggregation(sampleAgg)
+            .get();
+        assertSearchResponse(response);
+        Sampler sample = response.getAggregations().get("sample");
+        Terms authors = sample.getAggregations().get("authors");
+        assertEquals(SHARD_SIZE * NUM_SHARDS, sample.getDocCount());
+    }
+
     public void testUnmappedChildAggNoDiversity() throws Exception {
         SamplerAggregationBuilder sampleAgg = sampler("sample").shardSize(100);
         sampleAgg.subAggregation(terms("authors").field("author"));
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
index 42d91ac945662..f7bc5eb75ad0f 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/fetch/subphase/highlight/HighlighterSearchIT.java
@@ -155,7 +155,7 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(InternalSettingsPlugin.class, MockKeywordPlugin.class, MockAnalysisPlugin.class);
     }
 
-    public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOException {
+    public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("properties")
@@ -177,6 +177,7 @@ public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOExceptio
             .setSource(jsonBuilder().startObject().array("tags", "foo baz", "foo baz", "foo baz", "foo bar").field("sort", 2).endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         for (BoundaryScannerType scanner : BoundaryScannerType.values()) {
             SearchResponse search = client().prepareSearch()
@@ -190,12 +191,13 @@ public void testHighlightingWithKeywordIgnoreBoundaryScanner() throws IOExceptio
         }
     }
 
-    public void testHighlightingWithStoredKeyword() throws IOException {
+    public void testHighlightingWithStoredKeyword() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("properties").startObject("text").field("type", "keyword").field("store", true).endObject().endObject();
         mappings.endObject();
         assertAcked(prepareCreate("test").setMapping(mappings));
+        indexRandomForConcurrentSearch("test");
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("text", "foo").endObject()).get();
         refresh();
         SearchResponse search = client().prepareSearch()
@@ -205,7 +207,7 @@ public void testHighlightingWithStoredKeyword() throws IOException {
         assertHighlight(search, 0, "text", 0, equalTo("<em>foo</em>"));
     }
 
-    public void testHighlightingWithWildcardName() throws IOException {
+    public void testHighlightingWithWildcardName() throws IOException, InterruptedException {
         // test the kibana case with * as fieldname that will try highlight all fields including meta fields
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
@@ -221,6 +223,7 @@ public void testHighlightingWithWildcardName() throws IOException {
         assertAcked(prepareCreate("test").setMapping(mappings));
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("text", "text").endObject()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             SearchResponse search = client().prepareSearch()
                 .setQuery(constantScoreQuery(matchQuery("text", "text")))
@@ -230,7 +233,7 @@ public void testHighlightingWithWildcardName() throws IOException {
         }
     }
 
-    public void testFieldAlias() throws IOException {
+    public void testFieldAlias() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("text")
@@ -248,7 +251,7 @@ public void testFieldAlias() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("text", "foo").get();
         refresh();
-
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             HighlightBuilder builder = new HighlightBuilder().field(new Field("alias").highlighterType(type))
                 .requireFieldMatch(randomBoolean());
@@ -257,7 +260,7 @@ public void testFieldAlias() throws IOException {
         }
     }
 
-    public void testFieldAliasWithSourceLookup() throws IOException {
+    public void testFieldAliasWithSourceLookup() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("text")
@@ -276,7 +279,7 @@ public void testFieldAliasWithSourceLookup() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("text", "foo bar").get();
         refresh();
-
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             HighlightBuilder builder = new HighlightBuilder().field(new Field("alias").highlighterType(type))
                 .requireFieldMatch(randomBoolean());
@@ -285,7 +288,7 @@ public void testFieldAliasWithSourceLookup() throws IOException {
         }
     }
 
-    public void testFieldAliasWithWildcardField() throws IOException {
+    public void testFieldAliasWithWildcardField() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder().startObject()
             .startObject("properties")
             .startObject("keyword")
@@ -301,13 +304,14 @@ public void testFieldAliasWithWildcardField() throws IOException {
 
         client().prepareIndex("test").setId("1").setSource("keyword", "foo").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         HighlightBuilder builder = new HighlightBuilder().field(new Field("al*")).requireFieldMatch(false);
         SearchResponse search = client().prepareSearch().setQuery(matchQuery("alias", "foo")).highlighter(builder).get();
         assertHighlight(search, 0, "alias", 0, equalTo("<em>foo</em>"));
     }
 
-    public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOException {
+    public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOException, InterruptedException {
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
         mappings.startObject("_source")
@@ -334,6 +338,7 @@ public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOExc
             .setSource(jsonBuilder().startObject().field("unstored_text", "text").field("text", "text").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         for (String type : ALL_TYPES) {
             SearchResponse search = client().prepareSearch()
                 .setQuery(constantScoreQuery(matchQuery("text", "text")))
@@ -350,7 +355,7 @@ public void testHighlightingWhenFieldsAreNotStoredThereIsNoSource() throws IOExc
     }
 
     // see #3486
-    public void testHighTermFrequencyDoc() throws IOException {
+    public void testHighTermFrequencyDoc() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping("name", "type=text,term_vector=with_positions_offsets,store=" + randomBoolean()));
         StringBuilder builder = new StringBuilder();
         for (int i = 0; i < 6000; i++) {
@@ -358,6 +363,7 @@ public void testHighTermFrequencyDoc() throws IOException {
         }
         client().prepareIndex("test").setId("1").setSource("name", builder.toString()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setQuery(constantScoreQuery(matchQuery("name", "abc")))
             .highlighter(new HighlightBuilder().field("name"))
@@ -385,6 +391,7 @@ public void testEnsureNoNegativeOffsets() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setQuery(matchQuery("long_term", "thisisaverylongwordandmakessurethisfails foo highlighed"))
             .highlighter(new HighlightBuilder().field("long_term", 18, 1).highlighterType("fvh"))
@@ -671,7 +678,7 @@ public void testHighlightIssue1994() throws Exception {
         assertHighlight(search, 0, "titleTV", 1, 2, equalTo("<em>highlight</em> other text"));
     }
 
-    public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() {
+    public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
@@ -684,6 +691,7 @@ public void testGlobalHighlightingSettingsOverriddenAtFieldLevel() {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1 and field2 produces different tags");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -734,6 +742,7 @@ public void testHighlightingOnWildcardFields() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field*");
         SearchSourceBuilder source = searchSource()
@@ -783,6 +792,7 @@ public void testForceSourceWithSourceDisabled() throws Exception {
             .setSource("field1", "The quick brown fox jumps over the lazy dog", "field2", "second field content")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // works using stored field
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -823,6 +833,7 @@ public void testPlainHighlighter() throws Exception {
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -1025,6 +1036,7 @@ public void testFVHManyMatches() throws Exception {
         String value = new String(new char[1024 * 256 / pattern.length()]).replace("\0", pattern);
         client().prepareIndex("test").setSource("field1", value).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1 with default phrase limit");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "t"))
@@ -1116,6 +1128,7 @@ private void checkMatchedFieldsCase(boolean requireFieldMatch) throws Exception
         );
         index("test", "type1", "3", "foo", "weird", "bar", "result");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         Field fooField = new Field("foo").numOfFragments(1)
             .order("score")
@@ -1408,6 +1421,7 @@ public void testMultiMapperVectorWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1453,6 +1467,7 @@ public void testMultiMapperVectorFromSource() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1498,6 +1513,7 @@ public void testMultiMapperNoVectorWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1542,6 +1558,7 @@ public void testMultiMapperNoVectorFromSource() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse search = client().prepareSearch()
@@ -1571,6 +1588,7 @@ public void testFastVectorHighlighterShouldFailIfNoTermVectors() throws Exceptio
                 .setSource("title", "This is a test for the enabling fast vector highlighter");
         }
         indexRandom(true, indexRequestBuilders);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch()
             .setQuery(matchPhraseQuery("title", "this is a test"))
@@ -1608,6 +1626,7 @@ public void testDisableFastVectorHighlighter() throws Exception {
                 .setSource("title", "This is a test for the workaround for the fast vector highlighting SOLR-3724");
         }
         indexRandom(true, indexRequestBuilders);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse search = client().prepareSearch()
             .setQuery(matchPhraseQuery("title", "test for the workaround"))
@@ -1669,6 +1688,7 @@ public void testFSHHighlightAllMvFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("tags", "tag"))
@@ -1686,11 +1706,12 @@ public void testFSHHighlightAllMvFragments() throws Exception {
         );
     }
 
-    public void testBoostingQuery() {
+    public void testBoostingQuery() throws InterruptedException {
         createIndex("test");
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -1702,11 +1723,12 @@ public void testBoostingQuery() {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testBoostingQueryTermVector() throws IOException {
+    public void testBoostingQueryTermVector() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1TermVectorMapping()));
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -1718,12 +1740,13 @@ public void testBoostingQueryTermVector() throws IOException {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testCommonTermsQuery() {
+    public void testCommonTermsQuery() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
@@ -1733,12 +1756,13 @@ public void testCommonTermsQuery() {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The <x>quick</x> <x>brown</x> fox jumps over the lazy dog"));
     }
 
-    public void testCommonTermsTermVector() throws IOException {
+    public void testCommonTermsTermVector() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1TermVectorMapping()));
         ensureGreen();
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
             .highlighter(highlight().field("field2").order("score").preTags("<x>").postTags("</x>"));
@@ -1764,6 +1788,7 @@ public void testPlainHighlightDifferentFragmenter() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchPhraseQuery("tags", "long tag"))
@@ -1816,12 +1841,13 @@ public void testPlainHighlightDifferentFragmenter() throws Exception {
         );
     }
 
-    public void testPlainHighlighterMultipleFields() {
+    public void testPlainHighlighterMultipleFields() throws InterruptedException {
         createIndex("test");
         ensureGreen();
 
         index("test", "type1", "1", "field1", "The <b>quick<b> brown fox", "field2", "The <b>slow<b> brown fox");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -1834,7 +1860,7 @@ public void testPlainHighlighterMultipleFields() {
         assertHighlight(response, 0, "field2", 0, 1, equalTo("The <b>slow<b> brown <2>fox</2>"));
     }
 
-    public void testFastVectorHighlighterMultipleFields() {
+    public void testFastVectorHighlighterMultipleFields() throws InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "field1",
@@ -1847,6 +1873,7 @@ public void testFastVectorHighlighterMultipleFields() {
 
         index("test", "type1", "1", "field1", "The <b>quick<b> brown fox", "field2", "The <b>slow<b> brown fox");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -1864,6 +1891,7 @@ public void testMissingStoredField() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource(jsonBuilder().startObject().field("field", "highlight").endObject()).get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // This query used to fail when the field to highlight was absent
         SearchResponse response = client().prepareSearch("test")
@@ -1904,6 +1932,7 @@ public void testNumericHighlighting() throws Exception {
             .setSource("text", "opensearch test", "byte", 25, "short", 42, "int", 100, "long", -1, "float", 3.2f, "double", 42.42)
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("text", "test"))
@@ -1926,6 +1955,7 @@ public void testResetTwice() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("text", "opensearch test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("text", "test"))
@@ -1935,7 +1965,7 @@ public void testResetTwice() throws Exception {
         assertHitCount(response, 1L);
     }
 
-    public void testHighlightUsesHighlightQuery() throws IOException {
+    public void testHighlightUsesHighlightQuery() throws IOException, InterruptedException {
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -1946,6 +1976,7 @@ public void testHighlightUsesHighlightQuery() throws IOException {
 
         index("test", "type1", "1", "text", "Testing the highlight query feature");
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         for (String type : ALL_TYPES) {
             HighlightBuilder.Field field = new HighlightBuilder.Field("text");
@@ -1981,7 +2012,11 @@ private static String randomStoreField() {
         return "";
     }
 
-    public void testHighlightNoMatchSize() throws IOException {
+    public void testHighlightNoMatchSize() throws IOException, InterruptedException {
+        assumeFalse(
+            "Concurrent search case muted pending fix: https://github.com/opensearch-project/OpenSearch/issues/10900",
+            internalCluster().clusterService().getClusterSettings().get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING)
+        );
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -1993,6 +2028,7 @@ public void testHighlightNoMatchSize() throws IOException {
         String text = "I am pretty long so some of me should get cut off. Second sentence";
         index("test", "type1", "1", "text", text);
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // When you don't set noMatchSize you don't get any results if there isn't anything to highlight.
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(21).numOfFragments(1).highlighterType("plain");
@@ -2091,7 +2127,11 @@ public void testHighlightNoMatchSize() throws IOException {
         assertNotHighlighted(response, 0, "text");
     }
 
-    public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
+    public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException, InterruptedException {
+        assumeFalse(
+            "Concurrent search case muted pending fix: https://github.com/opensearch-project/OpenSearch/issues/10900",
+            internalCluster().clusterService().getClusterSettings().get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING)
+        );
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -2104,6 +2144,7 @@ public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
         String text2 = "I am short";
         index("test", "type1", "1", "text", new String[] { text1, text2 });
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // The no match fragment should come from the first value of a multi-valued field
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(21)
@@ -2186,7 +2227,11 @@ public void testHighlightNoMatchSizeWithMultivaluedFields() throws IOException {
         assertNotHighlighted(response, 0, "text");
     }
 
-    public void testHighlightNoMatchSizeNumberOfFragments() throws IOException {
+    public void testHighlightNoMatchSizeNumberOfFragments() throws IOException, InterruptedException {
+        assumeFalse(
+            "Concurrent search case muted pending fix: https://github.com/opensearch-project/OpenSearch/issues/10900",
+            internalCluster().clusterService().getClusterSettings().get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING)
+        );
         assertAcked(
             prepareCreate("test").setMapping(
                 "text",
@@ -2200,6 +2245,7 @@ public void testHighlightNoMatchSizeNumberOfFragments() throws IOException {
         String text3 = "This is the fifth sentence";
         index("test", "type1", "1", "text", new String[] { text1, text2, text3 });
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // The no match fragment should come from the first value of a multi-valued field
         HighlightBuilder.Field field = new HighlightBuilder.Field("text").fragmentSize(1)
@@ -2243,6 +2289,7 @@ public void testPostingsHighlighter() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy quick dog")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "test"))
@@ -2320,6 +2367,7 @@ public void testPostingsHighlighterMultipleFields() throws Exception {
             "The <b>slow<b> brown fox. Second sentence."
         );
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test")
             .setQuery(QueryBuilders.matchQuery("field1", "fox"))
@@ -2344,6 +2392,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "fox"))
@@ -2376,6 +2425,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         source = searchSource().query(termQuery("field1", "fox"))
             .highlighter(highlight().field(new Field("field1").numOfFragments(0).preTags("<field1>").postTags("</field1>")));
@@ -2412,7 +2462,7 @@ public void testPostingsHighlighterNumberOfFragments() throws Exception {
         }
     }
 
-    public void testMultiMatchQueryHighlight() throws IOException {
+    public void testMultiMatchQueryHighlight() throws IOException, InterruptedException {
         XContentBuilder mapping = XContentFactory.jsonBuilder()
             .startObject()
             .startObject("properties")
@@ -2434,6 +2484,7 @@ public void testMultiMatchQueryHighlight() throws IOException {
             .setSource("field1", "The quick brown fox jumps over", "field2", "The quick brown fox jumps over")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         final int iters = scaledRandomIntBetween(20, 30);
         for (int i = 0; i < iters; i++) {
             String highlighterType = rarely() ? null : RandomPicks.randomFrom(random(), ALL_TYPES);
@@ -2479,6 +2530,7 @@ public void testPostingsHighlighterOrderByScore() throws Exception {
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(termQuery("field1", "sentence"))
@@ -2565,6 +2617,7 @@ public void testPostingsHighlighterMultiMapperWithStore() throws Exception {
         ensureGreen();
         client().prepareIndex("test").setId("1").setSource("title", "this is a test . Second sentence.").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse searchResponse = client().prepareSearch()
@@ -2623,6 +2676,7 @@ public void testPostingsHighlighterMultiMapperFromSource() throws Exception {
 
         client().prepareIndex("test").setId("1").setSource("title", "this is a test").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // simple search on body with standard analyzer with a simple field query
         SearchResponse searchResponse = client().prepareSearch()
@@ -2672,13 +2726,14 @@ public void testPostingsHighlighterShouldFailIfNoOffsets() throws Exception {
         assertNoFailures(search);
     }
 
-    public void testPostingsHighlighterBoostingQuery() throws IOException {
+    public void testPostingsHighlighterBoostingQuery() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1PostingsffsetsMapping()));
         ensureGreen();
         client().prepareIndex("test")
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2689,7 +2744,7 @@ public void testPostingsHighlighterBoostingQuery() throws IOException {
         assertHighlight(searchResponse, 0, "field2", 0, 1, equalTo("The quick <x>brown</x> fox jumps over the lazy dog! Second sentence."));
     }
 
-    public void testPostingsHighlighterCommonTermsQuery() throws IOException {
+    public void testPostingsHighlighterCommonTermsQuery() throws IOException, InterruptedException {
         assertAcked(prepareCreate("test").setMapping(type1PostingsffsetsMapping()));
         ensureGreen();
 
@@ -2697,6 +2752,7 @@ public void testPostingsHighlighterCommonTermsQuery() throws IOException {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(commonTermsQuery("field2", "quick brown").cutoffFrequency(100))
@@ -2738,6 +2794,7 @@ public void testPostingsHighlighterPrefixQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         logger.info("--> highlighting and searching on field2");
 
         SearchSourceBuilder source = searchSource().query(prefixQuery("field2", "qui")).highlighter(highlight().field("field2"));
@@ -2760,6 +2817,7 @@ public void testPostingsHighlighterFuzzyQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(fuzzyQuery("field2", "quck")).highlighter(highlight().field("field2"));
@@ -2783,6 +2841,7 @@ public void testPostingsHighlighterRegexpQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(regexpQuery("field2", "qu[a-l]+k")).highlighter(highlight().field("field2"));
@@ -2806,6 +2865,7 @@ public void testPostingsHighlighterWildcardQuery() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(wildcardQuery("field2", "qui*")).highlighter(highlight().field("field2"));
@@ -2840,6 +2900,7 @@ public void testPostingsHighlighterTermRangeQuery() throws Exception {
 
         client().prepareIndex("test").setSource("field1", "this is a test", "field2", "aaab").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(rangeQuery("field2").gte("aaaa").lt("zzzz"))
@@ -2857,6 +2918,7 @@ public void testPostingsHighlighterQueryString() throws Exception {
             .setSource("field1", "this is a test", "field2", "The quick brown fox jumps over the lazy dog! Second sentence.")
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field2");
         SearchSourceBuilder source = searchSource().query(queryStringQuery("qui*").defaultField("field2"))
@@ -2878,6 +2940,7 @@ public void testPostingsHighlighterRegexpQueryWithinConstantScoreQuery() throws
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(constantScoreQuery(regexpQuery("field1", "pho[a-z]+")))
@@ -2892,6 +2955,7 @@ public void testPostingsHighlighterMultiTermQueryMultipleLevels() throws Excepti
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2909,6 +2973,7 @@ public void testPostingsHighlighterPrefixQueryWithinBooleanQuery() throws Except
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -2924,6 +2989,7 @@ public void testPostingsHighlighterQueryStringWithinFilteredQuery() throws Excep
 
         client().prepareIndex("test").setSource("field1", "The photography word will get highlighted").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> highlighting and searching on field1");
         SearchSourceBuilder source = searchSource().query(
@@ -3028,7 +3094,7 @@ public void testFastVectorHighlighterPhraseBoost() throws Exception {
      * because it doesn't support the concept of terms having a different weight based on position.
      * @param highlighterType highlighter to test
      */
-    private void phraseBoostTestCase(String highlighterType) {
+    private void phraseBoostTestCase(String highlighterType) throws InterruptedException {
         ensureGreen();
         StringBuilder text = new StringBuilder();
         text.append("words words junk junk junk junk junk junk junk junk highlight junk junk junk junk together junk\n");
@@ -3041,6 +3107,7 @@ private void phraseBoostTestCase(String highlighterType) {
         }
         index("test", "type1", "1", "field1", text.toString());
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         // Match queries
         phraseBoostTestCaseForClauses(
@@ -3109,7 +3176,7 @@ private <P extends AbstractQueryBuilder<P>> void phraseBoostTestCaseForClauses(
         assertHighlight(response, 0, "field1", 0, 1, highlightedMatcher);
     }
 
-    public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOException {
+    public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOException, InterruptedException {
         // check that we do not get an exception for geo_point fields in case someone tries to highlight
         // it accidentially with a wildcard
         // see https://github.com/elastic/elasticsearch/issues/17537
@@ -3133,6 +3200,7 @@ public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOExcepti
             .setSource(jsonBuilder().startObject().field("text", "Arbitrary text field which will should not cause a failure").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         String highlighterType = randomFrom(ALL_TYPES);
         QueryBuilder query = QueryBuilders.boolQuery()
             .should(
@@ -3150,7 +3218,7 @@ public void testGeoFieldHighlightingWithDifferentHighlighters() throws IOExcepti
         assertThat(search.getHits().getAt(0).getHighlightFields().get("text").fragments().length, equalTo(1));
     }
 
-    public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException {
+    public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException, InterruptedException {
         // same as above but in this example the query gets rewritten during highlighting
         // see https://github.com/elastic/elasticsearch/issues/17537#issuecomment-244939633
         XContentBuilder mappings = jsonBuilder();
@@ -3177,6 +3245,7 @@ public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException
             )
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         QueryBuilder query = QueryBuilders.functionScoreQuery(
             QueryBuilders.boolQuery()
@@ -3192,7 +3261,7 @@ public void testGeoFieldHighlightingWhenQueryGetsRewritten() throws IOException
         assertThat(search.getHits().getTotalHits().value, equalTo(1L));
     }
 
-    public void testKeywordFieldHighlighting() throws IOException {
+    public void testKeywordFieldHighlighting() throws IOException, InterruptedException {
         // check that keyword highlighting works
         XContentBuilder mappings = jsonBuilder();
         mappings.startObject();
@@ -3205,6 +3274,7 @@ public void testKeywordFieldHighlighting() throws IOException {
             .setSource(jsonBuilder().startObject().field("keyword_field", "some text").endObject())
             .get();
         refresh();
+        indexRandomForConcurrentSearch("test");
         SearchResponse search = client().prepareSearch()
             .setSource(
                 new SearchSourceBuilder().query(QueryBuilders.matchQuery("keyword_field", "some text"))
@@ -3238,6 +3308,7 @@ public void testCopyToFields() throws Exception {
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
 
+        indexRandomForConcurrentSearch("test");
         SearchResponse response = client().prepareSearch()
             .setQuery(matchQuery("foo_copy", "brown"))
             .highlighter(new HighlightBuilder().field(new Field("foo_copy")))
@@ -3287,7 +3358,7 @@ public void testACopyFieldWithNestedQuery() throws Exception {
             )
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
-
+        indexRandomForConcurrentSearch("test");
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(nestedQuery("foo", matchQuery("foo.text", "brown cow"), ScoreMode.None))
             .highlighter(new HighlightBuilder().field(new Field("foo_text").highlighterType("fvh")).requireFieldMatch(false))
@@ -3305,6 +3376,7 @@ public void testFunctionScoreQueryHighlight() throws Exception {
             .setSource(jsonBuilder().startObject().field("text", "brown").endObject())
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(new FunctionScoreQueryBuilder(QueryBuilders.prefixQuery("text", "bro")))
@@ -3322,6 +3394,7 @@ public void testFiltersFunctionScoreQueryHighlight() throws Exception {
             .setSource(jsonBuilder().startObject().field("text", "brown").field("enable", "yes").endObject())
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
         FunctionScoreQueryBuilder.FilterFunctionBuilder filterBuilder = new FunctionScoreQueryBuilder.FilterFunctionBuilder(
             QueryBuilders.termQuery("enable", "yes"),
             new RandomScoreFunctionBuilder()
@@ -3420,6 +3493,7 @@ public void testWithNestedQuery() throws Exception {
             )
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String type : new String[] { "unified", "plain" }) {
             SearchResponse searchResponse = client().prepareSearch()
@@ -3477,6 +3551,7 @@ public void testWithNormalizer() throws Exception {
             .setSource("keyword", "Hello World")
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String highlighterType : new String[] { "unified", "plain" }) {
             SearchResponse searchResponse = client().prepareSearch()
@@ -3499,6 +3574,7 @@ public void testDisableHighlightIdField() throws Exception {
             .setSource("keyword", "Hello World")
             .setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         for (String highlighterType : new String[] { "plain", "unified" }) {
             SearchResponse searchResponse = client().prepareSearch()
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java b/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
index 83dec7b27a897..656e7b2e366ed 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/nested/SimpleNestedIT.java
@@ -293,6 +293,7 @@ public void testMultiNested() throws Exception {
         refresh();
         // check the numDocs
         assertDocumentCount("test", 7);
+        indexRandomForConcurrentSearch("test");
 
         // do some multi nested queries
         SearchResponse searchResponse = client().prepareSearch("test")
@@ -485,6 +486,7 @@ public void testExplain() throws Exception {
             )
             .setRefreshPolicy(IMMEDIATE)
             .get();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch("test")
             .setQuery(nestedQuery("nested1", termQuery("nested1.n_field1", "n_value1"), ScoreMode.Total))
@@ -968,6 +970,10 @@ public void testNestedSortWithMultiLevelFiltering() throws Exception {
 
     // https://github.com/elastic/elasticsearch/issues/31554
     public void testLeakingSortValues() throws Exception {
+        assumeFalse(
+            "Concurrent search case muted pending fix: https://github.com/opensearch-project/OpenSearch/issues/11065",
+            internalCluster().clusterService().getClusterSettings().get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING)
+        );
         assertAcked(
             prepareCreate("test").setSettings(Settings.builder().put("number_of_shards", 1))
                 .setMapping(
@@ -1035,6 +1041,7 @@ public void testLeakingSortValues() throws Exception {
             .get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setQuery(termQuery("_id", 2))
@@ -1627,6 +1634,7 @@ public void testCheckFixedBitSetCache() throws Exception {
         client().prepareIndex("test").setId("1").setSource("field", "value").get();
         refresh();
         ensureSearchable("test");
+        indexRandomForConcurrentSearch("test");
 
         // No nested mapping yet, there shouldn't be anything in the fixed bit set cache
         ClusterStatsResponse clusterStatsResponse = client().admin().cluster().prepareClusterStats().get();
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
index 4a178e7066846..8ae652082f653 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/pit/DeletePitMultiNodeIT.java
@@ -309,7 +309,11 @@ public void testDeleteWhileSearch() throws Exception {
     private void verifySearchContextMissingException(ShardSearchFailure[] failures) {
         for (ShardSearchFailure failure : failures) {
             Throwable cause = ExceptionsHelper.unwrapCause(failure.getCause());
-            assertTrue(failure.toString(), cause instanceof SearchContextMissingException);
+            if (failure.toString().contains("reader_context is already closed can't increment refCount current count")) {
+                // this is fine, expected search error when context is already deleted
+            } else {
+                assertTrue(failure.toString(), cause instanceof SearchContextMissingException);
+            }
         }
     }
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java b/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
index e42f12709c948..a3432bfe7e3e4 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/pit/PitMultiNodeIT.java
@@ -100,6 +100,7 @@ public void clearIndex() {
     public void testPit() throws Exception {
         CreatePitRequest request = new CreatePitRequest(TimeValue.timeValueDays(1), true);
         request.setIndices(new String[] { "index" });
+        indexRandomForConcurrentSearch("index");
         ActionFuture<CreatePitResponse> execute = client().execute(CreatePitAction.INSTANCE, request);
         CreatePitResponse pitResponse = execute.get();
         SearchResponse searchResponse = client().prepareSearch("index")
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java b/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
index 425764b1c88d2..97fe05f5b9747 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/preference/SearchPreferenceIT.java
@@ -52,7 +52,6 @@
 import org.opensearch.test.OpenSearchIntegTestCase;
 import org.opensearch.test.ParameterizedOpenSearchIntegTestCase;
 
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -99,7 +98,7 @@ public Settings nodeSettings(int nodeOrdinal) {
     }
 
     // see #2896
-    public void testStopOneNodePreferenceWithRedState() throws IOException {
+    public void testStopOneNodePreferenceWithRedState() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 Settings.builder().put("index.number_of_shards", cluster().numDataNodes() + 2).put("index.number_of_replicas", 0)
@@ -110,6 +109,7 @@ public void testStopOneNodePreferenceWithRedState() throws IOException {
             client().prepareIndex("test").setId("" + i).setSource("field1", "value1").get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test");
         internalCluster().stopRandomDataNode();
         client().admin().cluster().prepareHealth().setWaitForStatus(ClusterHealthStatus.RED).get();
         String[] preferences = new String[] {
@@ -138,7 +138,7 @@ public void testStopOneNodePreferenceWithRedState() throws IOException {
         assertThat("_only_local", searchResponse.getFailedShards(), greaterThanOrEqualTo(0));
     }
 
-    public void testNoPreferenceRandom() {
+    public void testNoPreferenceRandom() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 // this test needs at least a replica to make sure two consecutive searches go to two different copies of the same data
@@ -149,6 +149,7 @@ public void testNoPreferenceRandom() {
 
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         final Client client = internalCluster().smartClient();
         SearchResponse searchResponse = client.prepareSearch("test").setQuery(matchAllQuery()).get();
@@ -201,7 +202,7 @@ public void testThatSpecifyingNonExistingNodesReturnsUsefulError() {
         }
     }
 
-    public void testNodesOnlyRandom() {
+    public void testNodesOnlyRandom() throws Exception {
         assertAcked(
             prepareCreate("test").setSettings(
                 // this test needs at least a replica to make sure two consecutive searches go to two different copies of the same data
@@ -211,6 +212,7 @@ public void testNodesOnlyRandom() {
         ensureGreen();
         client().prepareIndex("test").setSource("field1", "value1").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         final Client client = internalCluster().smartClient();
         // multiple wildchar to cover multi-param usecase
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
index 099eb934f4f4d..1ca5859f23bca 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/QueryStringIT.java
@@ -186,6 +186,7 @@ public void testDocWithAllTypes() throws Exception {
         String docBody = copyToStringFromClasspath("/org/opensearch/search/query/all-example-document.json");
         reqs.add(client().prepareIndex("test").setId("1").setSource(docBody, MediaTypeRegistry.JSON));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(queryStringQuery("foo")).get();
         assertHits(resp.getHits(), "1");
@@ -225,6 +226,7 @@ public void testKeywordWithWhitespace() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f1", "foo bar"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(queryStringQuery("foo")).get();
         assertHits(resp.getHits(), "3");
@@ -245,6 +247,7 @@ public void testRegexCaseInsensitivity() throws Exception {
         indexRequests.add(client().prepareIndex("messages").setId("1").setSource("message", "message: this is a TLS handshake"));
         indexRequests.add(client().prepareIndex("messages").setId("2").setSource("message", "message: this is a tcp handshake"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("messages");
 
         SearchResponse response = client().prepareSearch("messages").setQuery(queryStringQuery("/TLS/").defaultField("message")).get();
         assertNoFailures(response);
@@ -282,6 +285,7 @@ public void testAllFields() throws Exception {
         List<IndexRequestBuilder> reqs = new ArrayList<>();
         reqs.add(client().prepareIndex("test_1").setId("1").setSource("f1", "foo", "f2", "eggplant"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test_1");
 
         SearchResponse resp = client().prepareSearch("test_1")
             .setQuery(queryStringQuery("foo eggplant").defaultOperator(Operator.AND))
@@ -374,6 +378,7 @@ public void testLimitOnExpandedFields() throws Exception {
 
         client().prepareIndex("testindex").setId("1").setSource("field_A0", "foo bar baz").get();
         refresh();
+        indexRandomForConcurrentSearch("testindex");
 
         // single field shouldn't trigger the limit
         doAssertOneHitForQueryString("field_A0:foo");
@@ -465,6 +470,7 @@ public void testFieldAliasOnDisallowedFieldType() throws Exception {
         List<IndexRequestBuilder> indexRequests = new ArrayList<>();
         indexRequests.add(client().prepareIndex("test").setId("1").setSource("f3", "text", "f2", "one"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         // The wildcard field matches aliases for both a text and geo_point field.
         // By default, the geo_point field should be ignored when building the query.
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
index 7ba582811bbc2..55029712a061c 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/ScriptScoreQueryIT.java
@@ -109,13 +109,14 @@ protected Map<String, Function<Map<String, Object>, Object>> pluginScripts() {
     // 1) only matched docs retrieved
     // 2) score is calculated based on a script with params
     // 3) min score applied
-    public void testScriptScore() {
+    public void testScriptScore() throws Exception {
         assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
         int docCount = 10;
         for (int i = 1; i <= docCount; i++) {
             client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + (i % 2), "field2", i).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test-index");
 
         Map<String, Object> params = new HashMap<>();
         params.put("param1", 0.1);
@@ -135,13 +136,14 @@ public void testScriptScore() {
         assertOrderedSearchHits(resp, "10", "8", "6");
     }
 
-    public void testScriptScoreBoolQuery() {
+    public void testScriptScoreBoolQuery() throws Exception {
         assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
         int docCount = 10;
         for (int i = 1; i <= docCount; i++) {
             client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + i, "field2", i).get();
         }
         refresh();
+        indexRandomForConcurrentSearch("test-index");
 
         Map<String, Object> params = new HashMap<>();
         params.put("param1", 0.1);
@@ -155,7 +157,7 @@ public void testScriptScoreBoolQuery() {
     }
 
     // test that when the internal query is rewritten script_score works well
-    public void testRewrittenQuery() {
+    public void testRewrittenQuery() throws Exception {
         assertAcked(
             prepareCreate("test-index2").setSettings(Settings.builder().put("index.number_of_shards", 1))
                 .setMapping("field1", "type=date", "field2", "type=double")
@@ -164,6 +166,7 @@ public void testRewrittenQuery() {
         client().prepareIndex("test-index2").setId("2").setSource("field1", "2019-10-01", "field2", 2).get();
         client().prepareIndex("test-index2").setId("3").setSource("field1", "2019-11-01", "field2", 3).get();
         refresh();
+        indexRandomForConcurrentSearch("test-index2");
 
         RangeQueryBuilder rangeQB = new RangeQueryBuilder("field1").from("2019-01-01"); // the query should be rewritten to from:null
         Map<String, Object> params = new HashMap<>();
@@ -174,7 +177,7 @@ public void testRewrittenQuery() {
         assertOrderedSearchHits(resp, "3", "2", "1");
     }
 
-    public void testDisallowExpensiveQueries() {
+    public void testDisallowExpensiveQueries() throws Exception {
         try {
             assertAcked(prepareCreate("test-index").setMapping("field1", "type=text", "field2", "type=double"));
             int docCount = 10;
@@ -182,6 +185,7 @@ public void testDisallowExpensiveQueries() {
                 client().prepareIndex("test-index").setId("" + i).setSource("field1", "text" + (i % 2), "field2", i).get();
             }
             refresh();
+            indexRandomForConcurrentSearch("test-index");
 
             Map<String, Object> params = new HashMap<>();
             params.put("param1", 0.1);
diff --git a/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java b/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
index 384d2b7423e66..017d28ef3a2a6 100644
--- a/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/search/query/SimpleQueryStringIT.java
@@ -150,6 +150,7 @@ public void testSimpleQueryString() throws ExecutionException, InterruptedExcept
             client().prepareIndex("test").setId("5").setSource("body", "quux baz spaghetti"),
             client().prepareIndex("test").setId("6").setSource("otherbody", "spaghetti")
         );
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHitCount(searchResponse, 3L);
@@ -199,6 +200,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
             client().prepareIndex("test").setId("3").setSource("body", "foo bar"),
             client().prepareIndex("test").setId("4").setSource("body", "foo baz bar")
         );
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> query 1");
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar").minimumShouldMatch("2")).get();
@@ -235,6 +237,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
             client().prepareIndex("test").setId("7").setSource("body2", "foo bar", "other", "foo"),
             client().prepareIndex("test").setId("8").setSource("body2", "foo baz bar", "other", "foo")
         );
+        indexRandomForConcurrentSearch("test");
 
         logger.info("--> query 5");
         searchResponse = client().prepareSearch()
@@ -256,7 +259,7 @@ public void testSimpleQueryStringMinimumShouldMatch() throws Exception {
         assertSearchHits(searchResponse, "6", "7", "8");
     }
 
-    public void testNestedFieldSimpleQueryString() throws IOException {
+    public void testNestedFieldSimpleQueryString() throws Exception {
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -275,6 +278,7 @@ public void testNestedFieldSimpleQueryString() throws IOException {
         );
         client().prepareIndex("test").setId("1").setSource("body", "foo bar baz").get();
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("foo bar baz").field("body")).get();
         assertHitCount(searchResponse, 1L);
@@ -359,6 +363,8 @@ public void testSimpleQueryStringLenient() throws ExecutionException, Interrupte
             client().prepareIndex("test2").setId("10").setSource("field", 5)
         );
         refresh();
+        indexRandomForConcurrentSearch("test1");
+        indexRandomForConcurrentSearch("test2");
 
         SearchResponse searchResponse = client().prepareSearch()
             .setAllowPartialSearchResults(true)
@@ -419,6 +425,7 @@ public void testSimpleQueryStringUsesFieldAnalyzer() throws Exception {
         client().prepareIndex("test").setId("2").setSource("foo", 234, "bar", "bcd").get();
 
         refresh();
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse searchResponse = client().prepareSearch().setQuery(simpleQueryStringQuery("123").field("foo").field("bar")).get();
         assertHitCount(searchResponse, 1L);
@@ -469,6 +476,7 @@ public void testBasicAllQuery() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f2", "Bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f3", "foo bar baz"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHitCount(resp, 2L);
@@ -492,6 +500,7 @@ public void testWithDate() throws Exception {
         reqs.add(client().prepareIndex("test").setId("1").setSource("f1", "foo", "f_date", "2015/09/02"));
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar", "f_date", "2015/09/01"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHits(resp.getHits(), "1", "2");
@@ -523,6 +532,7 @@ public void testWithLotsOfTypes() throws Exception {
             client().prepareIndex("test").setId("2").setSource("f1", "bar", "f_date", "2015/09/01", "f_float", "1.8", "f_ip", "127.0.0.2")
         );
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo bar")).get();
         assertHits(resp.getHits(), "1", "2");
@@ -550,6 +560,7 @@ public void testDocWithAllTypes() throws Exception {
         String docBody = copyToStringFromClasspath("/org/opensearch/search/query/all-example-document.json");
         reqs.add(client().prepareIndex("test").setId("1").setSource(docBody, MediaTypeRegistry.JSON));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHits(resp.getHits(), "1");
@@ -596,6 +607,7 @@ public void testKeywordWithWhitespace() throws Exception {
         reqs.add(client().prepareIndex("test").setId("2").setSource("f1", "bar"));
         reqs.add(client().prepareIndex("test").setId("3").setSource("f1", "foo bar"));
         indexRandom(true, false, reqs);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse resp = client().prepareSearch("test").setQuery(simpleQueryStringQuery("foo")).get();
         assertHits(resp.getHits(), "3");
@@ -663,6 +675,7 @@ public void testFieldAlias() throws Exception {
         indexRequests.add(client().prepareIndex("test").setId("2").setSource("f3", "value", "f2", "two"));
         indexRequests.add(client().prepareIndex("test").setId("3").setSource("f3", "another value", "f2", "three"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setQuery(simpleQueryStringQuery("value").field("f3_alias")).get();
 
@@ -681,6 +694,7 @@ public void testFieldAliasWithWildcardField() throws Exception {
         indexRequests.add(client().prepareIndex("test").setId("2").setSource("f3", "value", "f2", "two"));
         indexRequests.add(client().prepareIndex("test").setId("3").setSource("f3", "another value", "f2", "three"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         SearchResponse response = client().prepareSearch("test").setQuery(simpleQueryStringQuery("value").field("f3_*")).get();
 
@@ -697,6 +711,7 @@ public void testFieldAliasOnDisallowedFieldType() throws Exception {
         List<IndexRequestBuilder> indexRequests = new ArrayList<>();
         indexRequests.add(client().prepareIndex("test").setId("1").setSource("f3", "text", "f2", "one"));
         indexRandom(true, false, indexRequests);
+        indexRandomForConcurrentSearch("test");
 
         // The wildcard field matches aliases for both a text and boolean field.
         // By default, the boolean field should be ignored when building the query.
diff --git a/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java
index 9cbe2d2ffcb7d..8fe1be610f9af 100644
--- a/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java
+++ b/server/src/main/java/org/opensearch/action/search/SearchQueryCategorizer.java
@@ -75,7 +75,7 @@ private void logQueryShape(QueryBuilder topLevelQueryBuilder) {
         }
         QueryShapeVisitor shapeVisitor = new QueryShapeVisitor();
         topLevelQueryBuilder.visit(shapeVisitor);
-        log.debug("Query shape : {}", shapeVisitor.prettyPrintTree("  "));
+        log.trace("Query shape : {}", shapeVisitor.prettyPrintTree("  "));
     }
 
 }
diff --git a/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java b/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
index a6fb8453af4ff..16b7e4810b130 100644
--- a/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
+++ b/server/src/main/java/org/opensearch/action/search/TransportSearchAction.java
@@ -506,24 +506,51 @@ private void executeRequest(
         ActionListener<SearchResponse> listener;
         try {
             searchRequest = searchPipelineService.resolvePipeline(originalSearchRequest);
-            listener = ActionListener.wrap(
-                r -> originalListener.onResponse(searchRequest.transformResponse(r)),
-                originalListener::onFailure
-            );
+            listener = searchRequest.transformResponseListener(originalListener);
         } catch (Exception e) {
             originalListener.onFailure(e);
             return;
         }
 
-        if (searchQueryMetricsEnabled) {
-            try {
-                searchQueryCategorizer.categorize(searchRequest.source());
-            } catch (Exception e) {
-                logger.error("Error while trying to categorize the query.", e);
+        ActionListener<SearchRequest> requestTransformListener = ActionListener.wrap(sr -> {
+            if (searchQueryMetricsEnabled) {
+                try {
+                    searchQueryCategorizer.categorize(sr.source());
+                } catch (Exception e) {
+                    logger.error("Error while trying to categorize the query.", e);
+                }
             }
-        }
 
-        ActionListener<SearchSourceBuilder> rewriteListener = ActionListener.wrap(source -> {
+            ActionListener<SearchSourceBuilder> rewriteListener = buildRewriteListener(
+                sr,
+                task,
+                timeProvider,
+                searchAsyncActionProvider,
+                listener,
+                searchRequestOperationsListener
+            );
+            if (sr.source() == null) {
+                rewriteListener.onResponse(sr.source());
+            } else {
+                Rewriteable.rewriteAndFetch(
+                    sr.source(),
+                    searchService.getRewriteContext(timeProvider::getAbsoluteStartMillis),
+                    rewriteListener
+                );
+            }
+        }, listener::onFailure);
+        searchRequest.transformRequest(requestTransformListener);
+    }
+
+    private ActionListener<SearchSourceBuilder> buildRewriteListener(
+        SearchRequest searchRequest,
+        Task task,
+        SearchTimeProvider timeProvider,
+        SearchAsyncActionProvider searchAsyncActionProvider,
+        ActionListener<SearchResponse> listener,
+        SearchRequestOperationsListener searchRequestOperationsListener
+    ) {
+        return ActionListener.wrap(source -> {
             if (source != searchRequest.source()) {
                 // only set it if it changed - we don't allow null values to be set but it might be already null. this way we catch
                 // situations when source is rewritten to null due to a bug
@@ -634,15 +661,6 @@ private void executeRequest(
                 }
             }
         }, listener::onFailure);
-        if (searchRequest.source() == null) {
-            rewriteListener.onResponse(searchRequest.source());
-        } else {
-            Rewriteable.rewriteAndFetch(
-                searchRequest.source(),
-                searchService.getRewriteContext(timeProvider::getAbsoluteStartMillis),
-                rewriteListener
-            );
-        }
     }
 
     static boolean shouldMinimizeRoundtrips(SearchRequest searchRequest) {
diff --git a/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java b/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java
index 1dc20e564ade2..4d466c4b3ad73 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/PersistedStateStats.java
@@ -25,7 +25,7 @@
  * @opensearch.internal
  */
 public class PersistedStateStats implements Writeable, ToXContentObject {
-    private String statsName;
+    private final String statsName;
     private AtomicLong totalTimeInMillis = new AtomicLong(0);
     private AtomicLong failedCount = new AtomicLong(0);
     private AtomicLong successCount = new AtomicLong(0);
@@ -37,6 +37,7 @@ public PersistedStateStats(String statsName) {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
+        out.writeString(statsName);
         out.writeVLong(successCount.get());
         out.writeVLong(failedCount.get());
         out.writeVLong(totalTimeInMillis.get());
@@ -53,6 +54,7 @@ public void writeTo(StreamOutput out) throws IOException {
     }
 
     public PersistedStateStats(StreamInput in) throws IOException {
+        this.statsName = in.readString();
         this.successCount = new AtomicLong(in.readVLong());
         this.failedCount = new AtomicLong(in.readVLong());
         this.totalTimeInMillis = new AtomicLong(in.readVLong());
@@ -113,6 +115,10 @@ protected void addToExtendedFields(String extendedField, AtomicLong extendedFiel
         this.extendedFields.put(extendedField, extendedFieldValue);
     }
 
+    public String getStatsName() {
+        return statsName;
+    }
+
     /**
      * Fields for parsing and toXContent
      *
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
index 78a22fe11f072..8d76a39712ee3 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
@@ -1252,7 +1252,6 @@ List<String> getIndexSettingsValidationErrors(
         if (forbidPrivateIndexSettings) {
             validationErrors.addAll(validatePrivateSettingsNotExplicitlySet(settings, indexScopedSettings));
         }
-        validateIndexReplicationTypeSettings(settings, clusterService.getClusterSettings()).ifPresent(validationErrors::add);
         if (indexName.isEmpty() || indexName.get().charAt(0) != '.') {
             // Apply aware replica balance validation only to non system indices
             int replicaCount = settings.getAsInt(
@@ -1307,24 +1306,6 @@ private static List<String> validateIndexCustomPath(Settings settings, @Nullable
         return validationErrors;
     }
 
-    /**
-     * Validates {@code index.replication.type} is not set if {@code cluster.restrict.index.replication_type} is set to true.
-     *
-     * @param requestSettings settings passed in during index create request
-     * @param clusterSettings cluster setting
-     */
-    private static Optional<String> validateIndexReplicationTypeSettings(Settings requestSettings, ClusterSettings clusterSettings) {
-        if (requestSettings.hasValue(SETTING_REPLICATION_TYPE)
-            && clusterSettings.get(IndicesService.CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING)) {
-            return Optional.of(
-                "index setting [index.replication.type] is not allowed to be set as ["
-                    + IndicesService.CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING.getKey()
-                    + "=true]"
-            );
-        }
-        return Optional.empty();
-    }
-
     /**
      * Validates the settings and mappings for shrinking an index.
      *
diff --git a/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java b/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java
deleted file mode 100644
index 47e182b3caf84..0000000000000
--- a/server/src/main/java/org/opensearch/common/rounding/DateTimeUnit.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.OpenSearchException;
-import org.opensearch.common.joda.Joda;
-import org.joda.time.DateTimeField;
-import org.joda.time.DateTimeZone;
-import org.joda.time.chrono.ISOChronology;
-
-import java.util.function.Function;
-
-/**
- * Main date time unit class.
- *
- * @opensearch.internal
- */
-public enum DateTimeUnit {
-
-    WEEK_OF_WEEKYEAR((byte) 1, tz -> ISOChronology.getInstance(tz).weekOfWeekyear()),
-    YEAR_OF_CENTURY((byte) 2, tz -> ISOChronology.getInstance(tz).yearOfCentury()),
-    QUARTER((byte) 3, tz -> Joda.QuarterOfYear.getField(ISOChronology.getInstance(tz))),
-    MONTH_OF_YEAR((byte) 4, tz -> ISOChronology.getInstance(tz).monthOfYear()),
-    DAY_OF_MONTH((byte) 5, tz -> ISOChronology.getInstance(tz).dayOfMonth()),
-    HOUR_OF_DAY((byte) 6, tz -> ISOChronology.getInstance(tz).hourOfDay()),
-    MINUTES_OF_HOUR((byte) 7, tz -> ISOChronology.getInstance(tz).minuteOfHour()),
-    SECOND_OF_MINUTE((byte) 8, tz -> ISOChronology.getInstance(tz).secondOfMinute());
-
-    private final byte id;
-    private final Function<DateTimeZone, DateTimeField> fieldFunction;
-
-    DateTimeUnit(byte id, Function<DateTimeZone, DateTimeField> fieldFunction) {
-        this.id = id;
-        this.fieldFunction = fieldFunction;
-    }
-
-    public byte id() {
-        return id;
-    }
-
-    /**
-     * @return the {@link DateTimeField} for the provided {@link DateTimeZone} for this time unit
-     */
-    public DateTimeField field(DateTimeZone tz) {
-        return fieldFunction.apply(tz);
-    }
-
-    public static DateTimeUnit resolve(byte id) {
-        switch (id) {
-            case 1:
-                return WEEK_OF_WEEKYEAR;
-            case 2:
-                return YEAR_OF_CENTURY;
-            case 3:
-                return QUARTER;
-            case 4:
-                return MONTH_OF_YEAR;
-            case 5:
-                return DAY_OF_MONTH;
-            case 6:
-                return HOUR_OF_DAY;
-            case 7:
-                return MINUTES_OF_HOUR;
-            case 8:
-                return SECOND_OF_MINUTE;
-            default:
-                throw new OpenSearchException("Unknown date time unit id [" + id + "]");
-        }
-    }
-}
diff --git a/server/src/main/java/org/opensearch/common/rounding/Rounding.java b/server/src/main/java/org/opensearch/common/rounding/Rounding.java
deleted file mode 100644
index 41e808b64f7d9..0000000000000
--- a/server/src/main/java/org/opensearch/common/rounding/Rounding.java
+++ /dev/null
@@ -1,459 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.OpenSearchException;
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.core.common.io.stream.StreamInput;
-import org.opensearch.core.common.io.stream.StreamOutput;
-import org.opensearch.core.common.io.stream.Writeable;
-import org.joda.time.DateTimeField;
-import org.joda.time.DateTimeZone;
-import org.joda.time.IllegalInstantException;
-
-import java.io.IOException;
-import java.util.Objects;
-
-/**
- * A strategy for rounding long values.
- * <p>
- * Use the java based Rounding class where applicable
- *
- * @opensearch.internal
- */
-@Deprecated
-public abstract class Rounding implements Writeable {
-
-    public abstract byte id();
-
-    /**
-     * Rounds the given value.
-     */
-    public abstract long round(long value);
-
-    /**
-     * Given the rounded value (which was potentially generated by {@link #round(long)}, returns the next rounding value. For example, with
-     * interval based rounding, if the interval is 3, {@code nextRoundValue(6) = 9 }.
-     *
-     * @param value The current rounding value
-     * @return      The next rounding value;
-     */
-    public abstract long nextRoundingValue(long value);
-
-    @Override
-    public abstract boolean equals(Object obj);
-
-    @Override
-    public abstract int hashCode();
-
-    public static Builder builder(DateTimeUnit unit) {
-        return new Builder(unit);
-    }
-
-    public static Builder builder(TimeValue interval) {
-        return new Builder(interval);
-    }
-
-    /**
-     * Builder for rounding
-     *
-     * @opensearch.internal
-     */
-    public static class Builder {
-
-        private final DateTimeUnit unit;
-        private final long interval;
-
-        private DateTimeZone timeZone = DateTimeZone.UTC;
-
-        public Builder(DateTimeUnit unit) {
-            this.unit = unit;
-            this.interval = -1;
-        }
-
-        public Builder(TimeValue interval) {
-            this.unit = null;
-            if (interval.millis() < 1) throw new IllegalArgumentException("Zero or negative time interval not supported");
-            this.interval = interval.millis();
-        }
-
-        public Builder timeZone(DateTimeZone timeZone) {
-            if (timeZone == null) {
-                throw new IllegalArgumentException("Setting null as timezone is not supported");
-            }
-            this.timeZone = timeZone;
-            return this;
-        }
-
-        public Rounding build() {
-            Rounding timeZoneRounding;
-            if (unit != null) {
-                timeZoneRounding = new TimeUnitRounding(unit, timeZone);
-            } else {
-                timeZoneRounding = new TimeIntervalRounding(interval, timeZone);
-            }
-            return timeZoneRounding;
-        }
-    }
-
-    /**
-     * Rounding time units
-     *
-     * @opensearch.internal
-     */
-    static class TimeUnitRounding extends Rounding {
-
-        static final byte ID = 1;
-
-        private final DateTimeUnit unit;
-        private final DateTimeField field;
-        private final DateTimeZone timeZone;
-        private final boolean unitRoundsToMidnight;
-
-        TimeUnitRounding(DateTimeUnit unit, DateTimeZone timeZone) {
-            this.unit = unit;
-            this.field = unit.field(timeZone);
-            unitRoundsToMidnight = this.field.getDurationField().getUnitMillis() > 60L * 60L * 1000L;
-            this.timeZone = timeZone;
-        }
-
-        TimeUnitRounding(StreamInput in) throws IOException {
-            unit = DateTimeUnit.resolve(in.readByte());
-            timeZone = DateTimeZone.forID(in.readString());
-            field = unit.field(timeZone);
-            unitRoundsToMidnight = field.getDurationField().getUnitMillis() > 60L * 60L * 1000L;
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        /**
-         * @return The latest timestamp T which is strictly before utcMillis
-         * and such that timeZone.getOffset(T) != timeZone.getOffset(utcMillis).
-         * If there is no such T, returns Long.MAX_VALUE.
-         */
-        private long previousTransition(long utcMillis) {
-            final int offsetAtInputTime = timeZone.getOffset(utcMillis);
-            do {
-                // Some timezones have transitions that do not change the offset, so we have to
-                // repeatedly call previousTransition until a nontrivial transition is found.
-
-                long previousTransition = timeZone.previousTransition(utcMillis);
-                if (previousTransition == utcMillis) {
-                    // There are no earlier transitions
-                    return Long.MAX_VALUE;
-                }
-                assert previousTransition < utcMillis; // Progress was made
-                utcMillis = previousTransition;
-            } while (timeZone.getOffset(utcMillis) == offsetAtInputTime);
-
-            return utcMillis;
-        }
-
-        @Override
-        public long round(long utcMillis) {
-
-            // field.roundFloor() works as long as the offset doesn't change. It is worth getting this case out of the way first, as
-            // the calculations for fixing things near to offset changes are a little expensive and are unnecessary in the common case
-            // of working in UTC.
-            if (timeZone.isFixed()) {
-                return field.roundFloor(utcMillis);
-            }
-
-            // When rounding to hours we consider any local time of the form 'xx:00:00' as rounded, even though this gives duplicate
-            // bucket names for the times when the clocks go back. Shorter units behave similarly. However, longer units round down to
-            // midnight, and on the days where there are two midnights we would rather pick the earlier one, so that buckets are
-            // uniquely identified by the date.
-            if (unitRoundsToMidnight) {
-                final long anyLocalStartOfDay = field.roundFloor(utcMillis);
-                // `anyLocalStartOfDay` is _supposed_ to be the Unix timestamp for the start of the day in question in the current time
-                // zone. Mostly this just means "midnight", which is fine, and on days with no local midnight it's the first time that
-                // does occur on that day which is also ok. However, on days with >1 local midnight this is _one_ of the midnights, but
-                // may not be the first. Check whether this is happening, and fix it if so.
-
-                final long previousTransition = previousTransition(anyLocalStartOfDay);
-
-                if (previousTransition == Long.MAX_VALUE) {
-                    // No previous transitions, so there can't be another earlier local midnight.
-                    return anyLocalStartOfDay;
-                }
-
-                final long currentOffset = timeZone.getOffset(anyLocalStartOfDay);
-                final long previousOffset = timeZone.getOffset(previousTransition);
-                assert currentOffset != previousOffset;
-
-                // NB we only assume interference from one previous transition. It's theoretically possible to have two transitions in
-                // quick succession, both of which have a midnight in them, but this doesn't appear to happen in the TZDB so (a) it's
-                // pointless to implement and (b) it won't be tested. I recognise that this comment is tempting fate and will likely
-                // cause this very situation to occur in the near future, and eagerly look forward to fixing this using a loop over
-                // previous transitions when it happens.
-
-                final long alsoLocalStartOfDay = anyLocalStartOfDay + currentOffset - previousOffset;
-                // `alsoLocalStartOfDay` is the Unix timestamp for the start of the day in question if the previous offset were in
-                // effect.
-
-                if (alsoLocalStartOfDay <= previousTransition) {
-                    // Therefore the previous offset _is_ in effect at `alsoLocalStartOfDay`, and it's earlier than anyLocalStartOfDay,
-                    // so this is the answer to use.
-                    return alsoLocalStartOfDay;
-                } else {
-                    // The previous offset is not in effect at `alsoLocalStartOfDay`, so the current offset must be.
-                    return anyLocalStartOfDay;
-                }
-
-            } else {
-                do {
-                    long rounded = field.roundFloor(utcMillis);
-
-                    // field.roundFloor() mostly works as long as the offset hasn't changed in [rounded, utcMillis], so look at where
-                    // the offset most recently changed.
-
-                    final long previousTransition = previousTransition(utcMillis);
-
-                    if (previousTransition == Long.MAX_VALUE || previousTransition < rounded) {
-                        // The offset did not change in [rounded, utcMillis], so roundFloor() worked as expected.
-                        return rounded;
-                    }
-
-                    // The offset _did_ change in [rounded, utcMillis]. Put differently, this means that none of the times in
-                    // [previousTransition+1, utcMillis] were rounded, so the rounded time must be <= previousTransition. This means
-                    // it's sufficient to try and round previousTransition down.
-                    assert previousTransition < utcMillis;
-                    utcMillis = previousTransition;
-                } while (true);
-            }
-        }
-
-        @Override
-        public long nextRoundingValue(long utcMillis) {
-            long floor = round(utcMillis);
-            // add one unit and round to get to next rounded value
-            long next = round(field.add(floor, 1));
-            if (next == floor) {
-                // in rare case we need to add more than one unit
-                next = round(field.add(floor, 2));
-            }
-            return next;
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            out.writeByte(unit.id());
-            out.writeString(timeZone.getID());
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(unit, timeZone);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            TimeUnitRounding other = (TimeUnitRounding) obj;
-            return Objects.equals(unit, other.unit) && Objects.equals(timeZone, other.timeZone);
-        }
-
-        @Override
-        public String toString() {
-            return "[" + timeZone + "][" + unit + "]";
-        }
-    }
-
-    /**
-     * Rounding time intervals
-     *
-     * @opensearch.internal
-     */
-    static class TimeIntervalRounding extends Rounding {
-
-        static final byte ID = 2;
-
-        private final long interval;
-        private final DateTimeZone timeZone;
-
-        TimeIntervalRounding(long interval, DateTimeZone timeZone) {
-            if (interval < 1) throw new IllegalArgumentException("Zero or negative time interval not supported");
-            this.interval = interval;
-            this.timeZone = timeZone;
-        }
-
-        TimeIntervalRounding(StreamInput in) throws IOException {
-            interval = in.readVLong();
-            timeZone = DateTimeZone.forID(in.readString());
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        @Override
-        public long round(long utcMillis) {
-            long timeLocal = timeZone.convertUTCToLocal(utcMillis);
-            long rounded = roundKey(timeLocal, interval) * interval;
-            long roundedUTC;
-            if (isInDSTGap(rounded) == false) {
-                roundedUTC = timeZone.convertLocalToUTC(rounded, true, utcMillis);
-                // check if we crossed DST transition, in this case we want the
-                // last rounded value before the transition
-                long transition = timeZone.previousTransition(utcMillis);
-                if (transition != utcMillis && transition > roundedUTC) {
-                    roundedUTC = round(transition - 1);
-                }
-            } else {
-                /*
-                 * Edge case where the rounded local time is illegal and landed
-                 * in a DST gap. In this case, we choose 1ms tick after the
-                 * transition date. We don't want the transition date itself
-                 * because those dates, when rounded themselves, fall into the
-                 * previous interval. This would violate the invariant that the
-                 * rounding operation should be idempotent.
-                 */
-                roundedUTC = timeZone.previousTransition(utcMillis) + 1;
-            }
-            return roundedUTC;
-        }
-
-        private static long roundKey(long value, long interval) {
-            if (value < 0) {
-                return (value - interval + 1) / interval;
-            } else {
-                return value / interval;
-            }
-        }
-
-        /**
-         * Determine whether the local instant is a valid instant in the given
-         * time zone. The logic for this is taken from
-         * {@link DateTimeZone#convertLocalToUTC(long, boolean)} for the
-         * `strict` mode case, but instead of throwing an
-         * {@link IllegalInstantException}, which is costly, we want to return a
-         * flag indicating that the value is illegal in that time zone.
-         */
-        private boolean isInDSTGap(long instantLocal) {
-            if (timeZone.isFixed()) {
-                return false;
-            }
-            // get the offset at instantLocal (first estimate)
-            int offsetLocal = timeZone.getOffset(instantLocal);
-            // adjust instantLocal using the estimate and recalc the offset
-            int offset = timeZone.getOffset(instantLocal - offsetLocal);
-            // if the offsets differ, we must be near a DST boundary
-            if (offsetLocal != offset) {
-                // determine if we are in the DST gap
-                long nextLocal = timeZone.nextTransition(instantLocal - offsetLocal);
-                if (nextLocal == (instantLocal - offsetLocal)) {
-                    nextLocal = Long.MAX_VALUE;
-                }
-                long nextAdjusted = timeZone.nextTransition(instantLocal - offset);
-                if (nextAdjusted == (instantLocal - offset)) {
-                    nextAdjusted = Long.MAX_VALUE;
-                }
-                if (nextLocal != nextAdjusted) {
-                    // we are in the DST gap
-                    return true;
-                }
-            }
-            return false;
-        }
-
-        @Override
-        public long nextRoundingValue(long time) {
-            long timeLocal = time;
-            timeLocal = timeZone.convertUTCToLocal(time);
-            long next = timeLocal + interval;
-            return timeZone.convertLocalToUTC(next, false);
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            out.writeVLong(interval);
-            out.writeString(timeZone.getID());
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(interval, timeZone);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            TimeIntervalRounding other = (TimeIntervalRounding) obj;
-            return Objects.equals(interval, other.interval) && Objects.equals(timeZone, other.timeZone);
-        }
-    }
-
-    /**
-     * Rounding streams
-     *
-     * @opensearch.internal
-     */
-    public static class Streams {
-
-        public static void write(Rounding rounding, StreamOutput out) throws IOException {
-            out.writeByte(rounding.id());
-            rounding.writeTo(out);
-        }
-
-        public static Rounding read(StreamInput in) throws IOException {
-            Rounding rounding;
-            byte id = in.readByte();
-            switch (id) {
-                case TimeUnitRounding.ID:
-                    rounding = new TimeUnitRounding(in);
-                    break;
-                case TimeIntervalRounding.ID:
-                    rounding = new TimeIntervalRounding(in);
-                    break;
-                default:
-                    throw new OpenSearchException("unknown rounding id [" + id + "]");
-            }
-            return rounding;
-        }
-
-    }
-
-}
diff --git a/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java b/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
index c2c6effc3336f..2bb81064c9c71 100644
--- a/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
+++ b/server/src/main/java/org/opensearch/common/settings/ClusterSettings.java
@@ -348,6 +348,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 HttpTransportSettings.SETTING_HTTP_MAX_WARNING_HEADER_SIZE,
                 HttpTransportSettings.SETTING_HTTP_MAX_INITIAL_LINE_LENGTH,
                 HttpTransportSettings.SETTING_HTTP_READ_TIMEOUT,
+                HttpTransportSettings.SETTING_HTTP_CONNECT_TIMEOUT,
                 HttpTransportSettings.SETTING_HTTP_RESET_COOKIES,
                 HttpTransportSettings.OLD_SETTING_HTTP_TCP_NO_DELAY,
                 HttpTransportSettings.SETTING_HTTP_TCP_NO_DELAY,
@@ -684,14 +685,14 @@ public void apply(Settings value, Settings current, Settings previous) {
                 RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING,
                 RemoteClusterStateService.INDEX_METADATA_UPLOAD_TIMEOUT_SETTING,
                 RemoteClusterStateService.GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING,
+                RemoteClusterStateService.METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING,
                 RemoteStoreNodeService.REMOTE_STORE_COMPATIBILITY_MODE_SETTING,
                 IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING,
                 IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING,
                 AdmissionControlSettings.ADMISSION_CONTROL_TRANSPORT_LAYER_MODE,
                 CPUBasedAdmissionControllerSettings.CPU_BASED_ADMISSION_CONTROLLER_TRANSPORT_LAYER_MODE,
                 CPUBasedAdmissionControllerSettings.INDEXING_CPU_USAGE_LIMIT,
-                CPUBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT,
-                IndicesService.CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING
+                CPUBasedAdmissionControllerSettings.SEARCH_CPU_USAGE_LIMIT
             )
         )
     );
diff --git a/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java b/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
index b3309b1fd8a63..c892b475d71da 100644
--- a/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
+++ b/server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java
@@ -87,6 +87,8 @@ public class RemoteClusterStateService implements Closeable {
 
     public static final TimeValue GLOBAL_METADATA_UPLOAD_TIMEOUT_DEFAULT = TimeValue.timeValueMillis(20000);
 
+    public static final TimeValue METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT = TimeValue.timeValueMillis(20000);
+
     public static final Setting<TimeValue> INDEX_METADATA_UPLOAD_TIMEOUT_SETTING = Setting.timeSetting(
         "cluster.remote_store.state.index_metadata.upload_timeout",
         INDEX_METADATA_UPLOAD_TIMEOUT_DEFAULT,
@@ -101,6 +103,13 @@ public class RemoteClusterStateService implements Closeable {
         Setting.Property.NodeScope
     );
 
+    public static final Setting<TimeValue> METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING = Setting.timeSetting(
+        "cluster.remote_store.state.metadata_manifest.upload_timeout",
+        METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+
     public static final ChecksumBlobStoreFormat<IndexMetadata> INDEX_METADATA_FORMAT = new ChecksumBlobStoreFormat<>(
         "index-metadata",
         METADATA_NAME_FORMAT,
@@ -157,6 +166,7 @@ public class RemoteClusterStateService implements Closeable {
 
     private volatile TimeValue indexMetadataUploadTimeout;
     private volatile TimeValue globalMetadataUploadTimeout;
+    private volatile TimeValue metadataManifestUploadTimeout;
 
     private final AtomicBoolean deleteStaleMetadataRunning = new AtomicBoolean(false);
     private final RemotePersistenceStats remoteStateStats;
@@ -190,9 +200,11 @@ public RemoteClusterStateService(
         this.slowWriteLoggingThreshold = clusterSettings.get(SLOW_WRITE_LOGGING_THRESHOLD);
         this.indexMetadataUploadTimeout = clusterSettings.get(INDEX_METADATA_UPLOAD_TIMEOUT_SETTING);
         this.globalMetadataUploadTimeout = clusterSettings.get(GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING);
+        this.metadataManifestUploadTimeout = clusterSettings.get(METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING);
         clusterSettings.addSettingsUpdateConsumer(SLOW_WRITE_LOGGING_THRESHOLD, this::setSlowWriteLoggingThreshold);
         clusterSettings.addSettingsUpdateConsumer(INDEX_METADATA_UPLOAD_TIMEOUT_SETTING, this::setIndexMetadataUploadTimeout);
         clusterSettings.addSettingsUpdateConsumer(GLOBAL_METADATA_UPLOAD_TIMEOUT_SETTING, this::setGlobalMetadataUploadTimeout);
+        clusterSettings.addSettingsUpdateConsumer(METADATA_MANIFEST_UPLOAD_TIMEOUT_SETTING, this::setMetadataManifestUploadTimeout);
         this.remoteStateStats = new RemotePersistenceStats();
     }
 
@@ -401,13 +413,13 @@ private String writeGlobalMetadata(ClusterState clusterState) throws IOException
         try {
             if (latch.await(getGlobalMetadataUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
                 // TODO: We should add metrics where transfer is timing out. [Issue: #10687]
-                GlobalMetadataTransferException ex = new GlobalMetadataTransferException(
+                RemoteStateTransferException ex = new RemoteStateTransferException(
                     String.format(Locale.ROOT, "Timed out waiting for transfer of global metadata to complete")
                 );
                 throw ex;
             }
         } catch (InterruptedException ex) {
-            GlobalMetadataTransferException exception = new GlobalMetadataTransferException(
+            RemoteStateTransferException exception = new RemoteStateTransferException(
                 String.format(Locale.ROOT, "Timed out waiting for transfer of global metadata to complete - %s"),
                 ex
             );
@@ -415,7 +427,7 @@ private String writeGlobalMetadata(ClusterState clusterState) throws IOException
             throw exception;
         }
         if (exceptionReference.get() != null) {
-            throw new GlobalMetadataTransferException(exceptionReference.get().getMessage(), exceptionReference.get());
+            throw new RemoteStateTransferException(exceptionReference.get().getMessage(), exceptionReference.get());
         }
         return result.get();
     }
@@ -440,7 +452,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
                 );
                 result.add(uploadedIndexMetadata);
             }, ex -> {
-                assert ex instanceof IndexMetadataTransferException;
+                assert ex instanceof RemoteStateTransferException;
                 logger.error(
                     () -> new ParameterizedMessage("Exception during transfer of IndexMetadata to Remote {}", ex.getMessage()),
                     ex
@@ -457,7 +469,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
 
         try {
             if (latch.await(getIndexMetadataUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
-                IndexMetadataTransferException ex = new IndexMetadataTransferException(
+                RemoteStateTransferException ex = new RemoteStateTransferException(
                     String.format(
                         Locale.ROOT,
                         "Timed out waiting for transfer of index metadata to complete - %s",
@@ -469,7 +481,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
             }
         } catch (InterruptedException ex) {
             exceptionList.forEach(ex::addSuppressed);
-            IndexMetadataTransferException exception = new IndexMetadataTransferException(
+            RemoteStateTransferException exception = new RemoteStateTransferException(
                 String.format(
                     Locale.ROOT,
                     "Timed out waiting for transfer of index metadata to complete - %s",
@@ -481,7 +493,7 @@ private List<UploadedIndexMetadata> writeIndexMetadataParallel(ClusterState clus
             throw exception;
         }
         if (exceptionList.size() > 0) {
-            IndexMetadataTransferException exception = new IndexMetadataTransferException(
+            RemoteStateTransferException exception = new RemoteStateTransferException(
                 String.format(
                     Locale.ROOT,
                     "Exception during transfer of IndexMetadata to Remote %s",
@@ -520,7 +532,7 @@ private void writeIndexMetadataAsync(
                     indexMetadataContainer.path().buildAsString() + indexMetadataFilename
                 )
             ),
-            ex -> latchedActionListener.onFailure(new IndexMetadataTransferException(indexMetadata.getIndex().toString(), ex))
+            ex -> latchedActionListener.onFailure(new RemoteStateTransferException(indexMetadata.getIndex().toString(), ex))
         );
 
         INDEX_METADATA_FORMAT.writeAsyncWithUrgentPriority(
@@ -601,14 +613,45 @@ private ClusterMetadataManifest uploadManifest(
 
     private void writeMetadataManifest(String clusterName, String clusterUUID, ClusterMetadataManifest uploadManifest, String fileName)
         throws IOException {
+        AtomicReference<String> result = new AtomicReference<String>();
+        AtomicReference<Exception> exceptionReference = new AtomicReference<Exception>();
+
         final BlobContainer metadataManifestContainer = manifestContainer(clusterName, clusterUUID);
-        CLUSTER_METADATA_MANIFEST_FORMAT.write(
+
+        // latch to wait until upload is not finished
+        CountDownLatch latch = new CountDownLatch(1);
+
+        LatchedActionListener completionListener = new LatchedActionListener<>(ActionListener.wrap(resp -> {
+            logger.trace(String.format(Locale.ROOT, "Manifest file uploaded successfully."));
+        }, ex -> { exceptionReference.set(ex); }), latch);
+
+        CLUSTER_METADATA_MANIFEST_FORMAT.writeAsyncWithUrgentPriority(
             uploadManifest,
             metadataManifestContainer,
             fileName,
             blobStoreRepository.getCompressor(),
+            completionListener,
             FORMAT_PARAMS
         );
+
+        try {
+            if (latch.await(getMetadataManifestUploadTimeout().millis(), TimeUnit.MILLISECONDS) == false) {
+                RemoteStateTransferException ex = new RemoteStateTransferException(
+                    String.format(Locale.ROOT, "Timed out waiting for transfer of manifest file to complete")
+                );
+                throw ex;
+            }
+        } catch (InterruptedException ex) {
+            RemoteStateTransferException exception = new RemoteStateTransferException(
+                String.format(Locale.ROOT, "Timed out waiting for transfer of manifest file to complete - %s"),
+                ex
+            );
+            Thread.currentThread().interrupt();
+            throw exception;
+        }
+        if (exceptionReference.get() != null) {
+            throw new RemoteStateTransferException(exceptionReference.get().getMessage(), exceptionReference.get());
+        }
         logger.debug(
             "Metadata manifest file [{}] written during [{}] phase. ",
             fileName,
@@ -668,6 +711,10 @@ private void setGlobalMetadataUploadTimeout(TimeValue newGlobalMetadataUploadTim
         this.globalMetadataUploadTimeout = newGlobalMetadataUploadTimeout;
     }
 
+    private void setMetadataManifestUploadTimeout(TimeValue newMetadataManifestUploadTimeout) {
+        this.metadataManifestUploadTimeout = newMetadataManifestUploadTimeout;
+    }
+
     public TimeValue getIndexMetadataUploadTimeout() {
         return this.indexMetadataUploadTimeout;
     }
@@ -676,6 +723,10 @@ public TimeValue getGlobalMetadataUploadTimeout() {
         return this.globalMetadataUploadTimeout;
     }
 
+    public TimeValue getMetadataManifestUploadTimeout() {
+        return this.metadataManifestUploadTimeout;
+    }
+
     static String getManifestFileName(long term, long version, boolean committed) {
         // 123456789012_test-cluster/cluster-state/dsgYj10Nkso7/manifest/manifest__<inverted_term>__<inverted_version>__C/P__<inverted__timestamp>__<codec_version>
         return String.join(
@@ -767,16 +818,16 @@ private IndexMetadata getIndexMetadata(String clusterName, String clusterUUID, U
     }
 
     /**
-     * Fetch latest metadata from remote cluster state including global metadata and index metadata
+     * Fetch latest ClusterState from remote, including global metadata, index metadata and cluster state version
      *
      * @param clusterUUID uuid of cluster state to refer to in remote
      * @param clusterName name of the cluster
      * @return {@link IndexMetadata}
      */
-    public Metadata getLatestMetadata(String clusterName, String clusterUUID) {
+    public ClusterState getLatestClusterState(String clusterName, String clusterUUID) {
         start();
         Optional<ClusterMetadataManifest> clusterMetadataManifest = getLatestClusterMetadataManifest(clusterName, clusterUUID);
-        if (!clusterMetadataManifest.isPresent()) {
+        if (clusterMetadataManifest.isEmpty()) {
             throw new IllegalStateException(
                 String.format(Locale.ROOT, "Latest cluster metadata manifest is not present for the provided clusterUUID: %s", clusterUUID)
             );
@@ -790,7 +841,10 @@ public Metadata getLatestMetadata(String clusterName, String clusterUUID) {
         Map<String, IndexMetadata> indexMetadataMap = new HashMap<>();
         indices.values().forEach(indexMetadata -> { indexMetadataMap.put(indexMetadata.getIndex().getName(), indexMetadata); });
 
-        return Metadata.builder(globalMetadata).indices(indexMetadataMap).build();
+        return ClusterState.builder(ClusterState.EMPTY_STATE)
+            .version(clusterMetadataManifest.get().getStateVersion())
+            .metadata(Metadata.builder(globalMetadata).indices(indexMetadataMap).build())
+            .build();
     }
 
     private Metadata getGlobalMetadata(String clusterName, String clusterUUID, ClusterMetadataManifest clusterMetadataManifest) {
@@ -1085,29 +1139,15 @@ public void writeMetadataFailed() {
     }
 
     /**
-     * Exception for IndexMetadata transfer failures to remote
-     */
-    static class IndexMetadataTransferException extends RuntimeException {
-
-        public IndexMetadataTransferException(String errorDesc) {
-            super(errorDesc);
-        }
-
-        public IndexMetadataTransferException(String errorDesc, Throwable cause) {
-            super(errorDesc, cause);
-        }
-    }
-
-    /**
-     * Exception for GlobalMetadata transfer failures to remote
+     * Exception for Remote state transfer.
      */
-    static class GlobalMetadataTransferException extends RuntimeException {
+    static class RemoteStateTransferException extends RuntimeException {
 
-        public GlobalMetadataTransferException(String errorDesc) {
+        public RemoteStateTransferException(String errorDesc) {
             super(errorDesc);
         }
 
-        public GlobalMetadataTransferException(String errorDesc, Throwable cause) {
+        public RemoteStateTransferException(String errorDesc, Throwable cause) {
             super(errorDesc, cause);
         }
     }
diff --git a/server/src/main/java/org/opensearch/http/HttpTransportSettings.java b/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
index f16f06f414e28..621ef36692178 100644
--- a/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
+++ b/server/src/main/java/org/opensearch/http/HttpTransportSettings.java
@@ -182,6 +182,14 @@ public final class HttpTransportSettings {
         Property.NodeScope
     );
 
+    // A default of 0 means that by default there is no connect timeout
+    public static final Setting<TimeValue> SETTING_HTTP_CONNECT_TIMEOUT = Setting.timeSetting(
+        "http.connect_timeout",
+        new TimeValue(0),
+        new TimeValue(0),
+        Property.NodeScope
+    );
+
     // Tcp socket settings
 
     public static final Setting<Boolean> OLD_SETTING_HTTP_TCP_NO_DELAY = boolSetting(
diff --git a/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java b/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
index b4e90b8ab570a..6fc074fe0de95 100644
--- a/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
+++ b/server/src/main/java/org/opensearch/index/fielddata/IndexNumericFieldData.java
@@ -242,7 +242,7 @@ private XFieldComparatorSource comparatorSource(
                 assert !targetNumericType.isFloatingPoint();
                 source = new IntValuesComparatorSource(this, missingValue, sortMode, nested);
         }
-        if (targetNumericType != getNumericType()) {
+        if (targetNumericType != getNumericType() || getNumericType() == NumericType.HALF_FLOAT) {
             source.disableSkipping(); // disable skipping logic for cast of sort field
         }
         return source;
diff --git a/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
index 4a4b2684b5f4c..b44b4b75549c3 100644
--- a/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/GeoShapeFieldMapper.java
@@ -31,12 +31,15 @@
 
 package org.opensearch.index.mapper;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.document.LatLonShape;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.search.Query;
+import org.opensearch.Version;
 import org.opensearch.common.Explicit;
 import org.opensearch.common.geo.GeometryParser;
 import org.opensearch.common.geo.ShapeRelation;
@@ -77,6 +80,7 @@
  * @opensearch.internal
  */
 public class GeoShapeFieldMapper extends AbstractShapeGeometryFieldMapper<Geometry, Geometry> {
+    private static final Logger logger = LogManager.getLogger(GeoShapeFieldMapper.class);
     public static final String CONTENT_TYPE = "geo_shape";
     public static final FieldType FIELD_TYPE = new FieldType();
     static {
@@ -205,9 +209,24 @@ protected void addDocValuesFields(
         final List<IndexableField> indexableFields,
         final ParseContext context
     ) {
-        Field[] fieldsArray = new Field[indexableFields.size()];
-        fieldsArray = indexableFields.toArray(fieldsArray);
-        context.doc().add(LatLonShape.createDocValueField(name, fieldsArray));
+        /*
+         * We are adding the doc values for GeoShape only if the index is created with 2.9 and above version of
+         * OpenSearch. If we don't do that after the upgrade of OpenSearch customers are not able to index documents
+         * with GeoShape fields. Github issue: https://github.com/opensearch-project/OpenSearch/issues/10958,
+         * https://github.com/opensearch-project/OpenSearch/issues/10795
+         */
+        if (context.indexSettings().getIndexVersionCreated().onOrAfter(Version.V_2_9_0)) {
+            Field[] fieldsArray = new Field[indexableFields.size()];
+            fieldsArray = indexableFields.toArray(fieldsArray);
+            context.doc().add(LatLonShape.createDocValueField(name, fieldsArray));
+        } else {
+            logger.warn(
+                "The index was created with Version : {}, for geoshape doc values to work index must be "
+                    + "created with OpenSearch Version : {} or above",
+                context.indexSettings().getIndexVersionCreated(),
+                Version.V_2_9_0
+            );
+        }
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
index 92ee8067ee4a0..c14b2c92c89c3 100644
--- a/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java
@@ -38,11 +38,24 @@
 import org.apache.lucene.document.FieldType;
 import org.apache.lucene.document.SortedSetDocValuesField;
 import org.apache.lucene.index.IndexOptions;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.FuzzyQuery;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.MultiTermQuery;
+import org.apache.lucene.search.PrefixQuery;
 import org.apache.lucene.search.Query;
+import org.apache.lucene.search.RegexpQuery;
+import org.apache.lucene.search.TermInSetQuery;
+import org.apache.lucene.search.TermRangeQuery;
+import org.apache.lucene.search.WildcardQuery;
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.Operations;
+import org.opensearch.OpenSearchException;
 import org.opensearch.common.Nullable;
+import org.opensearch.common.lucene.BytesRefs;
 import org.opensearch.common.lucene.Lucene;
+import org.opensearch.common.lucene.search.AutomatonQueries;
+import org.opensearch.common.unit.Fuzziness;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.index.analysis.IndexAnalyzers;
 import org.opensearch.index.analysis.NamedAnalyzer;
@@ -62,6 +75,8 @@
 import java.util.Objects;
 import java.util.function.Supplier;
 
+import static org.opensearch.search.SearchService.ALLOW_EXPENSIVE_QUERIES;
+
 /**
  * A field mapper for keywords. This mapper accepts strings and indexes them as-is.
  *
@@ -317,7 +332,7 @@ public IndexFieldData.Builder fielddataBuilder(String fullyQualifiedIndexName, S
         @Override
         public ValueFetcher valueFetcher(QueryShardContext context, SearchLookup searchLookup, String format) {
             if (format != null) {
-                throw new IllegalArgumentException("Field [" + name() + "] of type [" + typeName() + "] doesn't support formats.");
+                throw new IllegalArgumentException("Field [" + name() + "] of type [" + typeName() + "] doesn't " + "support formats.");
             }
 
             return new SourceValueFetcher(name(), context, nullValue) {
@@ -372,17 +387,226 @@ protected BytesRef indexedValueForSearch(Object value) {
             return getTextSearchInfo().getSearchAnalyzer().normalize(name(), value.toString());
         }
 
+        @Override
+        public Query termsQuery(List<?> values, QueryShardContext context) {
+            failIfNotIndexedAndNoDocValues();
+            // has index and doc_values enabled
+            if (isSearchable() && hasDocValues()) {
+                BytesRef[] bytesRefs = new BytesRef[values.size()];
+                for (int i = 0; i < bytesRefs.length; i++) {
+                    bytesRefs[i] = indexedValueForSearch(values.get(i));
+                }
+                Query indexQuery = new TermInSetQuery(name(), bytesRefs);
+                Query dvQuery = new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, name(), bytesRefs);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            // if we only have doc_values enabled, we construct a new query with doc_values re-written
+            if (hasDocValues()) {
+                BytesRef[] bytesRefs = new BytesRef[values.size()];
+                for (int i = 0; i < bytesRefs.length; i++) {
+                    bytesRefs[i] = indexedValueForSearch(values.get(i));
+                }
+                return new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, name(), bytesRefs);
+            }
+            // has index enabled, we're going to return the query as is
+            return super.termsQuery(values, context);
+        }
+
+        @Override
+        public Query prefixQuery(
+            String value,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            boolean caseInsensitive,
+            QueryShardContext context
+        ) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[prefix] queries cannot be executed when '"
+                        + ALLOW_EXPENSIVE_QUERIES.getKey()
+                        + "' is set to false. For optimised prefix queries on text "
+                        + "fields please enable [index_prefixes]."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.prefixQuery(value, method, caseInsensitive, context);
+                Query dvQuery = super.prefixQuery(value, MultiTermQuery.DOC_VALUES_REWRITE, caseInsensitive, context);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                if (caseInsensitive) {
+                    return AutomatonQueries.caseInsensitivePrefixQuery(
+                        (new Term(name(), indexedValueForSearch(value))),
+                        MultiTermQuery.DOC_VALUES_REWRITE
+                    );
+                }
+                return new PrefixQuery(new Term(name(), indexedValueForSearch(value)), MultiTermQuery.DOC_VALUES_REWRITE);
+            }
+            return super.prefixQuery(value, method, caseInsensitive, context);
+        }
+
+        @Override
+        public Query regexpQuery(
+            String value,
+            int syntaxFlags,
+            int matchFlags,
+            int maxDeterminizedStates,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            QueryShardContext context
+        ) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[regexp] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.regexpQuery(value, syntaxFlags, matchFlags, maxDeterminizedStates, method, context);
+                Query dvQuery = super.regexpQuery(
+                    value,
+                    syntaxFlags,
+                    matchFlags,
+                    maxDeterminizedStates,
+                    MultiTermQuery.DOC_VALUES_REWRITE,
+                    context
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new RegexpQuery(
+                    new Term(name(), indexedValueForSearch(value)),
+                    syntaxFlags,
+                    matchFlags,
+                    RegexpQuery.DEFAULT_PROVIDER,
+                    maxDeterminizedStates,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return super.regexpQuery(value, syntaxFlags, matchFlags, maxDeterminizedStates, method, context);
+        }
+
+        @Override
+        public Query rangeQuery(Object lowerTerm, Object upperTerm, boolean includeLower, boolean includeUpper, QueryShardContext context) {
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[range] queries on [text] or [keyword] fields cannot be executed when '"
+                        + ALLOW_EXPENSIVE_QUERIES.getKey()
+                        + "' is set to false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper
+                );
+                Query dvQuery = new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new TermRangeQuery(
+                    name(),
+                    lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                    upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                    includeLower,
+                    includeUpper,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return new TermRangeQuery(
+                name(),
+                lowerTerm == null ? null : indexedValueForSearch(lowerTerm),
+                upperTerm == null ? null : indexedValueForSearch(upperTerm),
+                includeLower,
+                includeUpper
+            );
+        }
+
+        @Override
+        public Query fuzzyQuery(
+            Object value,
+            Fuzziness fuzziness,
+            int prefixLength,
+            int maxExpansions,
+            boolean transpositions,
+            @Nullable MultiTermQuery.RewriteMethod method,
+            QueryShardContext context
+        ) {
+            failIfNotIndexedAndNoDocValues();
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[fuzzy] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+                Query dvQuery = super.fuzzyQuery(
+                    value,
+                    fuzziness,
+                    prefixLength,
+                    maxExpansions,
+                    transpositions,
+                    MultiTermQuery.DOC_VALUES_REWRITE,
+                    context
+                );
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                return new FuzzyQuery(
+                    new Term(name(), indexedValueForSearch(value)),
+                    fuzziness.asDistance(BytesRefs.toString(value)),
+                    prefixLength,
+                    maxExpansions,
+                    transpositions,
+                    MultiTermQuery.DOC_VALUES_REWRITE
+                );
+            }
+            return super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+        }
+
         @Override
         public Query wildcardQuery(
             String value,
             @Nullable MultiTermQuery.RewriteMethod method,
-            boolean caseInsensitve,
+            boolean caseInsensitive,
             QueryShardContext context
         ) {
-            // keyword field types are always normalized, so ignore case sensitivity and force normalize the wildcard
+            if (context.allowExpensiveQueries() == false) {
+                throw new OpenSearchException(
+                    "[wildcard] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to " + "false."
+                );
+            }
+            failIfNotIndexedAndNoDocValues();
+            // keyword field types are always normalized, so ignore case sensitivity and force normalize the
+            // wildcard
             // query text
-            return super.wildcardQuery(value, method, caseInsensitve, true, context);
+            if (isSearchable() && hasDocValues()) {
+                Query indexQuery = super.wildcardQuery(value, method, caseInsensitive, true, context);
+                Query dvQuery = super.wildcardQuery(value, MultiTermQuery.DOC_VALUES_REWRITE, caseInsensitive, true, context);
+                return new IndexOrDocValuesQuery(indexQuery, dvQuery);
+            }
+            if (hasDocValues()) {
+                Term term;
+                value = normalizeWildcardPattern(name(), value, getTextSearchInfo().getSearchAnalyzer());
+                term = new Term(name(), value);
+                if (caseInsensitive) {
+                    return AutomatonQueries.caseInsensitiveWildcardQuery(term, method);
+                }
+                return new WildcardQuery(term, Operations.DEFAULT_DETERMINIZE_WORK_LIMIT, MultiTermQuery.DOC_VALUES_REWRITE);
+            }
+            return super.wildcardQuery(value, method, caseInsensitive, true, context);
         }
+
     }
 
     private final boolean indexed;
@@ -422,8 +646,10 @@ protected KeywordFieldMapper(
         this.indexAnalyzers = builder.indexAnalyzers;
     }
 
-    /** Values that have more chars than the return value of this method will
-     *  be skipped at parsing time. */
+    /**
+     * Values that have more chars than the return value of this method will
+     * be skipped at parsing time.
+     */
     public int ignoreAbove() {
         return ignoreAbove;
     }
diff --git a/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java b/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
index 997835f712038..62acad99074c2 100644
--- a/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
+++ b/server/src/main/java/org/opensearch/index/mapper/MappedFieldType.java
@@ -269,6 +269,21 @@ public Query fuzzyQuery(
         );
     }
 
+    // Fuzzy Query with re-write method
+    public Query fuzzyQuery(
+        Object value,
+        Fuzziness fuzziness,
+        int prefixLength,
+        int maxExpansions,
+        boolean transpositions,
+        @Nullable MultiTermQuery.RewriteMethod method,
+        QueryShardContext context
+    ) {
+        throw new IllegalArgumentException(
+            "Can only use fuzzy queries on keyword and text fields - not on [" + name + "] which is of type [" + typeName() + "]"
+        );
+    }
+
     // Case sensitive form of prefix query
     public final Query prefixQuery(String value, @Nullable MultiTermQuery.RewriteMethod method, QueryShardContext context) {
         return prefixQuery(value, method, false, context);
@@ -433,6 +448,15 @@ protected final void failIfNotIndexed() {
         }
     }
 
+    protected final void failIfNotIndexedAndNoDocValues() {
+        // we fail if a field is both not indexed and does not have doc_values enabled
+        if (isIndexed == false && hasDocValues() == false) {
+            throw new IllegalArgumentException(
+                "Cannot search on field [" + name() + "] since it is both not indexed," + " and does not have doc_values enabled."
+            );
+        }
+    }
+
     public boolean eagerGlobalOrdinals() {
         return eagerGlobalOrdinals;
     }
diff --git a/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java b/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
index aebd7d2ea201a..23bb4cea17a20 100644
--- a/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
+++ b/server/src/main/java/org/opensearch/index/recovery/RemoteStoreRestoreService.java
@@ -138,7 +138,7 @@ public RemoteRestoreResult restore(
         String[] indexNames
     ) {
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap = new HashMap<>();
-        Metadata remoteMetadata = null;
+        ClusterState remoteState = null;
         boolean metadataFromRemoteStore = (restoreClusterUUID == null
             || restoreClusterUUID.isEmpty()
             || restoreClusterUUID.isBlank()) == false;
@@ -150,8 +150,8 @@ public RemoteRestoreResult restore(
                     throw new IllegalArgumentException("clusterUUID to restore from should be different from current cluster UUID");
                 }
                 logger.info("Restoring cluster state from remote store from cluster UUID : [{}]", restoreClusterUUID);
-                remoteMetadata = remoteClusterStateService.getLatestMetadata(currentState.getClusterName().value(), restoreClusterUUID);
-                remoteMetadata.getIndices().values().forEach(indexMetadata -> {
+                remoteState = remoteClusterStateService.getLatestClusterState(currentState.getClusterName().value(), restoreClusterUUID);
+                remoteState.getMetadata().getIndices().values().forEach(indexMetadata -> {
                     indexMetadataMap.put(indexMetadata.getIndex().getName(), new Tuple<>(true, indexMetadata));
                 });
             } catch (Exception e) {
@@ -177,7 +177,7 @@ public RemoteRestoreResult restore(
                 }
             }
         }
-        return executeRestore(currentState, indexMetadataMap, restoreAllShards, remoteMetadata);
+        return executeRestore(currentState, indexMetadataMap, restoreAllShards, remoteState);
     }
 
     /**
@@ -191,7 +191,7 @@ private RemoteRestoreResult executeRestore(
         ClusterState currentState,
         Map<String, Tuple<Boolean, IndexMetadata>> indexMetadataMap,
         boolean restoreAllShards,
-        Metadata remoteMetadata
+        ClusterState remoteState
     ) {
         final String restoreUUID = UUIDs.randomBase64UUID();
         List<String> indicesToBeRestored = new ArrayList<>();
@@ -241,8 +241,11 @@ private RemoteRestoreResult executeRestore(
             totalShards += updatedIndexMetadata.getNumberOfShards();
         }
 
-        if (remoteMetadata != null) {
-            restoreGlobalMetadata(mdBuilder, remoteMetadata);
+        if (remoteState != null) {
+            restoreGlobalMetadata(mdBuilder, remoteState.getMetadata());
+            // Restore ClusterState version
+            logger.info("Restoring ClusterState with Remote State version [{}]", remoteState.version());
+            builder.version(remoteState.version());
         }
 
         RestoreInfo restoreInfo = new RestoreInfo("remote_store", indicesToBeRestored, totalShards, totalShards);
diff --git a/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java b/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
index 94f376d923689..352167597fa81 100644
--- a/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
+++ b/server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java
@@ -71,6 +71,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.OptionalLong;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
@@ -1227,6 +1228,14 @@ public ReplicationCheckpoint getLatestReplicationCheckpoint() {
         return this.latestReplicationCheckpoint;
     }
 
+    private boolean isPrimaryRelocation(String allocationId) {
+        Optional<ShardRouting> shardRouting = routingTable.shards()
+            .stream()
+            .filter(routing -> routing.allocationId().getId().equals(allocationId))
+            .findAny();
+        return shardRouting.isPresent() && shardRouting.get().primary();
+    }
+
     private void createReplicationLagTimers() {
         for (Map.Entry<String, CheckpointState> entry : checkpoints.entrySet()) {
             final String allocationId = entry.getKey();
@@ -1236,6 +1245,7 @@ private void createReplicationLagTimers() {
                 // it is possible for a shard to be in-sync but not yet removed from the checkpoints collection after a failover event.
                 if (cps.inSync
                     && replicationGroup.getUnavailableInSyncShards().contains(allocationId) == false
+                    && isPrimaryRelocation(allocationId) == false
                     && latestReplicationCheckpoint.isAheadOf(cps.visibleReplicationCheckpoint)) {
                     cps.checkpointTimers.computeIfAbsent(latestReplicationCheckpoint, ignored -> new SegmentReplicationLagTimer());
                     logger.trace(
@@ -1267,6 +1277,7 @@ public synchronized void startReplicationLagTimers(ReplicationCheckpoint checkpo
                 final CheckpointState cps = e.getValue();
                 if (cps.inSync
                     && replicationGroup.getUnavailableInSyncShards().contains(allocationId) == false
+                    && isPrimaryRelocation(e.getKey()) == false
                     && latestReplicationCheckpoint.isAheadOf(cps.visibleReplicationCheckpoint)
                     && cps.checkpointTimers.containsKey(latestReplicationCheckpoint)) {
                     cps.checkpointTimers.get(latestReplicationCheckpoint).start();
@@ -1291,6 +1302,7 @@ public synchronized Set<SegmentReplicationShardStats> getSegmentReplicationStats
                     entry -> entry.getKey().equals(this.shardAllocationId) == false
                         && entry.getValue().inSync
                         && replicationGroup.getUnavailableInSyncShards().contains(entry.getKey()) == false
+                        && isPrimaryRelocation(entry.getKey()) == false
                 )
                 .map(entry -> buildShardStats(entry.getKey(), entry.getValue()))
                 .collect(Collectors.toUnmodifiableSet());
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShard.java b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
index 5b6257084e440..cf42c6749fc79 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShard.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
@@ -187,6 +187,7 @@
 import org.opensearch.indices.recovery.RecoveryTarget;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
+import org.opensearch.indices.replication.common.ReplicationTimer;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.Repository;
 import org.opensearch.search.suggest.completion.CompletionStats;
@@ -202,6 +203,7 @@
 import java.nio.file.NoSuchFileException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.HashSet;
@@ -698,7 +700,16 @@ public void updateShardState(
                             if (indexSettings.isSegRepEnabled()) {
                                 // this Shard's engine was read only, we need to update its engine before restoring local history from xlog.
                                 assert newRouting.primary() && currentRouting.primary() == false;
+                                ReplicationTimer timer = new ReplicationTimer();
+                                timer.start();
+                                logger.debug(
+                                    "Resetting engine on promotion of shard [{}] to primary, startTime {}\n",
+                                    shardId,
+                                    timer.startTime()
+                                );
                                 resetEngineToGlobalCheckpoint();
+                                timer.stop();
+                                logger.info("Completed engine failover for shard [{}] in: {} ms", shardId, timer.time());
                                 // It is possible an engine can open with a SegmentInfos on a higher gen but the reader does not refresh to
                                 // trigger our refresh listener.
                                 // Force update the checkpoint post engine reset.
@@ -1996,6 +2007,29 @@ private RemoteSegmentStoreDirectory getRemoteDirectory() {
         return ((RemoteSegmentStoreDirectory) remoteDirectory);
     }
 
+    /**
+    Returns true iff it is able to verify that remote segment store
+    is in sync with local
+     */
+    boolean isRemoteSegmentStoreInSync() {
+        assert indexSettings.isRemoteStoreEnabled();
+        try {
+            RemoteSegmentStoreDirectory directory = getRemoteDirectory();
+            if (directory.readLatestMetadataFile() != null) {
+                // verifying that all files except EXCLUDE_FILES are uploaded to the remote
+                Collection<String> uploadFiles = directory.getSegmentsUploadedToRemoteStore().keySet();
+                SegmentInfos segmentInfos = store.readLastCommittedSegmentsInfo();
+                Collection<String> localFiles = segmentInfos.files(true);
+                if (uploadFiles.containsAll(localFiles)) {
+                    return true;
+                }
+            }
+        } catch (IOException e) {
+            logger.error("Exception while reading latest metadata", e);
+        }
+        return false;
+    }
+
     public void preRecovery() {
         final IndexShardState currentState = this.state; // single volatile read
         if (currentState == IndexShardState.CLOSED) {
@@ -4874,8 +4908,7 @@ public void syncSegmentsFromGivenRemoteSegmentStore(
             remoteStore.incRef();
         }
         Map<String, RemoteSegmentStoreDirectory.UploadedSegmentMetadata> uploadedSegments = sourceRemoteDirectory
-            .initializeToSpecificCommit(primaryTerm, commitGeneration)
-            .getMetadata();
+            .getSegmentsUploadedToRemoteStore();
         final Directory storeDirectory = store.directory();
         store.incRef();
 
diff --git a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
index 464adc88ae16f..dd40327298874 100644
--- a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
@@ -20,6 +20,7 @@
 import org.opensearch.action.LatchedActionListener;
 import org.opensearch.action.bulk.BackoffPolicy;
 import org.opensearch.action.support.GroupedActionListener;
+import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.common.concurrent.GatedCloseable;
 import org.opensearch.common.logging.Loggers;
 import org.opensearch.common.unit.TimeValue;
@@ -179,6 +180,9 @@ private boolean shouldSync(boolean didRefresh, boolean skipPrimaryTermCheck) {
         return this.primaryTerm != indexShard.getOperationPrimaryTerm();
     }
 
+    /*
+     @return false if retry is needed
+     */
     private boolean syncSegments() {
         if (isReadyForUpload() == false) {
             // Following check is required to enable retry and make sure that we do not lose this refresh event
@@ -485,7 +489,9 @@ private void initializeRemoteDirectoryOnTermUpdate() throws IOException {
      * @return true iff primaryMode is true and index shard is not in closed state.
      */
     private boolean isReadyForUpload() {
-        boolean isReady = indexShard.getReplicationTracker().isPrimaryMode() && indexShard.state() != IndexShardState.CLOSED;
+        boolean isReady = (indexShard.getReplicationTracker().isPrimaryMode() && indexShard.state() != IndexShardState.CLOSED)
+            || isLocalOrSnapshotRecovery();
+
         if (isReady == false) {
             StringBuilder sb = new StringBuilder("Skipped syncing segments with");
             if (indexShard.getReplicationTracker() != null) {
@@ -497,11 +503,25 @@ private boolean isReadyForUpload() {
             if (indexShard.getEngineOrNull() != null) {
                 sb.append(" engineType=").append(indexShard.getEngine().getClass().getSimpleName());
             }
+            if (isLocalOrSnapshotRecovery() == false) {
+                sb.append(" recoverySourceType=").append(indexShard.recoveryState().getRecoverySource().getType());
+                sb.append(" primary=").append(indexShard.shardRouting.primary());
+            }
             logger.trace(sb.toString());
         }
         return isReady;
     }
 
+    private boolean isLocalOrSnapshotRecovery() {
+        // In this case when the primary mode is false, we need to upload segments to Remote Store
+        // This is required in case of snapshots/shrink/ split/clone where we need to durable persist
+        // all segments to remote before completing the recovery to ensure durability.
+
+        return (indexShard.state() == IndexShardState.RECOVERING && indexShard.shardRouting.primary())
+            && (indexShard.recoveryState().getRecoverySource().getType() == RecoverySource.Type.LOCAL_SHARDS
+                || indexShard.recoveryState().getRecoverySource().getType() == RecoverySource.Type.SNAPSHOT);
+    }
+
     /**
      * Creates an {@link UploadListener} containing the stats population logic which would be triggered before and after segment upload events
      */
diff --git a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
index c0211e1257c8e..5b1940bb1d9a5 100644
--- a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
+++ b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
@@ -191,6 +191,15 @@ void recoverFromLocalShards(
                     // just trigger a merge to do housekeeping on the
                     // copied segments - we will also see them in stats etc.
                     indexShard.getEngine().forceMerge(false, -1, false, false, false, UUIDs.randomBase64UUID());
+                    if (indexShard.isRemoteTranslogEnabled()) {
+                        if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                            throw new IndexShardRecoveryException(
+                                indexShard.shardId(),
+                                "failed to upload to remote",
+                                new IOException("Failed to upload to remote segment store")
+                            );
+                        }
+                    }
                     return true;
                 } catch (IOException ex) {
                     throw new IndexShardRecoveryException(indexShard.shardId(), "failed to recover from local shards", ex);
@@ -401,6 +410,11 @@ void recoverFromSnapshotAndRemoteStore(
                     indexUUID,
                     shardId
                 );
+                sourceRemoteDirectory.initializeToSpecificCommit(
+                    primaryTerm,
+                    commitGeneration,
+                    recoverySource.snapshot().getSnapshotId().getUUID()
+                );
                 indexShard.syncSegmentsFromGivenRemoteSegmentStore(true, sourceRemoteDirectory, primaryTerm, commitGeneration);
                 final Store store = indexShard.store();
                 if (indexShard.indexSettings.isRemoteTranslogStoreEnabled() == false) {
@@ -418,6 +432,12 @@ void recoverFromSnapshotAndRemoteStore(
                 }
                 indexShard.getEngine().fillSeqNoGaps(indexShard.getPendingPrimaryTerm());
                 indexShard.finalizeRecovery();
+                if (indexShard.isRemoteTranslogEnabled()) {
+                    if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                        listener.onFailure(new IndexShardRestoreFailedException(shardId, "Failed to upload to remote segment store"));
+                        return;
+                    }
+                }
                 indexShard.postRecovery("restore done");
 
                 listener.onResponse(true);
@@ -697,6 +717,12 @@ private void restore(
             }
             indexShard.getEngine().fillSeqNoGaps(indexShard.getPendingPrimaryTerm());
             indexShard.finalizeRecovery();
+            if (indexShard.isRemoteTranslogEnabled()) {
+                if (indexShard.isRemoteSegmentStoreInSync() == false) {
+                    listener.onFailure(new IndexShardRestoreFailedException(shardId, "Failed to upload to remote segment store"));
+                    return;
+                }
+            }
             indexShard.postRecovery("restore done");
             listener.onResponse(true);
         }, e -> listener.onFailure(new IndexShardRestoreFailedException(shardId, "restore failed", e)));
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
index be1f2341236ab..988d52202f975 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
@@ -34,6 +34,7 @@
 import org.opensearch.index.store.lockmanager.FileLockInfo;
 import org.opensearch.index.store.lockmanager.RemoteStoreCommitLevelLockManager;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
+import org.opensearch.index.store.lockmanager.RemoteStoreMetadataLockManager;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadataHandler;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
@@ -160,8 +161,9 @@ public RemoteSegmentMetadata init() throws IOException {
      *
      * @throws IOException if there were any failures in reading the metadata file
      */
-    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration) throws IOException {
-        String metadataFile = getMetadataFileForCommit(primaryTerm, commitGeneration);
+    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration, String acquirerId) throws IOException {
+        String metadataFilePrefix = MetadataFilenameUtils.getMetadataFilePrefixForCommit(primaryTerm, commitGeneration);
+        String metadataFile = ((RemoteStoreMetadataLockManager) mdLockManager).fetchLock(metadataFilePrefix, acquirerId);
         RemoteSegmentMetadata remoteSegmentMetadata = readMetadataFile(metadataFile);
         if (remoteSegmentMetadata != null) {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(remoteSegmentMetadata.getMetadata());
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
index fd7906729e314..756905d02229a 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
@@ -14,10 +14,13 @@
 import org.apache.lucene.store.IndexOutput;
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
 import java.util.Collection;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 /**
  * A Class that implements Remote Store Lock Manager by creating lock files for the remote store files that needs to
@@ -70,6 +73,19 @@ public void release(LockInfo lockInfo) throws IOException {
         }
     }
 
+    public String fetchLock(String filenamePrefix, String acquirerId) throws IOException {
+        Collection<String> lockFiles = lockDirectory.listFilesByPrefix(filenamePrefix);
+        List<String> lockFilesForAcquirer = lockFiles.stream()
+            .filter(lockFile -> acquirerId.equals(FileLockInfo.LockFileUtils.getAcquirerIdFromLock(lockFile)))
+            .map(FileLockInfo.LockFileUtils::getFileToLockNameFromLock)
+            .collect(Collectors.toList());
+        if (lockFilesForAcquirer.size() == 0) {
+            throw new FileNotFoundException("No lock file found for prefix: " + filenamePrefix + " and acquirerId: " + acquirerId);
+        }
+        assert lockFilesForAcquirer.size() == 1;
+        return lockFilesForAcquirer.get(0);
+    }
+
     /**
      * Checks whether a given file have any lock on it or not.
      * @param lockInfo File Lock Info instance for which we need to check if lock is acquired.
diff --git a/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java b/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
index a305a774f5854..65d16e213cad1 100644
--- a/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
+++ b/server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java
@@ -103,6 +103,7 @@ public RemoteFsTranslog(
         try {
             download(translogTransferManager, location, logger);
             Checkpoint checkpoint = readCheckpoint(location);
+            logger.info("Downloaded data from remote translog till maxSeqNo = {}", checkpoint.maxSeqNo);
             this.readers.addAll(recoverFromFiles(checkpoint));
             if (readers.isEmpty()) {
                 String errorMsg = String.format(Locale.ROOT, "%s at least one reader must be recovered", shardId);
@@ -266,9 +267,13 @@ public void rollGeneration() throws IOException {
     }
 
     private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOException {
+        long maxSeqNo = -1;
         try (Releasable ignored = writeLock.acquire()) {
             if (generation == null || generation == current.getGeneration()) {
                 try {
+                    if (closed.get() == false) {
+                        maxSeqNo = getMaxSeqNo();
+                    }
                     final TranslogReader reader = current.closeIntoReader();
                     readers.add(reader);
                     copyCheckpointTo(location.resolve(getCommitCheckpointFileName(current.getGeneration())));
@@ -300,17 +305,17 @@ private boolean prepareAndUpload(Long primaryTerm, Long generation) throws IOExc
             // is not updated in remote translog except in primary to primary recovery.
             if (generation == null) {
                 if (closed.get() == false) {
-                    return upload(primaryTerm, current.getGeneration() - 1);
+                    return upload(primaryTerm, current.getGeneration() - 1, maxSeqNo);
                 } else {
-                    return upload(primaryTerm, current.getGeneration());
+                    return upload(primaryTerm, current.getGeneration(), maxSeqNo);
                 }
             } else {
-                return upload(primaryTerm, generation);
+                return upload(primaryTerm, generation, maxSeqNo);
             }
         }
     }
 
-    private boolean upload(Long primaryTerm, Long generation) throws IOException {
+    private boolean upload(long primaryTerm, long generation, long maxSeqNo) throws IOException {
         // During primary relocation (primary-primary peer recovery), both the old and the new primary have engine
         // created with the RemoteFsTranslog. Both primaries are equipped to upload the translogs. The primary mode check
         // below ensures that the real primary only is uploading. Before the primary mode is set as true for the new
@@ -334,7 +339,7 @@ private boolean upload(Long primaryTerm, Long generation) throws IOException {
         ) {
             return translogTransferManager.transferSnapshot(
                 transferSnapshotProvider,
-                new RemoteFsTranslogTransferListener(generation, primaryTerm)
+                new RemoteFsTranslogTransferListener(generation, primaryTerm, maxSeqNo)
             );
         }
 
@@ -522,23 +527,31 @@ private class RemoteFsTranslogTransferListener implements TranslogTransferListen
         /**
          * Generation for the translog
          */
-        private final Long generation;
+        private final long generation;
 
         /**
          * Primary Term for the translog
          */
-        private final Long primaryTerm;
+        private final long primaryTerm;
+
+        private final long maxSeqNo;
 
-        RemoteFsTranslogTransferListener(Long generation, Long primaryTerm) {
+        RemoteFsTranslogTransferListener(long generation, long primaryTerm, long maxSeqNo) {
             this.generation = generation;
             this.primaryTerm = primaryTerm;
+            this.maxSeqNo = maxSeqNo;
         }
 
         @Override
         public void onUploadComplete(TransferSnapshot transferSnapshot) throws IOException {
             maxRemoteTranslogGenerationUploaded = generation;
             minRemoteGenReferenced = getMinFileGeneration();
-            logger.trace("uploaded translog for {} {} ", primaryTerm, generation);
+            logger.debug(
+                "Successfully uploaded translog for primary term = {}, generation = {}, maxSeqNo = {}",
+                primaryTerm,
+                generation,
+                maxSeqNo
+            );
         }
 
         @Override
diff --git a/server/src/main/java/org/opensearch/indices/IndicesService.java b/server/src/main/java/org/opensearch/indices/IndicesService.java
index 34e0153dbe730..dfa2791e0b532 100644
--- a/server/src/main/java/org/opensearch/indices/IndicesService.java
+++ b/server/src/main/java/org/opensearch/indices/IndicesService.java
@@ -299,17 +299,6 @@ public class IndicesService extends AbstractLifecycleComponent
         Property.Final
     );
 
-    /**
-     * This setting is used to restrict creation of index where the 'index.replication.type' index setting is set.
-     * If disabled, the replication type can be specified.
-     */
-    public static final Setting<Boolean> CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING = Setting.boolSetting(
-        "cluster.restrict.index.replication_type",
-        false,
-        Property.NodeScope,
-        Property.Final
-    );
-
     /**
      * The node's settings.
      */
diff --git a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
index 46095adfe96b4..cb738d74000bc 100644
--- a/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
+++ b/server/src/main/java/org/opensearch/indices/replication/SegmentReplicationTargetService.java
@@ -53,6 +53,7 @@
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicLong;
 
+import static org.opensearch.index.seqno.SequenceNumbers.NO_OPS_PERFORMED;
 import static org.opensearch.indices.replication.SegmentReplicationSourceService.Actions.UPDATE_VISIBLE_CHECKPOINT;
 
 /**
@@ -69,7 +70,7 @@ public class SegmentReplicationTargetService implements IndexEventListener {
 
     private final ReplicationCollection<SegmentReplicationTarget> onGoingReplications;
 
-    private final Map<ShardId, SegmentReplicationTarget> completedReplications = ConcurrentCollections.newConcurrentMap();
+    private final Map<ShardId, SegmentReplicationState> completedReplications = ConcurrentCollections.newConcurrentMap();
 
     private final SegmentReplicationSourceFactory sourceFactory;
 
@@ -191,7 +192,7 @@ public SegmentReplicationState getOngoingEventSegmentReplicationState(ShardId sh
      */
     @Nullable
     public SegmentReplicationState getlatestCompletedEventSegmentReplicationState(ShardId shardId) {
-        return Optional.ofNullable(completedReplications.get(shardId)).map(SegmentReplicationTarget::state).orElse(null);
+        return completedReplications.get(shardId);
     }
 
     /**
@@ -282,6 +283,12 @@ public void onReplicationFailure(
                         }
                     }
                 });
+            } else if (replicaShard.isSegmentReplicationAllowed()) {
+                // if we didn't process the checkpoint because we are up to date,
+                // send our latest checkpoint to the primary to update tracking.
+                // replicationId is not used by the primary set to a default value.
+                final long replicationId = NO_OPS_PERFORMED;
+                updateVisibleCheckpoint(replicationId, replicaShard);
             }
         } else {
             logger.trace(
@@ -518,7 +525,7 @@ public void onResponse(Void o) {
                 logger.debug(() -> new ParameterizedMessage("Finished replicating {} marking as done.", target.description()));
                 onGoingReplications.markAsDone(replicationId);
                 if (target.state().getIndex().recoveredFileCount() != 0 && target.state().getIndex().recoveredBytes() != 0) {
-                    completedReplications.put(target.shardId(), target);
+                    completedReplications.put(target.shardId(), target.state());
                 }
             }
 
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
index 5f81c76b69385..0f3c9872353c1 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/DiversifiedAggregatorFactory.java
@@ -162,6 +162,6 @@ public InternalAggregation buildEmptyAggregation() {
 
     @Override
     protected boolean supportsConcurrentSegmentSearch() {
-        return true;
+        return false;
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
index d3db8a66ee21f..51d9830d3cea0 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/bucket/sampler/SamplerAggregatorFactory.java
@@ -75,6 +75,6 @@ public Aggregator createInternal(
 
     @Override
     protected boolean supportsConcurrentSegmentSearch() {
-        return true;
+        return false;
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
index d0fb0f6da53c4..89c77b3cd403f 100644
--- a/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
+++ b/server/src/main/java/org/opensearch/search/fetch/subphase/highlight/CustomQueryScorer.java
@@ -33,6 +33,7 @@
 package org.opensearch.search.fetch.subphase.highlight;
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.highlight.QueryScorer;
 import org.apache.lucene.search.highlight.WeightedSpanTerm;
@@ -104,6 +105,8 @@ protected void extract(Query query, float boost, Map<String, WeightedSpanTerm> t
                 super.extract(((FunctionScoreQuery) query).getSubQuery(), boost, terms);
             } else if (query instanceof OpenSearchToParentBlockJoinQuery) {
                 super.extract(((OpenSearchToParentBlockJoinQuery) query).getChildQuery(), boost, terms);
+            } else if (query instanceof IndexOrDocValuesQuery) {
+                super.extract(((IndexOrDocValuesQuery) query).getIndexQuery(), boost, terms);
             } else {
                 super.extract(query, boost, terms);
             }
diff --git a/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java b/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
index d4292b85b20a5..8bab961423f91 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/Pipeline.java
@@ -16,11 +16,13 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.search.SearchPhaseResult;
 
+import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -117,92 +119,138 @@ protected void afterResponseProcessor(Processor processor, long timeInNanos) {}
 
     protected void onResponseProcessorFailed(Processor processor) {}
 
-    SearchRequest transformRequest(SearchRequest request) throws SearchPipelineProcessingException {
-        if (searchRequestProcessors.isEmpty() == false) {
-            long pipelineStart = relativeTimeSupplier.getAsLong();
-            beforeTransformRequest();
-            try {
-                try (BytesStreamOutput bytesStreamOutput = new BytesStreamOutput()) {
-                    request.writeTo(bytesStreamOutput);
-                    try (StreamInput in = bytesStreamOutput.bytes().streamInput()) {
-                        try (StreamInput input = new NamedWriteableAwareStreamInput(in, namedWriteableRegistry)) {
-                            request = new SearchRequest(input);
-                        }
-                    }
-                }
-                for (SearchRequestProcessor processor : searchRequestProcessors) {
-                    beforeRequestProcessor(processor);
-                    long start = relativeTimeSupplier.getAsLong();
-                    try {
-                        request = processor.processRequest(request);
-                    } catch (Exception e) {
-                        onRequestProcessorFailed(processor);
-                        if (processor.isIgnoreFailure()) {
-                            logger.warn(
-                                "The exception from request processor ["
-                                    + processor.getType()
-                                    + "] in the search pipeline ["
-                                    + id
-                                    + "] was ignored",
-                                e
-                            );
-                        } else {
-                            throw e;
-                        }
-                    } finally {
-                        long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
-                        afterRequestProcessor(processor, took);
-                    }
+    void transformRequest(SearchRequest request, ActionListener<SearchRequest> requestListener) throws SearchPipelineProcessingException {
+        if (searchRequestProcessors.isEmpty()) {
+            requestListener.onResponse(request);
+            return;
+        }
+
+        try (BytesStreamOutput bytesStreamOutput = new BytesStreamOutput()) {
+            request.writeTo(bytesStreamOutput);
+            try (StreamInput in = bytesStreamOutput.bytes().streamInput()) {
+                try (StreamInput input = new NamedWriteableAwareStreamInput(in, namedWriteableRegistry)) {
+                    request = new SearchRequest(input);
                 }
-            } catch (Exception e) {
-                onTransformRequestFailure();
-                throw new SearchPipelineProcessingException(e);
-            } finally {
-                long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
-                afterTransformRequest(took);
             }
+        } catch (IOException e) {
+            requestListener.onFailure(new SearchPipelineProcessingException(e));
+            return;
         }
-        return request;
+
+        ActionListener<SearchRequest> finalListener = getTerminalSearchRequestActionListener(requestListener);
+
+        // Chain listeners back-to-front
+        ActionListener<SearchRequest> currentListener = finalListener;
+        for (int i = searchRequestProcessors.size() - 1; i >= 0; i--) {
+            final ActionListener<SearchRequest> nextListener = currentListener;
+            SearchRequestProcessor processor = searchRequestProcessors.get(i);
+            currentListener = ActionListener.wrap(r -> {
+                long start = relativeTimeSupplier.getAsLong();
+                beforeRequestProcessor(processor);
+                processor.processRequestAsync(r, ActionListener.wrap(rr -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterRequestProcessor(processor, took);
+                    nextListener.onResponse(rr);
+                }, e -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterRequestProcessor(processor, took);
+                    onRequestProcessorFailed(processor);
+                    if (processor.isIgnoreFailure()) {
+                        logger.warn(
+                            "The exception from request processor ["
+                                + processor.getType()
+                                + "] in the search pipeline ["
+                                + id
+                                + "] was ignored",
+                            e
+                        );
+                        nextListener.onResponse(r);
+                    } else {
+                        nextListener.onFailure(new SearchPipelineProcessingException(e));
+                    }
+                }));
+            }, finalListener::onFailure);
+        }
+
+        beforeTransformRequest();
+        currentListener.onResponse(request);
     }
 
-    SearchResponse transformResponse(SearchRequest request, SearchResponse response) throws SearchPipelineProcessingException {
-        if (searchResponseProcessors.isEmpty() == false) {
-            long pipelineStart = relativeTimeSupplier.getAsLong();
-            beforeTransformResponse();
-            try {
-                for (SearchResponseProcessor processor : searchResponseProcessors) {
-                    beforeResponseProcessor(processor);
-                    long start = relativeTimeSupplier.getAsLong();
-                    try {
-                        response = processor.processResponse(request, response);
-                    } catch (Exception e) {
-                        onResponseProcessorFailed(processor);
-                        if (processor.isIgnoreFailure()) {
-                            logger.warn(
-                                "The exception from response processor ["
-                                    + processor.getType()
-                                    + "] in the search pipeline ["
-                                    + id
-                                    + "] was ignored",
-                                e
-                            );
-                        } else {
-                            throw e;
-                        }
-                    } finally {
-                        long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
-                        afterResponseProcessor(processor, took);
+    private ActionListener<SearchRequest> getTerminalSearchRequestActionListener(ActionListener<SearchRequest> requestListener) {
+        final long pipelineStart = relativeTimeSupplier.getAsLong();
+
+        return ActionListener.wrap(r -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
+            afterTransformRequest(took);
+            requestListener.onResponse(new PipelinedRequest(this, r));
+        }, e -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
+            afterTransformRequest(took);
+            onTransformRequestFailure();
+            requestListener.onFailure(new SearchPipelineProcessingException(e));
+        });
+    }
+
+    ActionListener<SearchResponse> transformResponseListener(SearchRequest request, ActionListener<SearchResponse> responseListener) {
+        if (searchResponseProcessors.isEmpty()) {
+            // No response transformation necessary
+            return responseListener;
+        }
+
+        long[] pipelineStart = new long[1];
+
+        final ActionListener<SearchResponse> originalListener = responseListener;
+        responseListener = ActionListener.wrap(r -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart[0]);
+            afterTransformResponse(took);
+            originalListener.onResponse(r);
+        }, e -> {
+            long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart[0]);
+            afterTransformResponse(took);
+            onTransformResponseFailure();
+            originalListener.onFailure(e);
+        });
+        ActionListener<SearchResponse> finalListener = responseListener; // Jump directly to this one on exception.
+
+        for (int i = searchResponseProcessors.size() - 1; i >= 0; i--) {
+            final ActionListener<SearchResponse> currentFinalListener = responseListener;
+            final SearchResponseProcessor processor = searchResponseProcessors.get(i);
+
+            responseListener = ActionListener.wrap(r -> {
+                beforeResponseProcessor(processor);
+                final long start = relativeTimeSupplier.getAsLong();
+                processor.processResponseAsync(request, r, ActionListener.wrap(rr -> {
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterResponseProcessor(processor, took);
+                    currentFinalListener.onResponse(rr);
+                }, e -> {
+                    onResponseProcessorFailed(processor);
+                    long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - start);
+                    afterResponseProcessor(processor, took);
+                    if (processor.isIgnoreFailure()) {
+                        logger.warn(
+                            "The exception from response processor ["
+                                + processor.getType()
+                                + "] in the search pipeline ["
+                                + id
+                                + "] was ignored",
+                            e
+                        );
+                        // Pass the previous response through to the next processor in the chain
+                        currentFinalListener.onResponse(r);
+                    } else {
+                        currentFinalListener.onFailure(new SearchPipelineProcessingException(e));
                     }
-                }
-            } catch (Exception e) {
-                onTransformResponseFailure();
-                throw new SearchPipelineProcessingException(e);
-            } finally {
-                long took = TimeUnit.NANOSECONDS.toMillis(relativeTimeSupplier.getAsLong() - pipelineStart);
-                afterTransformResponse(took);
-            }
+                }));
+            }, finalListener::onFailure);
         }
-        return response;
+        final ActionListener<SearchResponse> chainListener = responseListener;
+        return ActionListener.wrap(r -> {
+            beforeTransformResponse();
+            pipelineStart[0] = relativeTimeSupplier.getAsLong();
+            chainListener.onResponse(r);
+        }, originalListener::onFailure);
+
     }
 
     <Result extends SearchPhaseResult> void runSearchPhaseResultsTransformer(
diff --git a/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java b/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
index 5a7539808c127..77dfc6bcd4fc5 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/PipelinedRequest.java
@@ -12,6 +12,7 @@
 import org.opensearch.action.search.SearchPhaseResults;
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.search.SearchPhaseResult;
 
 /**
@@ -27,8 +28,12 @@ public final class PipelinedRequest extends SearchRequest {
         this.pipeline = pipeline;
     }
 
-    public SearchResponse transformResponse(SearchResponse response) {
-        return pipeline.transformResponse(this, response);
+    public void transformRequest(ActionListener<SearchRequest> requestListener) {
+        pipeline.transformRequest(this, requestListener);
+    }
+
+    public ActionListener<SearchResponse> transformResponseListener(ActionListener<SearchResponse> responseListener) {
+        return pipeline.transformResponseListener(this, responseListener);
     }
 
     public <Result extends SearchPhaseResult> void transformSearchPhaseResults(
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
index 739101519ff98..580fe1b7c4216 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
@@ -408,8 +408,7 @@ public PipelinedRequest resolvePipeline(SearchRequest searchRequest) {
                 pipeline = pipelineHolder.pipeline;
             }
         }
-        SearchRequest transformedRequest = pipeline.transformRequest(searchRequest);
-        return new PipelinedRequest(pipeline, transformedRequest);
+        return new PipelinedRequest(pipeline, searchRequest);
     }
 
     Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessorFactories() {
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
index c236cde1a5cc0..427c9e4ab694c 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchRequestProcessor.java
@@ -9,10 +9,37 @@
 package org.opensearch.search.pipeline;
 
 import org.opensearch.action.search.SearchRequest;
+import org.opensearch.core.action.ActionListener;
 
 /**
  * Interface for a search pipeline processor that modifies a search request.
  */
 public interface SearchRequestProcessor extends Processor {
+
+    /**
+     * Transform a {@link SearchRequest}. Executed on the coordinator node before any {@link org.opensearch.action.search.SearchPhase}
+     * executes.
+     * <p>
+     * Implement this method if the processor makes no asynchronous calls.
+     * @param request the executed {@link SearchRequest}
+     * @return a new {@link SearchRequest} (or the input {@link SearchRequest} if no changes)
+     * @throws Exception if an error occurs during processing
+     */
     SearchRequest processRequest(SearchRequest request) throws Exception;
+
+    /**
+     * Transform a {@link SearchRequest}. Executed on the coordinator node before any {@link org.opensearch.action.search.SearchPhase}
+     * executes.
+     * <p>
+     * Expert method: Implement this if the processor needs to make asynchronous calls. Otherwise, implement processRequest.
+     * @param request the executed {@link SearchRequest}
+     * @param requestListener callback to be invoked on successful processing or on failure
+     */
+    default void processRequestAsync(SearchRequest request, ActionListener<SearchRequest> requestListener) {
+        try {
+            requestListener.onResponse(processRequest(request));
+        } catch (Exception e) {
+            requestListener.onFailure(e);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java b/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
index 2f22cedb9b5c0..21136ce208fee 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchResponseProcessor.java
@@ -10,10 +10,37 @@
 
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
+import org.opensearch.core.action.ActionListener;
 
 /**
  * Interface for a search pipeline processor that modifies a search response.
  */
 public interface SearchResponseProcessor extends Processor {
+
+    /**
+     * Transform a {@link SearchResponse}, possibly based on the executed {@link SearchRequest}.
+     * <p>
+     * Implement this method if the processor makes no asynchronous calls.
+     * @param request the executed {@link SearchRequest}
+     * @param response the current {@link SearchResponse}, possibly modified by earlier processors
+     * @return a modified {@link SearchResponse} (or the input {@link SearchResponse} if no changes)
+     * @throws Exception if an error occurs during processing
+     */
     SearchResponse processResponse(SearchRequest request, SearchResponse response) throws Exception;
+
+    /**
+     * Transform a {@link SearchResponse}, possibly based on the executed {@link SearchRequest}.
+     * <p>
+     * Expert method: Implement this if the processor needs to make asynchronous calls. Otherwise, implement processResponse.
+     * @param request the executed {@link SearchRequest}
+     * @param response the current {@link SearchResponse}, possibly modified by earlier processors
+     * @param responseListener callback to be invoked on successful processing or on failure
+     */
+    default void processResponseAsync(SearchRequest request, SearchResponse response, ActionListener<SearchResponse> responseListener) {
+        try {
+            responseListener.onResponse(processResponse(request, response));
+        } catch (Exception e) {
+            responseListener.onFailure(e);
+        }
+    }
 }
diff --git a/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java b/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
index 3050d1674a95b..80f4ebf5d737a 100644
--- a/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
+++ b/server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java
@@ -368,6 +368,7 @@ public void testSerialization() throws IOException {
                             .getPersistenceStats()
                             .get(0);
                         PersistedStateStats remoteStateStats = stateStats.getPersistenceStats().get(0);
+                        assertEquals(remoteStateStats.getStatsName(), deserializedRemoteStateStats.getStatsName());
                         assertEquals(remoteStateStats.getFailedCount(), deserializedRemoteStateStats.getFailedCount());
                         assertEquals(remoteStateStats.getSuccessCount(), deserializedRemoteStateStats.getSuccessCount());
                         assertEquals(remoteStateStats.getTotalTimeInMillis(), deserializedRemoteStateStats.getTotalTimeInMillis());
diff --git a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
index cace66d8c6d9e..e40826915c848 100644
--- a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
+++ b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
@@ -139,7 +139,6 @@
 import static org.opensearch.indices.IndicesService.CLUSTER_MINIMUM_INDEX_REFRESH_INTERVAL_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_INDEX_RESTRICT_ASYNC_DURABILITY_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_REPLICATION_TYPE_SETTING;
-import static org.opensearch.indices.IndicesService.CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING;
 import static org.opensearch.indices.ShardLimitValidatorTests.createTestShardLimitService;
 import static org.opensearch.node.Node.NODE_ATTRIBUTES;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY;
@@ -1178,8 +1177,6 @@ public void testvalidateIndexSettings() {
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey() + "zone.values", "a, b")
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey() + "rack.values", "c, d, e")
             .put(AwarenessReplicaBalance.CLUSTER_ROUTING_ALLOCATION_AWARENESS_BALANCE_SETTING.getKey(), true)
-            .put(CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING.getKey(), true)
-            .put(SETTING_REPLICATION_TYPE, randomFrom(ReplicationType.values()))
             .build();
         ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
         when(clusterService.getSettings()).thenReturn(settings);
@@ -1203,12 +1200,8 @@ public void testvalidateIndexSettings() {
         );
 
         List<String> validationErrors = checkerService.getIndexSettingsValidationErrors(settings, false, Optional.empty());
-        assertThat(validationErrors.size(), is(2));
-        assertThat(
-            validationErrors.get(0),
-            is("index setting [index.replication.type] is not allowed to be set as [cluster.restrict.index.replication_type=true]")
-        );
-        assertThat(validationErrors.get(1), is("expected total copies needs to be a multiple of total awareness attributes [3]"));
+        assertThat(validationErrors.size(), is(1));
+        assertThat(validationErrors.get(0), is("expected total copies needs to be a multiple of total awareness attributes [3]"));
 
         settings = Settings.builder()
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.getKey(), "zone, rack")
@@ -1216,13 +1209,8 @@ public void testvalidateIndexSettings() {
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey() + "rack.values", "c, d, e")
             .put(AwarenessReplicaBalance.CLUSTER_ROUTING_ALLOCATION_AWARENESS_BALANCE_SETTING.getKey(), true)
             .put(SETTING_NUMBER_OF_REPLICAS, 2)
-            .put(CLUSTER_RESTRICT_INDEX_REPLICATION_TYPE_SETTING.getKey(), false)
-            .put(SETTING_REPLICATION_TYPE, randomFrom(ReplicationType.values()))
             .build();
 
-        clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
-        when(clusterService.getClusterSettings()).thenReturn(clusterSettings);
-
         validationErrors = checkerService.getIndexSettingsValidationErrors(settings, false, Optional.empty());
         assertThat(validationErrors.size(), is(0));
 
diff --git a/server/src/test/java/org/opensearch/common/RoundingTests.java b/server/src/test/java/org/opensearch/common/RoundingTests.java
index 1a499bac3e2e8..cc71ee08abcca 100644
--- a/server/src/test/java/org/opensearch/common/RoundingTests.java
+++ b/server/src/test/java/org/opensearch/common/RoundingTests.java
@@ -33,7 +33,6 @@
 package org.opensearch.common;
 
 import org.opensearch.common.collect.Tuple;
-import org.opensearch.common.rounding.DateTimeUnit;
 import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.time.DateFormatters;
 import org.opensearch.common.unit.TimeValue;
@@ -236,7 +235,7 @@ public void testOffsetRounding() {
 
     /**
      * Randomized test on TimeUnitRounding. Test uses random
-     * {@link DateTimeUnit} and {@link ZoneId} and often (50% of the time)
+     * {@link org.opensearch.common.Rounding.DateTimeUnit} and {@link ZoneId} and often (50% of the time)
      * chooses test dates that are exactly on or close to offset changes (e.g.
      * DST) in the chosen time zone.
      * <p>
diff --git a/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java b/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java
deleted file mode 100644
index 7b87e136c5f38..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/DateTimeUnitTests.java
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.test.OpenSearchTestCase;
-
-import static org.opensearch.common.rounding.DateTimeUnit.DAY_OF_MONTH;
-import static org.opensearch.common.rounding.DateTimeUnit.HOUR_OF_DAY;
-import static org.opensearch.common.rounding.DateTimeUnit.MINUTES_OF_HOUR;
-import static org.opensearch.common.rounding.DateTimeUnit.MONTH_OF_YEAR;
-import static org.opensearch.common.rounding.DateTimeUnit.QUARTER;
-import static org.opensearch.common.rounding.DateTimeUnit.SECOND_OF_MINUTE;
-import static org.opensearch.common.rounding.DateTimeUnit.WEEK_OF_WEEKYEAR;
-import static org.opensearch.common.rounding.DateTimeUnit.YEAR_OF_CENTURY;
-
-public class DateTimeUnitTests extends OpenSearchTestCase {
-
-    /**
-     * test that we don't accidentally change enum ids
-     */
-    public void testEnumIds() {
-        assertEquals(1, WEEK_OF_WEEKYEAR.id());
-        assertEquals(WEEK_OF_WEEKYEAR, DateTimeUnit.resolve((byte) 1));
-
-        assertEquals(2, YEAR_OF_CENTURY.id());
-        assertEquals(YEAR_OF_CENTURY, DateTimeUnit.resolve((byte) 2));
-
-        assertEquals(3, QUARTER.id());
-        assertEquals(QUARTER, DateTimeUnit.resolve((byte) 3));
-
-        assertEquals(4, MONTH_OF_YEAR.id());
-        assertEquals(MONTH_OF_YEAR, DateTimeUnit.resolve((byte) 4));
-
-        assertEquals(5, DAY_OF_MONTH.id());
-        assertEquals(DAY_OF_MONTH, DateTimeUnit.resolve((byte) 5));
-
-        assertEquals(6, HOUR_OF_DAY.id());
-        assertEquals(HOUR_OF_DAY, DateTimeUnit.resolve((byte) 6));
-
-        assertEquals(7, MINUTES_OF_HOUR.id());
-        assertEquals(MINUTES_OF_HOUR, DateTimeUnit.resolve((byte) 7));
-
-        assertEquals(8, SECOND_OF_MINUTE.id());
-        assertEquals(SECOND_OF_MINUTE, DateTimeUnit.resolve((byte) 8));
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java b/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java
deleted file mode 100644
index 3088067cd1f84..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/RoundingDuelTests.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.test.OpenSearchTestCase;
-import org.joda.time.DateTimeZone;
-
-import java.time.ZoneOffset;
-
-import static org.hamcrest.Matchers.is;
-
-public class RoundingDuelTests extends OpenSearchTestCase {
-
-    // dont include nano/micro seconds as rounding would become zero then and throw an exception
-    private static final String[] ALLOWED_TIME_SUFFIXES = new String[] { "d", "h", "ms", "s", "m" };
-
-    public void testDuellingImplementations() {
-        org.opensearch.common.Rounding.DateTimeUnit randomDateTimeUnit = randomFrom(org.opensearch.common.Rounding.DateTimeUnit.values());
-        org.opensearch.common.Rounding.Prepared rounding;
-        Rounding roundingJoda;
-
-        if (randomBoolean()) {
-            rounding = org.opensearch.common.Rounding.builder(randomDateTimeUnit).timeZone(ZoneOffset.UTC).build().prepareForUnknown();
-            DateTimeUnit dateTimeUnit = DateTimeUnit.resolve(randomDateTimeUnit.getId());
-            roundingJoda = Rounding.builder(dateTimeUnit).timeZone(DateTimeZone.UTC).build();
-        } else {
-            TimeValue interval = timeValue();
-            rounding = org.opensearch.common.Rounding.builder(interval).timeZone(ZoneOffset.UTC).build().prepareForUnknown();
-            roundingJoda = Rounding.builder(interval).timeZone(DateTimeZone.UTC).build();
-        }
-
-        long roundValue = randomLong();
-        assertThat(roundingJoda.round(roundValue), is(rounding.round(roundValue)));
-    }
-
-    static TimeValue timeValue() {
-        return TimeValue.parseTimeValue(randomIntBetween(1, 1000) + randomFrom(ALLOWED_TIME_SUFFIXES), "settingName");
-    }
-}
diff --git a/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java b/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java
deleted file mode 100644
index d1b3adcd55f0c..0000000000000
--- a/server/src/test/java/org/opensearch/common/rounding/TimeZoneRoundingTests.java
+++ /dev/null
@@ -1,822 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
-package org.opensearch.common.rounding;
-
-import org.opensearch.common.collect.Tuple;
-import org.opensearch.common.rounding.Rounding.TimeIntervalRounding;
-import org.opensearch.common.rounding.Rounding.TimeUnitRounding;
-import org.opensearch.common.unit.TimeValue;
-import org.opensearch.test.OpenSearchTestCase;
-import org.joda.time.DateTime;
-import org.joda.time.DateTimeConstants;
-import org.joda.time.DateTimeZone;
-import org.joda.time.format.DateTimeFormat;
-import org.joda.time.format.DateTimeFormatter;
-import org.joda.time.format.ISODateTimeFormat;
-import org.hamcrest.Description;
-import org.hamcrest.Matcher;
-import org.hamcrest.TypeSafeMatcher;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.greaterThan;
-import static org.hamcrest.Matchers.greaterThanOrEqualTo;
-import static org.hamcrest.Matchers.lessThan;
-import static org.hamcrest.Matchers.lessThanOrEqualTo;
-import static org.hamcrest.Matchers.startsWith;
-
-public class TimeZoneRoundingTests extends OpenSearchTestCase {
-
-    public void testUTCTimeUnitRounding() {
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).build();
-        DateTimeZone tz = DateTimeZone.UTC;
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-01T00:00:00.000Z")), isDate(time("2009-03-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.WEEK_OF_WEEKYEAR).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-09T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-16T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.QUARTER).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-04-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T01:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-10T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-01T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2013-01-01T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.MINUTES_OF_HOUR).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:01:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T00:01:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.SECOND_OF_MINUTE).build();
-        assertThat(tzRounding.round(time("2012-01-10T01:01:01")), isDate(time("2012-01-10T01:01:01.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2012-01-09T00:00:00.000Z")), isDate(time("2012-01-09T00:00:01.000Z"), tz));
-    }
-
-    public void testUTCIntervalRounding() {
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(12)).build();
-        DateTimeZone tz = DateTimeZone.UTC;
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T00:00:00.000Z")), isDate(time("2009-02-03T12:00:00.000Z"), tz));
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T12:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T12:00:00.000Z")), isDate(time("2009-02-04T00:00:00.000Z"), tz));
-
-        tzRounding = Rounding.builder(TimeValue.timeValueHours(48)).build();
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T00:00:00.000Z")), isDate(time("2009-02-05T00:00:00.000Z"), tz));
-        assertThat(tzRounding.round(time("2009-02-05T13:01:01")), isDate(time("2009-02-05T00:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-05T00:00:00.000Z")), isDate(time("2009-02-07T00:00:00.000Z"), tz));
-    }
-
-    /**
-     * test TimeIntervalRounding, (interval &lt; 12h) with time zone shift
-     */
-    public void testTimeIntervalRounding() {
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-1);
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(6)).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T00:01:01")), isDate(time("2009-02-02T19:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T19:00:00.000Z")), isDate(time("2009-02-03T01:00:00.000Z"), tz));
-
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T13:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T13:00:00.000Z")), isDate(time("2009-02-03T19:00:00.000Z"), tz));
-    }
-
-    /**
-     * test DayIntervalRounding, (interval &gt;= 12h) with time zone shift
-     */
-    public void testDayIntervalRounding() {
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-8);
-        Rounding tzRounding = Rounding.builder(TimeValue.timeValueHours(12)).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T00:01:01")), isDate(time("2009-02-02T20:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T20:00:00.000Z")), isDate(time("2009-02-03T08:00:00.000Z"), tz));
-
-        assertThat(tzRounding.round(time("2009-02-03T13:01:01")), isDate(time("2009-02-03T08:00:00.000Z"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T08:00:00.000Z")), isDate(time("2009-02-03T20:00:00.000Z"), tz));
-    }
-
-    public void testDayRounding() {
-        int timezoneOffset = -2;
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(DateTimeZone.forOffsetHours(timezoneOffset)).build();
-        assertThat(tzRounding.round(0), equalTo(0L - TimeValue.timeValueHours(24 + timezoneOffset).millis()));
-        assertThat(
-            tzRounding.nextRoundingValue(0L - TimeValue.timeValueHours(24 + timezoneOffset).millis()),
-            equalTo(TimeValue.timeValueHours(-timezoneOffset).millis())
-        );
-
-        DateTimeZone tz = DateTimeZone.forID("-08:00");
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2012-04-01T04:15:30Z")), isDate(time("2012-03-31T08:00:00Z"), tz));
-
-        tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2012-04-01T04:15:30Z")), equalTo(time("2012-03-01T08:00:00Z")));
-
-        // date in Feb-3rd, but still in Feb-2nd in -02:00 timezone
-        tz = DateTimeZone.forID("-02:00");
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-02T02:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-02T02:00:00")), isDate(time("2009-02-03T02:00:00"), tz));
-
-        // date in Feb-3rd, also in -02:00 timezone
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2009-02-03T02:01:01")), isDate(time("2009-02-03T02:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T02:00:00")), isDate(time("2009-02-04T02:00:00"), tz));
-    }
-
-    public void testTimeRounding() {
-        // hour unit
-        DateTimeZone tz = DateTimeZone.forOffsetHours(-2);
-        Rounding tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(tz).build();
-        assertThat(tzRounding.round(0), equalTo(0L));
-        assertThat(tzRounding.nextRoundingValue(0L), equalTo(TimeValue.timeValueHours(1L).getMillis()));
-
-        assertThat(tzRounding.round(time("2009-02-03T01:01:01")), isDate(time("2009-02-03T01:00:00"), tz));
-        assertThat(tzRounding.nextRoundingValue(time("2009-02-03T01:00:00")), isDate(time("2009-02-03T02:00:00"), tz));
-    }
-
-    public void testTimeUnitRoundingDST() {
-        Rounding tzRounding;
-        // testing savings to non savings switch
-        DateTimeZone cet = DateTimeZone.forID("CET");
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(cet).build();
-        assertThat(tzRounding.round(time("2014-10-26T01:01:01", cet)), isDate(time("2014-10-26T01:00:00+02:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-10-26T01:00:00", cet)), isDate(time("2014-10-26T02:00:00+02:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-10-26T02:00:00", cet)), isDate(time("2014-10-26T02:00:00+01:00"), cet));
-
-        // testing non savings to savings switch
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(cet).build();
-        assertThat(tzRounding.round(time("2014-03-30T01:01:01", cet)), isDate(time("2014-03-30T01:00:00+01:00"), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-03-30T01:00:00", cet)), isDate(time("2014-03-30T03:00:00", cet), cet));
-        assertThat(tzRounding.nextRoundingValue(time("2014-03-30T03:00:00", cet)), isDate(time("2014-03-30T04:00:00", cet), cet));
-
-        // testing non savings to savings switch (America/Chicago)
-        DateTimeZone chg = DateTimeZone.forID("America/Chicago");
-        Rounding tzRounding_utc = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(DateTimeZone.UTC).build();
-        assertThat(tzRounding.round(time("2014-03-09T03:01:01", chg)), isDate(time("2014-03-09T03:00:00", chg), chg));
-
-        Rounding tzRounding_chg = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(chg).build();
-        assertThat(tzRounding_chg.round(time("2014-03-09T03:01:01", chg)), isDate(time("2014-03-09T03:00:00", chg), chg));
-
-        // testing savings to non savings switch 2013 (America/Chicago)
-        assertThat(tzRounding_utc.round(time("2013-11-03T06:01:01", chg)), isDate(time("2013-11-03T06:00:00", chg), chg));
-        assertThat(tzRounding_chg.round(time("2013-11-03T06:01:01", chg)), isDate(time("2013-11-03T06:00:00", chg), chg));
-
-        // testing savings to non savings switch 2014 (America/Chicago)
-        assertThat(tzRounding_utc.round(time("2014-11-02T06:01:01", chg)), isDate(time("2014-11-02T06:00:00", chg), chg));
-        assertThat(tzRounding_chg.round(time("2014-11-02T06:01:01", chg)), isDate(time("2014-11-02T06:00:00", chg), chg));
-    }
-
-    /**
-     * Randomized test on TimeUnitRounding. Test uses random
-     * {@link DateTimeUnit} and {@link DateTimeZone} and often (50% of the time)
-     * chooses test dates that are exactly on or close to offset changes (e.g.
-     * DST) in the chosen time zone.
-     * <p>
-     * It rounds the test date down and up and performs various checks on the
-     * rounding unit interval that is defined by this. Assumptions tested are
-     * described in
-     * {@link #assertInterval(long, long, long, Rounding, DateTimeZone)}
-     */
-    public void testRoundingRandom() {
-        for (int i = 0; i < 1000; ++i) {
-            DateTimeUnit timeUnit = randomTimeUnit();
-            DateTimeZone tz = randomDateTimeZone();
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-            long date = Math.abs(randomLong() % (2 * (long) 10e11)); // 1970-01-01T00:00:00Z - 2033-05-18T05:33:20.000+02:00
-            long unitMillis = timeUnit.field(tz).getDurationField().getUnitMillis();
-            if (randomBoolean()) {
-                nastyDate(date, tz, unitMillis);
-            }
-            final long roundedDate = rounding.round(date);
-            final long nextRoundingValue = rounding.nextRoundingValue(roundedDate);
-
-            assertInterval(roundedDate, date, nextRoundingValue, rounding, tz);
-
-            // check correct unit interval width for units smaller than a day, they should be fixed size except for transitions
-            if (unitMillis <= DateTimeConstants.MILLIS_PER_DAY) {
-                // if the interval defined didn't cross timezone offset transition, it should cover unitMillis width
-                if (tz.getOffset(roundedDate - 1) == tz.getOffset(nextRoundingValue + 1)) {
-                    assertThat(
-                        "unit interval width not as expected for [" + timeUnit + "], [" + tz + "] at " + new DateTime(roundedDate),
-                        nextRoundingValue - roundedDate,
-                        equalTo(unitMillis)
-                    );
-                }
-            }
-        }
-    }
-
-    /**
-     * To be even more nasty, go to a transition in the selected time zone.
-     * In one third of the cases stay there, otherwise go half a unit back or forth
-     */
-    private static long nastyDate(long initialDate, DateTimeZone timezone, long unitMillis) {
-        long date = timezone.nextTransition(initialDate);
-        if (randomBoolean()) {
-            return date + (randomLong() % unitMillis);  // positive and negative offset possible
-        } else {
-            return date;
-        }
-    }
-
-    /**
-     * test DST end with interval rounding
-     * CET: 25 October 2015, 03:00:00 clocks were turned backward 1 hour to 25 October 2015, 02:00:00 local standard time
-     */
-    public void testTimeIntervalCET_DST_End() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2015-10-25T01:55:00+02:00")), isDate(time("2015-10-25T01:40:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:15:00+02:00")), isDate(time("2015-10-25T02:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:35:00+02:00")), isDate(time("2015-10-25T02:20:00+02:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:55:00+02:00")), isDate(time("2015-10-25T02:40:00+02:00"), tz));
-        // after DST shift
-        assertThat(rounding.round(time("2015-10-25T02:15:00+01:00")), isDate(time("2015-10-25T02:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:35:00+01:00")), isDate(time("2015-10-25T02:20:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T02:55:00+01:00")), isDate(time("2015-10-25T02:40:00+01:00"), tz));
-        assertThat(rounding.round(time("2015-10-25T03:15:00+01:00")), isDate(time("2015-10-25T03:00:00+01:00"), tz));
-    }
-
-    /**
-     * test DST start with interval rounding
-     * CET: 27 March 2016, 02:00:00 clocks were turned forward 1 hour to 27 March 2016, 03:00:00 local daylight time
-     */
-    public void testTimeIntervalCET_DST_Start() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-        // test DST start
-        assertThat(rounding.round(time("2016-03-27T01:55:00+01:00")), isDate(time("2016-03-27T01:40:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T02:00:00+01:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:15:00+02:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:35:00+02:00")), isDate(time("2016-03-27T03:20:00+02:00"), tz));
-    }
-
-    /**
-     * test DST start with offset not fitting interval, e.g. Asia/Kathmandu
-     * adding 15min on 1986-01-01T00:00:00 the interval from
-     * 1986-01-01T00:15:00+05:45 to 1986-01-01T00:20:00+05:45 to only be 5min
-     * long
-     */
-    public void testTimeInterval_Kathmandu_DST_Start() {
-        long interval = TimeUnit.MINUTES.toMillis(20);
-        DateTimeZone tz = DateTimeZone.forID("Asia/Kathmandu");
-        Rounding rounding = new TimeIntervalRounding(interval, tz);
-        assertThat(rounding.round(time("1985-12-31T23:55:00+05:30")), isDate(time("1985-12-31T23:40:00+05:30"), tz));
-        assertThat(rounding.round(time("1986-01-01T00:16:00+05:45")), isDate(time("1986-01-01T00:15:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:15:00+05:45") - time("1985-12-31T23:40:00+05:30"), equalTo(TimeUnit.MINUTES.toMillis(20)));
-        assertThat(rounding.round(time("1986-01-01T00:26:00+05:45")), isDate(time("1986-01-01T00:20:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:20:00+05:45") - time("1986-01-01T00:15:00+05:45"), equalTo(TimeUnit.MINUTES.toMillis(5)));
-        assertThat(rounding.round(time("1986-01-01T00:46:00+05:45")), isDate(time("1986-01-01T00:40:00+05:45"), tz));
-        assertThat(time("1986-01-01T00:40:00+05:45") - time("1986-01-01T00:20:00+05:45"), equalTo(TimeUnit.MINUTES.toMillis(20)));
-    }
-
-    /**
-     * Special test for intervals that don't fit evenly into rounding interval.
-     * In this case, when interval crosses DST transition point, rounding in local
-     * time can land in a DST gap which results in wrong UTC rounding values.
-     */
-    public void testIntervalRounding_NotDivisibleInteval() {
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        long interval = TimeUnit.MINUTES.toMillis(14);
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2016-03-27T01:41:00+01:00")), isDate(time("2016-03-27T01:30:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:51:00+01:00")), isDate(time("2016-03-27T01:44:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:59:00+01:00")), isDate(time("2016-03-27T01:58:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:05:00+02:00")), isDate(time("2016-03-27T03:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:12:00+02:00")), isDate(time("2016-03-27T03:08:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:25:00+02:00")), isDate(time("2016-03-27T03:22:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T03:39:00+02:00")), isDate(time("2016-03-27T03:36:00+02:00"), tz));
-    }
-
-    /**
-     * Test for half day rounding intervals scrossing DST.
-     */
-    public void testIntervalRounding_HalfDay_DST() {
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        long interval = TimeUnit.HOURS.toMillis(12);
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-
-        assertThat(rounding.round(time("2016-03-26T01:00:00+01:00")), isDate(time("2016-03-26T00:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-26T13:00:00+01:00")), isDate(time("2016-03-26T12:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T01:00:00+01:00")), isDate(time("2016-03-27T00:00:00+01:00"), tz));
-        assertThat(rounding.round(time("2016-03-27T13:00:00+02:00")), isDate(time("2016-03-27T12:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-28T01:00:00+02:00")), isDate(time("2016-03-28T00:00:00+02:00"), tz));
-        assertThat(rounding.round(time("2016-03-28T13:00:00+02:00")), isDate(time("2016-03-28T12:00:00+02:00"), tz));
-    }
-
-    /**
-     * randomized test on {@link TimeIntervalRounding} with random interval and time zone offsets
-     */
-    public void testIntervalRoundingRandom() {
-        for (int i = 0; i < 1000; i++) {
-            TimeUnit unit = randomFrom(new TimeUnit[] { TimeUnit.MINUTES, TimeUnit.HOURS, TimeUnit.DAYS });
-            long interval = unit.toMillis(randomIntBetween(1, 365));
-            DateTimeZone tz = randomDateTimeZone();
-            Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-            long mainDate = Math.abs(randomLong() % (2 * (long) 10e11)); // 1970-01-01T00:00:00Z - 2033-05-18T05:33:20.000+02:00
-            if (randomBoolean()) {
-                mainDate = nastyDate(mainDate, tz, interval);
-            }
-            // check two intervals around date
-            long previousRoundedValue = Long.MIN_VALUE;
-            for (long date = mainDate - 2 * interval; date < mainDate + 2 * interval; date += interval / 2) {
-                try {
-                    final long roundedDate = rounding.round(date);
-                    final long nextRoundingValue = rounding.nextRoundingValue(roundedDate);
-                    assertThat("Rounding should be idempotent", roundedDate, equalTo(rounding.round(roundedDate)));
-                    assertThat("Rounded value smaller or equal than unrounded", roundedDate, lessThanOrEqualTo(date));
-                    assertThat(
-                        "Values smaller than rounded value should round further down",
-                        rounding.round(roundedDate - 1),
-                        lessThan(roundedDate)
-                    );
-                    assertThat("Rounding should be >= previous rounding value", roundedDate, greaterThanOrEqualTo(previousRoundedValue));
-
-                    if (tz.isFixed()) {
-                        assertThat("NextRounding value should be greater than date", nextRoundingValue, greaterThan(roundedDate));
-                        assertThat(
-                            "NextRounding value should be interval from rounded value",
-                            nextRoundingValue - roundedDate,
-                            equalTo(interval)
-                        );
-                        assertThat(
-                            "NextRounding value should be a rounded date",
-                            nextRoundingValue,
-                            equalTo(rounding.round(nextRoundingValue))
-                        );
-                    }
-                    previousRoundedValue = roundedDate;
-                } catch (AssertionError e) {
-                    logger.error("Rounding error at {}, timezone {}, interval: {},", new DateTime(date, tz), tz, interval);
-                    throw e;
-                }
-            }
-        }
-    }
-
-    /**
-     * Test that rounded values are always greater or equal to last rounded value if date is increasing.
-     * The example covers an interval around 2011-10-30T02:10:00+01:00, time zone CET, interval: 2700000ms
-     */
-    public void testIntervalRoundingMonotonic_CET() {
-        long interval = TimeUnit.MINUTES.toMillis(45);
-        DateTimeZone tz = DateTimeZone.forID("CET");
-        Rounding rounding = new Rounding.TimeIntervalRounding(interval, tz);
-        List<Tuple<String, String>> expectedDates = new ArrayList<>();
-        // first date is the date to be rounded, second the expected result
-        expectedDates.add(new Tuple<>("2011-10-30T01:40:00.000+02:00", "2011-10-30T01:30:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:02:30.000+02:00", "2011-10-30T01:30:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:25:00.000+02:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:47:30.000+02:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:10:00.000+01:00", "2011-10-30T02:15:00.000+02:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:32:30.000+01:00", "2011-10-30T02:15:00.000+01:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T02:55:00.000+01:00", "2011-10-30T02:15:00.000+01:00"));
-        expectedDates.add(new Tuple<>("2011-10-30T03:17:30.000+01:00", "2011-10-30T03:00:00.000+01:00"));
-
-        long previousDate = Long.MIN_VALUE;
-        for (Tuple<String, String> dates : expectedDates) {
-            final long roundedDate = rounding.round(time(dates.v1()));
-            assertThat(roundedDate, isDate(time(dates.v2()), tz));
-            assertThat(roundedDate, greaterThanOrEqualTo(previousDate));
-            previousDate = roundedDate;
-        }
-        // here's what this means for interval widths
-        assertEquals(TimeUnit.MINUTES.toMillis(45), time("2011-10-30T02:15:00.000+02:00") - time("2011-10-30T01:30:00.000+02:00"));
-        assertEquals(TimeUnit.MINUTES.toMillis(60), time("2011-10-30T02:15:00.000+01:00") - time("2011-10-30T02:15:00.000+02:00"));
-        assertEquals(TimeUnit.MINUTES.toMillis(45), time("2011-10-30T03:00:00.000+01:00") - time("2011-10-30T02:15:00.000+01:00"));
-    }
-
-    /**
-     * special test for DST switch from #9491
-     */
-    public void testAmbiguousHoursAfterDSTSwitch() {
-        Rounding tzRounding;
-        final DateTimeZone tz = DateTimeZone.forID("Asia/Jerusalem");
-        tzRounding = Rounding.builder(DateTimeUnit.HOUR_OF_DAY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-10-26T00:30:00+03:00")), isDate(time("2014-10-26T00:00:00+03:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T01:30:00+03:00")), isDate(time("2014-10-26T01:00:00+03:00"), tz));
-        // the utc date for "2014-10-25T03:00:00+03:00" and "2014-10-25T03:00:00+02:00" is the same, local time turns back 1h here
-        assertThat(time("2014-10-26T03:00:00+03:00"), isDate(time("2014-10-26T02:00:00+02:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T01:30:00+02:00")), isDate(time("2014-10-26T01:00:00+02:00"), tz));
-        assertThat(tzRounding.round(time("2014-10-26T02:30:00+02:00")), isDate(time("2014-10-26T02:00:00+02:00"), tz));
-
-        // Day interval
-        tzRounding = Rounding.builder(DateTimeUnit.DAY_OF_MONTH).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-11-11T00:00:00", tz), tz));
-        // DST on
-        assertThat(tzRounding.round(time("2014-08-11T17:00:00", tz)), isDate(time("2014-08-11T00:00:00", tz), tz));
-        // Day of switching DST on -> off
-        assertThat(tzRounding.round(time("2014-10-26T17:00:00", tz)), isDate(time("2014-10-26T00:00:00", tz), tz));
-        // Day of switching DST off -> on
-        assertThat(tzRounding.round(time("2015-03-27T17:00:00", tz)), isDate(time("2015-03-27T00:00:00", tz), tz));
-
-        // Month interval
-        tzRounding = Rounding.builder(DateTimeUnit.MONTH_OF_YEAR).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-11-01T00:00:00", tz), tz));
-        // DST on
-        assertThat(tzRounding.round(time("2014-10-10T17:00:00", tz)), isDate(time("2014-10-01T00:00:00", tz), tz));
-
-        // Year interval
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(time("2014-01-01T00:00:00", tz), tz));
-
-        // Two timestamps in same year and different timezone offset ("Double buckets" issue - #9491)
-        tzRounding = Rounding.builder(DateTimeUnit.YEAR_OF_CENTURY).timeZone(tz).build();
-        assertThat(tzRounding.round(time("2014-11-11T17:00:00", tz)), isDate(tzRounding.round(time("2014-08-11T17:00:00", tz)), tz));
-    }
-
-    /**
-     * test for #10025, strict local to UTC conversion can cause joda exceptions
-     * on DST start
-     */
-    public void testLenientConversionDST() {
-        DateTimeZone tz = DateTimeZone.forID("America/Sao_Paulo");
-        long start = time("2014-10-18T20:50:00.000", tz);
-        long end = time("2014-10-19T01:00:00.000", tz);
-        Rounding tzRounding = new Rounding.TimeUnitRounding(DateTimeUnit.MINUTES_OF_HOUR, tz);
-        Rounding dayTzRounding = new Rounding.TimeIntervalRounding(60000, tz);
-        for (long time = start; time < end; time = time + 60000) {
-            assertThat(tzRounding.nextRoundingValue(time), greaterThan(time));
-            assertThat(dayTzRounding.nextRoundingValue(time), greaterThan(time));
-        }
-    }
-
-    public void testEdgeCasesTransition() {
-        {
-            // standard +/-1 hour DST transition, CET
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("CET");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            // 29 Mar 2015 - Daylight Saving Time Started
-            // at 02:00:00 clocks were turned forward 1 hour to 03:00:00
-            assertInterval(time("2015-03-29T00:00:00.000+01:00"), time("2015-03-29T01:00:00.000+01:00"), rounding, 60, tz);
-            assertInterval(time("2015-03-29T01:00:00.000+01:00"), time("2015-03-29T03:00:00.000+02:00"), rounding, 60, tz);
-            assertInterval(time("2015-03-29T03:00:00.000+02:00"), time("2015-03-29T04:00:00.000+02:00"), rounding, 60, tz);
-
-            // 25 Oct 2015 - Daylight Saving Time Ended
-            // at 03:00:00 clocks were turned backward 1 hour to 02:00:00
-            assertInterval(time("2015-10-25T01:00:00.000+02:00"), time("2015-10-25T02:00:00.000+02:00"), rounding, 60, tz);
-            assertInterval(time("2015-10-25T02:00:00.000+02:00"), time("2015-10-25T02:00:00.000+01:00"), rounding, 60, tz);
-            assertInterval(time("2015-10-25T02:00:00.000+01:00"), time("2015-10-25T03:00:00.000+01:00"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Asia/Kathmandu"
-            // 1 Jan 1986 - Time Zone Change (IST → NPT), at 00:00:00 clocks were turned forward 00:15 minutes
-            //
-            // hour rounding is stable before 1985-12-31T23:00:00.000 and after 1986-01-01T01:00:00.000+05:45
-            // the interval between is 105 minutes long because the hour after transition starts at 00:15
-            // which is not a round value for hourly rounding
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Asia/Kathmandu");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("1985-12-31T22:00:00.000+05:30"), time("1985-12-31T23:00:00.000+05:30"), rounding, 60, tz);
-            assertInterval(time("1985-12-31T23:00:00.000+05:30"), time("1986-01-01T01:00:00.000+05:45"), rounding, 105, tz);
-            assertInterval(time("1986-01-01T01:00:00.000+05:45"), time("1986-01-01T02:00:00.000+05:45"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Australia/Lord_Howe"
-            // 3 Mar 1991 - Daylight Saving Time Ended
-            // at 02:00:00 clocks were turned backward 0:30 hours to Sunday, 3 March 1991, 01:30:00
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Australia/Lord_Howe");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("1991-03-03T00:00:00.000+11:00"), time("1991-03-03T01:00:00.000+11:00"), rounding, 60, tz);
-            assertInterval(time("1991-03-03T01:00:00.000+11:00"), time("1991-03-03T02:00:00.000+10:30"), rounding, 90, tz);
-            assertInterval(time("1991-03-03T02:00:00.000+10:30"), time("1991-03-03T03:00:00.000+10:30"), rounding, 60, tz);
-
-            // 27 Oct 1991 - Daylight Saving Time Started
-            // at 02:00:00 clocks were turned forward 0:30 hours to 02:30:00
-            assertInterval(time("1991-10-27T00:00:00.000+10:30"), time("1991-10-27T01:00:00.000+10:30"), rounding, 60, tz);
-            // the interval containing the switch time is 90 minutes long
-            assertInterval(time("1991-10-27T01:00:00.000+10:30"), time("1991-10-27T03:00:00.000+11:00"), rounding, 90, tz);
-            assertInterval(time("1991-10-27T03:00:00.000+11:00"), time("1991-10-27T04:00:00.000+11:00"), rounding, 60, tz);
-        }
-
-        {
-            // time zone "Pacific/Chatham"
-            // 5 Apr 2015 - Daylight Saving Time Ended
-            // at 03:45:00 clocks were turned backward 1 hour to 02:45:00
-            DateTimeUnit timeUnit = DateTimeUnit.HOUR_OF_DAY;
-            DateTimeZone tz = DateTimeZone.forID("Pacific/Chatham");
-            Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-            assertInterval(time("2015-04-05T02:00:00.000+13:45"), time("2015-04-05T03:00:00.000+13:45"), rounding, 60, tz);
-            assertInterval(time("2015-04-05T03:00:00.000+13:45"), time("2015-04-05T03:00:00.000+12:45"), rounding, 60, tz);
-            assertInterval(time("2015-04-05T03:00:00.000+12:45"), time("2015-04-05T04:00:00.000+12:45"), rounding, 60, tz);
-
-            // 27 Sep 2015 - Daylight Saving Time Started
-            // at 02:45:00 clocks were turned forward 1 hour to 03:45:00
-
-            assertInterval(time("2015-09-27T01:00:00.000+12:45"), time("2015-09-27T02:00:00.000+12:45"), rounding, 60, tz);
-            assertInterval(time("2015-09-27T02:00:00.000+12:45"), time("2015-09-27T04:00:00.000+13:45"), rounding, 60, tz);
-            assertInterval(time("2015-09-27T04:00:00.000+13:45"), time("2015-09-27T05:00:00.000+13:45"), rounding, 60, tz);
-        }
-    }
-
-    public void testDST_Europe_Rome() {
-        // time zone "Europe/Rome", rounding to days. Rome had two midnights on the day the clocks went back in 1978, and
-        // timeZone.convertLocalToUTC() gives the later of the two because Rome is east of UTC, whereas we want the earlier.
-
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("Europe/Rome");
-        Rounding rounding = new TimeUnitRounding(timeUnit, tz);
-
-        {
-            long timeBeforeFirstMidnight = time("1978-09-30T23:59:00+02:00");
-            long floor = rounding.round(timeBeforeFirstMidnight);
-            assertThat(floor, isDate(time("1978-09-30T00:00:00+02:00"), tz));
-        }
-
-        {
-            long timeBetweenMidnights = time("1978-10-01T00:30:00+02:00");
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("1978-10-01T00:00:00+02:00"), tz));
-        }
-
-        {
-            long timeAfterSecondMidnight = time("1978-10-01T00:30:00+01:00");
-            long floor = rounding.round(timeAfterSecondMidnight);
-            assertThat(floor, isDate(time("1978-10-01T00:00:00+02:00"), tz));
-
-            long prevFloor = rounding.round(floor - 1);
-            assertThat(prevFloor, lessThan(floor));
-            assertThat(prevFloor, isDate(time("1978-09-30T00:00:00+02:00"), tz));
-        }
-    }
-
-    /**
-     * Test for a time zone whose days overlap because the clocks are set back across midnight at the end of DST.
-     */
-    public void testDST_America_St_Johns() {
-        // time zone "America/St_Johns", rounding to days.
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("America/St_Johns");
-        Rounding rounding = new TimeUnitRounding(timeUnit, tz);
-
-        // 29 October 2006 - Daylight Saving Time ended, changing the UTC offset from -02:30 to -03:30.
-        // This happened at 02:31 UTC, 00:01 local time, so the clocks were set back 1 hour to 23:01 on the 28th.
-        // This means that 2006-10-29 has _two_ midnights, one in the -02:30 offset and one in the -03:30 offset.
-        // Only the first of these is considered "rounded". Moreover, the extra time between 23:01 and 23:59
-        // should be considered as part of the 28th even though it comes after midnight on the 29th.
-
-        {
-            // Times before the first midnight should be rounded up to the first midnight.
-            long timeBeforeFirstMidnight = time("2006-10-28T23:30:00.000-02:30");
-            long floor = rounding.round(timeBeforeFirstMidnight);
-            assertThat(floor, isDate(time("2006-10-28T00:00:00.000-02:30"), tz));
-            long ceiling = rounding.nextRoundingValue(timeBeforeFirstMidnight);
-            assertThat(ceiling, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-            assertInterval(floor, timeBeforeFirstMidnight, ceiling, rounding, tz);
-        }
-
-        {
-            // Times between the two midnights which are on the later day should be rounded down to the later day's midnight.
-            long timeBetweenMidnights = time("2006-10-29T00:00:30.000-02:30");
-            // (this is halfway through the last minute before the clocks changed, in which local time was ambiguous)
-
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-
-            long ceiling = rounding.nextRoundingValue(timeBetweenMidnights);
-            assertThat(ceiling, isDate(time("2006-10-30T00:00:00.000-03:30"), tz));
-
-            assertInterval(floor, timeBetweenMidnights, ceiling, rounding, tz);
-        }
-
-        {
-            // Times between the two midnights which are on the earlier day should be rounded down to the earlier day's midnight.
-            long timeBetweenMidnights = time("2006-10-28T23:30:00.000-03:30");
-            // (this is halfway through the hour after the clocks changed, in which local time was ambiguous)
-
-            long floor = rounding.round(timeBetweenMidnights);
-            assertThat(floor, isDate(time("2006-10-28T00:00:00.000-02:30"), tz));
-
-            long ceiling = rounding.nextRoundingValue(timeBetweenMidnights);
-            assertThat(ceiling, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-
-            assertInterval(floor, timeBetweenMidnights, ceiling, rounding, tz);
-        }
-
-        {
-            // Times after the second midnight should be rounded down to the first midnight.
-            long timeAfterSecondMidnight = time("2006-10-29T06:00:00.000-03:30");
-            long floor = rounding.round(timeAfterSecondMidnight);
-            assertThat(floor, isDate(time("2006-10-29T00:00:00.000-02:30"), tz));
-            long ceiling = rounding.nextRoundingValue(timeAfterSecondMidnight);
-            assertThat(ceiling, isDate(time("2006-10-30T00:00:00.000-03:30"), tz));
-            assertInterval(floor, timeAfterSecondMidnight, ceiling, rounding, tz);
-        }
-    }
-
-    /**
-     * tests for dst transition with overlaps and day roundings.
-     */
-    public void testDST_END_Edgecases() {
-        // First case, dst happens at 1am local time, switching back one hour.
-        // We want the overlapping hour to count for the next day, making it a 25h interval
-
-        DateTimeUnit timeUnit = DateTimeUnit.DAY_OF_MONTH;
-        DateTimeZone tz = DateTimeZone.forID("Atlantic/Azores");
-        Rounding rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-        // Sunday, 29 October 2000, 01:00:00 clocks were turned backward 1 hour
-        // to Sunday, 29 October 2000, 00:00:00 local standard time instead
-        // which means there were two midnights that day.
-
-        long midnightBeforeTransition = time("2000-10-29T00:00:00", tz);
-        long midnightOfTransition = time("2000-10-29T00:00:00-01:00");
-        assertEquals(60L * 60L * 1000L, midnightOfTransition - midnightBeforeTransition);
-        long nextMidnight = time("2000-10-30T00:00:00", tz);
-
-        assertInterval(midnightBeforeTransition, nextMidnight, rounding, 25 * 60, tz);
-
-        assertThat(rounding.round(time("2000-10-29T06:00:00-01:00")), isDate(time("2000-10-29T00:00:00Z"), tz));
-
-        // Second case, dst happens at 0am local time, switching back one hour to 23pm local time.
-        // We want the overlapping hour to count for the previous day here
-
-        tz = DateTimeZone.forID("America/Lima");
-        rounding = new Rounding.TimeUnitRounding(timeUnit, tz);
-
-        // Sunday, 1 April 1990, 00:00:00 clocks were turned backward 1 hour to
-        // Saturday, 31 March 1990, 23:00:00 local standard time instead
-
-        midnightBeforeTransition = time("1990-03-31T00:00:00.000-04:00");
-        nextMidnight = time("1990-04-01T00:00:00.000-05:00");
-        assertInterval(midnightBeforeTransition, nextMidnight, rounding, 25 * 60, tz);
-
-        // make sure the next interval is 24h long again
-        long midnightAfterTransition = time("1990-04-01T00:00:00.000-05:00");
-        nextMidnight = time("1990-04-02T00:00:00.000-05:00");
-        assertInterval(midnightAfterTransition, nextMidnight, rounding, 24 * 60, tz);
-    }
-
-    /**
-     * Test that time zones are correctly parsed. There is a bug with
-     * Joda 2.9.4 (see https://github.com/JodaOrg/joda-time/issues/373)
-     */
-    public void testsTimeZoneParsing() {
-        final DateTime expected = new DateTime(2016, 11, 10, 5, 37, 59, randomDateTimeZone());
-
-        // Formatter used to print and parse the sample date.
-        // Printing the date works but parsing it back fails
-        // with Joda 2.9.4
-        DateTimeFormatter formatter = DateTimeFormat.forPattern("YYYY-MM-dd'T'HH:mm:ss " + randomFrom("ZZZ", "[ZZZ]", "'['ZZZ']'"));
-
-        String dateTimeAsString = formatter.print(expected);
-        assertThat(dateTimeAsString, startsWith("2016-11-10T05:37:59 "));
-
-        DateTime parsedDateTime = formatter.parseDateTime(dateTimeAsString);
-        assertThat(parsedDateTime.getZone(), equalTo(expected.getZone()));
-    }
-
-    private static void assertInterval(long rounded, long nextRoundingValue, Rounding rounding, int minutes, DateTimeZone tz) {
-        assertInterval(rounded, dateBetween(rounded, nextRoundingValue), nextRoundingValue, rounding, tz);
-        assertEquals(DateTimeConstants.MILLIS_PER_MINUTE * minutes, nextRoundingValue - rounded);
-    }
-
-    /**
-     * perform a number on assertions and checks on {@link TimeUnitRounding} intervals
-     * @param rounded the expected low end of the rounding interval
-     * @param unrounded a date in the interval to be checked for rounding
-     * @param nextRoundingValue the expected upper end of the rounding interval
-     * @param rounding the rounding instance
-     */
-    private static void assertInterval(long rounded, long unrounded, long nextRoundingValue, Rounding rounding, DateTimeZone tz) {
-        assertThat("rounding should be idempotent ", rounding.round(rounded), isDate(rounded, tz));
-        assertThat("rounded value smaller or equal than unrounded" + rounding, rounded, lessThanOrEqualTo(unrounded));
-        assertThat("values less than rounded should round further down" + rounding, rounding.round(rounded - 1), lessThan(rounded));
-        assertThat("nextRounding value should be a rounded date", rounding.round(nextRoundingValue), isDate(nextRoundingValue, tz));
-        assertThat(
-            "values above nextRounding should round down there",
-            rounding.round(nextRoundingValue + 1),
-            isDate(nextRoundingValue, tz)
-        );
-
-        if (isTimeWithWellDefinedRounding(tz, unrounded)) {
-            assertThat("nextRounding value should be greater than date" + rounding, nextRoundingValue, greaterThan(unrounded));
-
-            long dateBetween = dateBetween(rounded, nextRoundingValue);
-            assertThat(
-                "dateBetween [" + new DateTime(dateBetween, tz) + "] should round down to roundedDate",
-                rounding.round(dateBetween),
-                isDate(rounded, tz)
-            );
-            assertThat(
-                "dateBetween [" + new DateTime(dateBetween, tz) + "] should round up to nextRoundingValue",
-                rounding.nextRoundingValue(dateBetween),
-                isDate(nextRoundingValue, tz)
-            );
-        }
-    }
-
-    private static boolean isTimeWithWellDefinedRounding(DateTimeZone tz, long t) {
-        if (tz.getID().equals("America/St_Johns")
-            || tz.getID().equals("America/Goose_Bay")
-            || tz.getID().equals("America/Moncton")
-            || tz.getID().equals("Canada/Newfoundland")) {
-
-            // Clocks went back at 00:01 between 1987 and 2010, causing overlapping days.
-            // These timezones are otherwise uninteresting, so just skip this period.
-
-            return t <= time("1987-10-01T00:00:00Z") || t >= time("2010-12-01T00:00:00Z");
-        }
-
-        if (tz.getID().equals("Antarctica/Casey")) {
-
-            // Clocks went back 3 hours at 02:00 on 2010-03-05, causing overlapping days.
-
-            return t <= time("2010-03-03T00:00:00Z") || t >= time("2010-03-07T00:00:00Z");
-        }
-
-        return true;
-    }
-
-    private static long dateBetween(long lower, long upper) {
-        long dateBetween = randomLongBetween(lower, upper - 1);
-        assert lower <= dateBetween && dateBetween < upper;
-        return dateBetween;
-    }
-
-    private static DateTimeUnit randomTimeUnit() {
-        byte id = (byte) randomIntBetween(1, 8);
-        return DateTimeUnit.resolve(id);
-    }
-
-    private static long time(String time) {
-        return time(time, DateTimeZone.UTC);
-    }
-
-    private static long time(String time, DateTimeZone zone) {
-        return ISODateTimeFormat.dateOptionalTimeParser().withZone(zone).parseMillis(time);
-    }
-
-    private static Matcher<Long> isDate(final long expected, DateTimeZone tz) {
-        return new TypeSafeMatcher<Long>() {
-            @Override
-            public boolean matchesSafely(final Long item) {
-                return expected == item.longValue();
-            }
-
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(new DateTime(expected, tz) + " [" + expected + "] ");
-            }
-
-            @Override
-            protected void describeMismatchSafely(final Long actual, final Description mismatchDescription) {
-                mismatchDescription.appendText(" was ").appendValue(new DateTime(actual, tz) + " [" + actual + "]");
-            }
-        };
-    }
-}
diff --git a/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java b/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
index 586618bd1ecff..65477051cdb30 100644
--- a/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
+++ b/server/src/test/java/org/opensearch/gateway/remote/RemoteClusterStateServiceTests.java
@@ -68,6 +68,7 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
@@ -230,10 +231,17 @@ public void testWriteFullMetadataInParallelSuccess() throws IOException {
 
         ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
         ArgumentCaptor<WriteContext> writeContextArgumentCaptor = ArgumentCaptor.forClass(WriteContext.class);
-
+        AtomicReference<WriteContext> capturedWriteContext = new AtomicReference<>();
         doAnswer((i) -> {
             actionListenerArgumentCaptor.getValue().onResponse(null);
             return null;
+        }).doAnswer((i) -> {
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            capturedWriteContext.set(writeContextArgumentCaptor.getValue());
+            return null;
+        }).doAnswer((i) -> {
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
         }).when(container).asyncBlobUpload(writeContextArgumentCaptor.capture(), actionListenerArgumentCaptor.capture());
 
         remoteClusterStateService.start();
@@ -262,27 +270,30 @@ public void testWriteFullMetadataInParallelSuccess() throws IOException {
         assertThat(manifest.getStateUUID(), is(expectedManifest.getStateUUID()));
         assertThat(manifest.getPreviousClusterUUID(), is(expectedManifest.getPreviousClusterUUID()));
 
-        assertEquals(actionListenerArgumentCaptor.getAllValues().size(), 2);
-        assertEquals(writeContextArgumentCaptor.getAllValues().size(), 2);
+        assertEquals(actionListenerArgumentCaptor.getAllValues().size(), 3);
+        assertEquals(writeContextArgumentCaptor.getAllValues().size(), 3);
 
-        WriteContext capturedWriteContext = writeContextArgumentCaptor.getValue();
-        byte[] writtenBytes = capturedWriteContext.getStreamProvider(Integer.MAX_VALUE).provideStream(0).getInputStream().readAllBytes();
+        byte[] writtenBytes = capturedWriteContext.get()
+            .getStreamProvider(Integer.MAX_VALUE)
+            .provideStream(0)
+            .getInputStream()
+            .readAllBytes();
         IndexMetadata writtenIndexMetadata = RemoteClusterStateService.INDEX_METADATA_FORMAT.deserialize(
-            capturedWriteContext.getFileName(),
+            capturedWriteContext.get().getFileName(),
             blobStoreRepository.getNamedXContentRegistry(),
             new BytesArray(writtenBytes)
         );
 
-        assertEquals(capturedWriteContext.getWritePriority(), WritePriority.URGENT);
+        assertEquals(capturedWriteContext.get().getWritePriority(), WritePriority.URGENT);
         assertEquals(writtenIndexMetadata.getNumberOfShards(), 1);
         assertEquals(writtenIndexMetadata.getNumberOfReplicas(), 0);
         assertEquals(writtenIndexMetadata.getIndex().getName(), "test-index");
         assertEquals(writtenIndexMetadata.getIndex().getUUID(), "index-uuid");
         long expectedChecksum = RemoteTransferContainer.checksumOfChecksum(new ByteArrayIndexInput("metadata-filename", writtenBytes), 8);
-        if (capturedWriteContext.doRemoteDataIntegrityCheck()) {
-            assertEquals(capturedWriteContext.getExpectedChecksum().longValue(), expectedChecksum);
+        if (capturedWriteContext.get().doRemoteDataIntegrityCheck()) {
+            assertEquals(capturedWriteContext.get().getExpectedChecksum().longValue(), expectedChecksum);
         } else {
-            assertEquals(capturedWriteContext.getExpectedChecksum(), null);
+            assertEquals(capturedWriteContext.get().getExpectedChecksum(), null);
         }
 
     }
@@ -306,11 +317,44 @@ public void run() {
 
         remoteClusterStateService.start();
         assertThrows(
-            RemoteClusterStateService.GlobalMetadataTransferException.class,
+            RemoteClusterStateService.RemoteStateTransferException.class,
             () -> remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10))
         );
     }
 
+    public void testTimeoutWhileWritingManifestFile() throws IOException {
+        // verify update metadata manifest upload timeout
+        int metadataManifestUploadTimeout = 2;
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.metadata_manifest.upload_timeout", metadataManifestUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+
+        final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
+        AsyncMultiStreamBlobContainer container = (AsyncMultiStreamBlobContainer) mockBlobStoreObjects(AsyncMultiStreamBlobContainer.class);
+
+        ArgumentCaptor<ActionListener<Void>> actionListenerArgumentCaptor = ArgumentCaptor.forClass(ActionListener.class);
+
+        doAnswer((i) -> { // For Global Metadata
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
+        }).doAnswer((i) -> { // For Index Metadata
+            actionListenerArgumentCaptor.getValue().onResponse(null);
+            return null;
+        }).doAnswer((i) -> {
+            // For Manifest file perform No Op, so latch in code will timeout
+            return null;
+        }).when(container).asyncBlobUpload(any(WriteContext.class), actionListenerArgumentCaptor.capture());
+
+        remoteClusterStateService.start();
+        try {
+            remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10));
+        } catch (Exception e) {
+            assertTrue(e instanceof RemoteClusterStateService.RemoteStateTransferException);
+            assertTrue(e.getMessage().contains("Timed out waiting for transfer of manifest file to complete"));
+        }
+    }
+
     public void testWriteFullMetadataInParallelFailureForIndexMetadata() throws IOException {
         final ClusterState clusterState = generateClusterStateWithOneIndex().nodes(nodesWithLocalNodeClusterManager()).build();
         AsyncMultiStreamBlobContainer container = (AsyncMultiStreamBlobContainer) mockBlobStoreObjects(AsyncMultiStreamBlobContainer.class);
@@ -327,7 +371,7 @@ public void testWriteFullMetadataInParallelFailureForIndexMetadata() throws IOEx
 
         remoteClusterStateService.start();
         assertThrows(
-            RemoteClusterStateService.IndexMetadataTransferException.class,
+            RemoteClusterStateService.RemoteStateTransferException.class,
             () -> remoteClusterStateService.writeFullMetadata(clusterState, randomAlphaOfLength(10))
         );
         assertEquals(0, remoteClusterStateService.getStats().getSuccessCount());
@@ -665,7 +709,8 @@ public void testReadLatestMetadataManifestSuccessButNoIndexMetadata() throws IOE
 
         remoteClusterStateService.start();
         assertEquals(
-            remoteClusterStateService.getLatestMetadata(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+            remoteClusterStateService.getLatestClusterState(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+                .getMetadata()
                 .getIndices()
                 .size(),
             0
@@ -694,8 +739,10 @@ public void testReadLatestMetadataManifestSuccessButIndexMetadataFetchIOExceptio
         remoteClusterStateService.start();
         Exception e = assertThrows(
             IllegalStateException.class,
-            () -> remoteClusterStateService.getLatestMetadata(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
-                .getIndices()
+            () -> remoteClusterStateService.getLatestClusterState(
+                clusterState.getClusterName().value(),
+                clusterState.metadata().clusterUUID()
+            ).getMetadata().getIndices()
         );
         assertEquals(e.getMessage(), "Error while downloading IndexMetadata - " + uploadedIndexMetadata.getUploadedFilename());
     }
@@ -740,10 +787,11 @@ public void testReadGlobalMetadata() throws IOException {
         final ClusterState clusterState = generateClusterStateWithGlobalMetadata().nodes(nodesWithLocalNodeClusterManager()).build();
         remoteClusterStateService.start();
 
+        long prevClusterStateVersion = 13L;
         final ClusterMetadataManifest expectedManifest = ClusterMetadataManifest.builder()
             .indices(List.of())
             .clusterTerm(1L)
-            .stateVersion(1L)
+            .stateVersion(prevClusterStateVersion)
             .stateUUID("state-uuid")
             .clusterUUID("cluster-uuid")
             .codecVersion(MANIFEST_CURRENT_CODEC_VERSION)
@@ -756,12 +804,20 @@ public void testReadGlobalMetadata() throws IOException {
         Metadata expactedMetadata = Metadata.builder().persistentSettings(Settings.builder().put("readonly", true).build()).build();
         mockBlobContainerForGlobalMetadata(mockBlobStoreObjects(), expectedManifest, expactedMetadata);
 
-        Metadata metadata = remoteClusterStateService.getLatestMetadata(
+        ClusterState newClusterState = remoteClusterStateService.getLatestClusterState(
             clusterState.getClusterName().value(),
             clusterState.metadata().clusterUUID()
         );
 
-        assertTrue(Metadata.isGlobalStateEquals(metadata, expactedMetadata));
+        assertTrue(Metadata.isGlobalStateEquals(newClusterState.getMetadata(), expactedMetadata));
+
+        long newClusterStateVersion = newClusterState.getVersion();
+        assert prevClusterStateVersion == newClusterStateVersion : String.format(
+            Locale.ROOT,
+            "ClusterState version is not restored. previousClusterVersion: [%s] is not equal to current [%s]",
+            prevClusterStateVersion,
+            newClusterStateVersion
+        );
     }
 
     public void testReadGlobalMetadataIOException() throws IOException {
@@ -793,7 +849,10 @@ public void testReadGlobalMetadataIOException() throws IOException {
         remoteClusterStateService.start();
         Exception e = assertThrows(
             IllegalStateException.class,
-            () -> remoteClusterStateService.getLatestMetadata(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID())
+            () -> remoteClusterStateService.getLatestClusterState(
+                clusterState.getClusterName().value(),
+                clusterState.metadata().clusterUUID()
+            )
         );
         assertEquals(e.getMessage(), "Error while downloading Global Metadata - " + globalIndexMetadataName);
     }
@@ -824,16 +883,15 @@ public void testReadLatestIndexMetadataSuccess() throws IOException {
             .nodeId("nodeA")
             .opensearchVersion(VersionUtils.randomOpenSearchVersion(random()))
             .previousClusterUUID("prev-cluster-uuid")
-            .globalMetadataFileName("global-metadata-file")
             .codecVersion(ClusterMetadataManifest.CODEC_V0)
             .build();
 
         mockBlobContainer(mockBlobStoreObjects(), expectedManifest, Map.of(index.getUUID(), indexMetadata));
 
-        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestMetadata(
+        Map<String, IndexMetadata> indexMetadataMap = remoteClusterStateService.getLatestClusterState(
             clusterState.getClusterName().value(),
             clusterState.metadata().clusterUUID()
-        ).getIndices();
+        ).getMetadata().getIndices();
 
         assertEquals(indexMetadataMap.size(), 1);
         assertEquals(indexMetadataMap.get(index.getName()).getIndex().getName(), index.getName());
@@ -1128,6 +1186,22 @@ public void testIndexMetadataUploadWaitTimeSetting() {
         assertEquals(indexMetadataUploadTimeout, remoteClusterStateService.getIndexMetadataUploadTimeout().seconds());
     }
 
+    public void testMetadataManifestUploadWaitTimeSetting() {
+        // verify default value
+        assertEquals(
+            RemoteClusterStateService.METADATA_MANIFEST_UPLOAD_TIMEOUT_DEFAULT,
+            remoteClusterStateService.getMetadataManifestUploadTimeout()
+        );
+
+        // verify update metadata manifest upload timeout
+        int metadataManifestUploadTimeout = randomIntBetween(1, 10);
+        Settings newSettings = Settings.builder()
+            .put("cluster.remote_store.state.metadata_manifest.upload_timeout", metadataManifestUploadTimeout + "s")
+            .build();
+        clusterSettings.applySettings(newSettings);
+        assertEquals(metadataManifestUploadTimeout, remoteClusterStateService.getMetadataManifestUploadTimeout().seconds());
+    }
+
     public void testGlobalMetadataUploadWaitTimeSetting() {
         // verify default value
         assertEquals(
diff --git a/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java b/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
index 305c3a3acbf75..81d8bccb86c60 100644
--- a/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
+++ b/server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java
@@ -40,7 +40,6 @@
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.appender.AbstractAppender;
 import org.apache.logging.log4j.core.filter.RegexFilter;
-import org.apache.lucene.codecs.LiveDocsFormat;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.KeywordField;
 import org.apache.lucene.document.LongPoint;
@@ -3237,22 +3236,10 @@ public void testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpEnabled()
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
-
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-
-                // Fail segment merge with diskfull during merging terms.
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                // Fail segment merge with diskfull during merging terms
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3325,7 +3312,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // IndexWriter can throw either IOException or IllegalStateException depending on whether tragedy is set or not.
             expectThrowsAnyOf(
                 Arrays.asList(IOException.class, IllegalStateException.class),
@@ -3345,20 +3331,10 @@ public void testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpDisabled(
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
 
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3439,7 +3415,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // IndexWriter can throw either IOException or IllegalStateException depending on whether tragedy is set or not.
             expectThrowsAnyOf(
                 Arrays.asList(IOException.class, IllegalStateException.class),
@@ -3459,20 +3434,10 @@ public void testUnreferencedFileCleanUpFailsOnSegmentMergeFailureWhenDirectoryCl
         MockDirectoryWrapper wrapper = newMockDirectory();
         final CountDownLatch cleanupCompleted = new CountDownLatch(1);
         MockDirectoryWrapper.Failure fail = new MockDirectoryWrapper.Failure() {
-            public boolean didFail1;
-            public boolean didFail2;
 
             @Override
             public void eval(MockDirectoryWrapper dir) throws IOException {
-                if (!doFail) {
-                    return;
-                }
-                if (callStackContainsAnyOf("mergeTerms") && !didFail1) {
-                    didFail1 = true;
-                    throw new IOException("No space left on device");
-                }
-                if (callStackContains(LiveDocsFormat.class, "writeLiveDocs") && !didFail2) {
-                    didFail2 = true;
+                if (callStackContainsAnyOf("mergeTerms")) {
                     throw new IOException("No space left on device");
                 }
             }
@@ -3537,7 +3502,6 @@ public void onFailedEngine(String reason, Exception e) {
             segments = engine.segments(false);
             assertThat(segments.size(), equalTo(2));
 
-            fail.setDoFail();
             // Close the store so that unreferenced file cleanup will fail.
             store.close();
 
diff --git a/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
index 0d8ef6784a28c..393c448330142 100644
--- a/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
+++ b/server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java
@@ -44,13 +44,17 @@
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.DocValuesFieldExistsQuery;
 import org.apache.lucene.search.FuzzyQuery;
+import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.MultiTermQuery;
 import org.apache.lucene.search.NormsFieldExistsQuery;
+import org.apache.lucene.search.Query;
 import org.apache.lucene.search.RegexpQuery;
 import org.apache.lucene.search.TermInSetQuery;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TermRangeQuery;
+import org.apache.lucene.search.WildcardQuery;
 import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.Operations;
 import org.opensearch.OpenSearchException;
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
@@ -128,14 +132,29 @@ public void testTermsQuery() {
         List<BytesRef> terms = new ArrayList<>();
         terms.add(new BytesRef("foo"));
         terms.add(new BytesRef("bar"));
-        assertEquals(new TermInSetQuery("field", terms), ft.termsQuery(Arrays.asList("foo", "bar"), null));
+        Query expected = new IndexOrDocValuesQuery(
+            new TermInSetQuery("field", terms),
+            new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, "field", terms)
+        );
+        assertEquals(expected, ft.termsQuery(Arrays.asList("foo", "bar"), null));
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        Query expectedIndex = new TermInSetQuery("field", terms);
+        assertEquals(expectedIndex, onlyIndexed.termsQuery(Arrays.asList("foo", "bar"), null));
+
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query expectedDocValues = new TermInSetQuery(MultiTermQuery.DOC_VALUES_REWRITE, "field", terms);
+        assertEquals(expectedDocValues, onlyDocValues.termsQuery(Arrays.asList("foo", "bar"), null));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
             () -> unsearchable.termsQuery(Arrays.asList("foo", "bar"), null)
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
     }
 
     public void testExistsQuery() {
@@ -157,9 +176,36 @@ public void testExistsQuery() {
 
     public void testRangeQuery() {
         MappedFieldType ft = new KeywordFieldType("field");
+
+        Query indexExpected = new TermRangeQuery("field", BytesRefs.toBytesRef("foo"), BytesRefs.toBytesRef("bar"), true, false);
+        Query dvExpected = new TermRangeQuery(
+            "field",
+            BytesRefs.toBytesRef("foo"),
+            BytesRefs.toBytesRef("bar"),
+            true,
+            false,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+
+        Query expected = new IndexOrDocValuesQuery(indexExpected, dvExpected);
+        Query actual = ft.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC);
+        assertEquals(expected, actual);
+
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC));
+
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
+        IllegalArgumentException e = expectThrows(
+            IllegalArgumentException.class,
+            () -> unsearchable.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC)
+        );
+
         assertEquals(
-            new TermRangeQuery("field", BytesRefs.toBytesRef("foo"), BytesRefs.toBytesRef("bar"), true, false),
-            ft.rangeQuery("foo", "bar", true, false, null, null, null, MOCK_QSC)
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
         );
 
         OpenSearchException ee = expectThrows(
@@ -175,16 +221,37 @@ public void testRangeQuery() {
     public void testRegexpQuery() {
         MappedFieldType ft = new KeywordFieldType("field");
         assertEquals(
-            new RegexpQuery(new Term("field", "foo.*")),
+            new IndexOrDocValuesQuery(
+                new RegexpQuery(new Term("field", "foo.*")),
+                new RegexpQuery(new Term("field", "foo.*"), 0, 0, RegexpQuery.DEFAULT_PROVIDER, 10, MultiTermQuery.DOC_VALUES_REWRITE)
+            ),
             ft.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC)
         );
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query indexExpected = new RegexpQuery(new Term("field", "foo.*"));
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query dvExpected = new RegexpQuery(
+            new Term("field", "foo.*"),
+            0,
+            0,
+            RegexpQuery.DEFAULT_PROVIDER,
+            10,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.regexpQuery("foo.*", 0, 0, 10, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
             () -> unsearchable.regexpQuery("foo.*", 0, 0, 10, null, MOCK_QSC)
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
 
         OpenSearchException ee = expectThrows(
             OpenSearchException.class,
@@ -200,12 +267,26 @@ public void testFuzzyQuery() {
             ft.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC)
         );
 
-        MappedFieldType unsearchable = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        Query indexExpected = new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true);
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC));
+
+        Query dvExpected = new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE);
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(
+            dvExpected,
+            onlyDocValues.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC)
+        );
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
         IllegalArgumentException e = expectThrows(
             IllegalArgumentException.class,
-            () -> unsearchable.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC)
+            () -> unsearchable.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC)
+        );
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
         );
-        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
 
         OpenSearchException ee = expectThrows(
             OpenSearchException.class,
@@ -214,6 +295,47 @@ public void testFuzzyQuery() {
         assertEquals("[fuzzy] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", ee.getMessage());
     }
 
+    public void testWildCardQuery() {
+        MappedFieldType ft = new KeywordFieldType("field");
+        Query expected = new IndexOrDocValuesQuery(
+            new WildcardQuery(new Term("field", new BytesRef("foo*"))),
+            new WildcardQuery(
+                new Term("field", new BytesRef("foo*")),
+                Operations.DEFAULT_DETERMINIZE_WORK_LIMIT,
+                MultiTermQuery.DOC_VALUES_REWRITE
+            )
+        );
+        assertEquals(expected, ft.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query indexExpected = new WildcardQuery(new Term("field", new BytesRef("foo*")));
+        MappedFieldType onlyIndexed = new KeywordFieldType("field", true, false, Collections.emptyMap());
+        assertEquals(indexExpected, onlyIndexed.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC));
+
+        Query dvExpected = new WildcardQuery(
+            new Term("field", new BytesRef("foo*")),
+            Operations.DEFAULT_DETERMINIZE_WORK_LIMIT,
+            MultiTermQuery.DOC_VALUES_REWRITE
+        );
+        MappedFieldType onlyDocValues = new KeywordFieldType("field", false, true, Collections.emptyMap());
+        assertEquals(dvExpected, onlyDocValues.wildcardQuery("foo*", MultiTermQuery.DOC_VALUES_REWRITE, MOCK_QSC));
+
+        MappedFieldType unsearchable = new KeywordFieldType("field", false, false, Collections.emptyMap());
+        IllegalArgumentException e = expectThrows(
+            IllegalArgumentException.class,
+            () -> unsearchable.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC)
+        );
+        assertEquals(
+            "Cannot search on field [field] since it is both not indexed, and does not have doc_values " + "enabled.",
+            e.getMessage()
+        );
+
+        OpenSearchException ee = expectThrows(
+            OpenSearchException.class,
+            () -> ft.wildcardQuery("foo*", MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE, MOCK_QSC_DISALLOW_EXPENSIVE)
+        );
+        assertEquals("[wildcard] queries cannot be executed when 'search.allow_expensive_queries' is set to false.", ee.getMessage());
+    }
+
     public void testNormalizeQueries() {
         MappedFieldType ft = new KeywordFieldType("field");
         assertEquals(new TermQuery(new Term("field", new BytesRef("FOO"))), ft.termQuery("FOO", null));
diff --git a/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java b/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
index e1391393f44fa..39f5bb313fe9e 100644
--- a/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
+++ b/server/src/test/java/org/opensearch/index/query/MultiMatchQueryBuilderTests.java
@@ -304,10 +304,16 @@ public void testToQueryBooleanPrefixMultipleFields() throws IOException {
                 } else if (disjunct instanceof PrefixQuery) {
                     final PrefixQuery secondDisjunct = (PrefixQuery) disjunct;
                     assertThat(secondDisjunct.getPrefix(), equalTo(new Term(KEYWORD_FIELD_NAME, "foo bar")));
+                } else if (disjunct instanceof IndexOrDocValuesQuery) {
+                    final IndexOrDocValuesQuery iodvqDisjunct = (IndexOrDocValuesQuery) disjunct;
+                    assertThat(iodvqDisjunct.getIndexQuery().toString(), equalTo("mapped_string_2:foo bar*"));
                 } else {
                     throw new AssertionError();
                 }
-                assertThat(disjunct, either(instanceOf(BooleanQuery.class)).or(instanceOf(PrefixQuery.class)));
+                assertThat(
+                    disjunct,
+                    either(instanceOf(BooleanQuery.class)).or(instanceOf(PrefixQuery.class)).or(instanceOf(IndexOrDocValuesQuery.class))
+                );
             }
         }
     }
diff --git a/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java b/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
index 28c95ddf13fc4..7971591e82bab 100644
--- a/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
+++ b/server/src/test/java/org/opensearch/index/seqno/ReplicationTrackerTests.java
@@ -1907,6 +1907,86 @@ public void testSegmentReplicationCheckpointTracking() {
         }
     }
 
+    public void testSegmentReplicationCheckpointForRelocatingPrimary() {
+        Settings settings = Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
+        final long initialClusterStateVersion = randomNonNegativeLong();
+        final int numberOfActiveAllocationsIds = randomIntBetween(2, 2);
+        final int numberOfInitializingIds = randomIntBetween(2, 2);
+        final Tuple<Set<AllocationId>, Set<AllocationId>> activeAndInitializingAllocationIds = randomActiveAndInitializingAllocationIds(
+            numberOfActiveAllocationsIds,
+            numberOfInitializingIds
+        );
+        final Set<AllocationId> activeAllocationIds = activeAndInitializingAllocationIds.v1();
+        final Set<AllocationId> initializingIds = activeAndInitializingAllocationIds.v2();
+
+        AllocationId targetAllocationId = initializingIds.iterator().next();
+        AllocationId primaryId = activeAllocationIds.iterator().next();
+        String relocatingToNodeId = nodeIdFromAllocationId(targetAllocationId);
+
+        logger.info("--> activeAllocationIds {} Primary {}", activeAllocationIds, primaryId.getId());
+        logger.info("--> initializingIds {} Target {}", initializingIds, targetAllocationId);
+
+        final ShardId shardId = new ShardId("test", "_na_", 0);
+        final IndexShardRoutingTable.Builder builder = new IndexShardRoutingTable.Builder(shardId);
+        for (final AllocationId initializingId : initializingIds) {
+            boolean primaryRelocationTarget = initializingId.equals(targetAllocationId);
+            builder.addShard(
+                TestShardRouting.newShardRouting(
+                    shardId,
+                    nodeIdFromAllocationId(initializingId),
+                    null,
+                    primaryRelocationTarget,
+                    ShardRoutingState.INITIALIZING,
+                    initializingId
+                )
+            );
+        }
+        builder.addShard(
+            TestShardRouting.newShardRouting(
+                shardId,
+                nodeIdFromAllocationId(primaryId),
+                relocatingToNodeId,
+                true,
+                ShardRoutingState.STARTED,
+                primaryId
+            )
+        );
+        IndexShardRoutingTable routingTable = builder.build();
+        final ReplicationTracker tracker = newTracker(primaryId, settings);
+        tracker.updateFromClusterManager(initialClusterStateVersion, ids(activeAllocationIds), routingTable);
+        tracker.activatePrimaryMode(NO_OPS_PERFORMED);
+        assertThat(tracker.getReplicationGroup().getInSyncAllocationIds(), equalTo(ids(activeAllocationIds)));
+        assertThat(tracker.getReplicationGroup().getRoutingTable(), equalTo(routingTable));
+        assertTrue(activeAllocationIds.stream().allMatch(a -> tracker.getTrackedLocalCheckpointForShard(a.getId()).inSync));
+        initializingIds.forEach(aId -> markAsTrackingAndInSyncQuietly(tracker, aId.getId(), NO_OPS_PERFORMED));
+
+        final StoreFileMetadata segment_1 = new StoreFileMetadata("segment_1", 5L, "abcd", Version.LATEST);
+        final ReplicationCheckpoint initialCheckpoint = new ReplicationCheckpoint(
+            tracker.shardId(),
+            0L,
+            1,
+            1,
+            5L,
+            Codec.getDefault().getName(),
+            Map.of("segment_1", segment_1)
+        );
+        tracker.setLatestReplicationCheckpoint(initialCheckpoint);
+        tracker.startReplicationLagTimers(initialCheckpoint);
+
+        final Set<String> expectedIds = initializingIds.stream()
+            .filter(id -> id.equals(targetAllocationId))
+            .map(AllocationId::getId)
+            .collect(Collectors.toSet());
+
+        Set<SegmentReplicationShardStats> groupStats = tracker.getSegmentReplicationStats();
+        assertEquals(expectedIds.size(), groupStats.size());
+        for (SegmentReplicationShardStats shardStat : groupStats) {
+            assertEquals(1, shardStat.getCheckpointsBehindCount());
+            assertEquals(5L, shardStat.getBytesBehindCount());
+            assertTrue(shardStat.getCurrentReplicationLagMillis() >= shardStat.getCurrentReplicationTimeMillis());
+        }
+    }
+
     public void testSegmentReplicationCheckpointTrackingInvalidAllocationIDs() {
         Settings settings = Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
         final long initialClusterStateVersion = randomNonNegativeLong();
diff --git a/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java b/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
index fa3cf7676f55c..dc2111fdcfc56 100644
--- a/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
+++ b/server/src/test/java/org/opensearch/index/shard/IndexShardTests.java
@@ -2850,6 +2850,7 @@ public void testSyncSegmentsFromGivenRemoteSegmentStore() throws IOException {
         indexDoc(source, "_doc", "1");
         indexDoc(source, "_doc", "2");
         source.refresh("test");
+        assertTrue("At lease one remote sync should have been completed", source.isRemoteSegmentStoreInSync());
         assertDocs(source, "1", "2");
         indexDoc(source, "_doc", "3");
         source.refresh("test");
diff --git a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
index 7b02635525264..252f3975bab25 100644
--- a/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
+++ b/server/src/test/java/org/opensearch/indices/replication/SegmentReplicationTargetServiceTests.java
@@ -55,7 +55,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.BiConsumer;
 
-import static org.junit.Assert.assertEquals;
+import static org.opensearch.index.seqno.SequenceNumbers.NO_OPS_PERFORMED;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.atLeastOnce;
@@ -247,6 +247,7 @@ public void testAlreadyOnNewCheckpoint() {
         SegmentReplicationTargetService spy = spy(sut);
         spy.onNewCheckpoint(replicaShard.getLatestReplicationCheckpoint(), replicaShard);
         verify(spy, times(0)).startReplication(any(), any(), any());
+        verify(spy, times(1)).updateVisibleCheckpoint(NO_OPS_PERFORMED, replicaShard);
     }
 
     @TestLogging(reason = "Getting trace logs from replication package", value = "org.opensearch.indices.replication:TRACE")
diff --git a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
index d44bd3831281f..98d2a7e84d672 100644
--- a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
+++ b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
@@ -41,6 +41,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.AtomicArray;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.common.breaker.CircuitBreaker;
 import org.opensearch.core.common.breaker.NoopCircuitBreaker;
 import org.opensearch.core.common.bytes.BytesArray;
@@ -194,7 +195,7 @@ public void testResolveIndexDefaultPipeline() throws Exception {
         service.applyClusterState(cce);
 
         SearchRequest searchRequest = new SearchRequest("my_index").source(SearchSourceBuilder.searchSource().size(5));
-        PipelinedRequest pipelinedRequest = service.resolvePipeline(searchRequest);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(service.resolvePipeline(searchRequest));
         assertEquals("p1", pipelinedRequest.getPipeline().getId());
         assertEquals(10, pipelinedRequest.source().size());
 
@@ -597,7 +598,7 @@ public void testTransformRequest() throws Exception {
         SearchSourceBuilder sourceBuilder = new SearchSourceBuilder().query(new TermQueryBuilder("foo", "bar")).size(size);
         SearchRequest request = new SearchRequest("_index").source(sourceBuilder).pipeline("p1");
 
-        PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(request);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(searchPipelineService.resolvePipeline(request));
 
         assertEquals(2 * size, pipelinedRequest.source().size());
         assertEquals(size, request.source().size());
@@ -641,19 +642,57 @@ public void testTransformResponse() throws Exception {
         // First try without specifying a pipeline, which should be a no-op.
         SearchRequest searchRequest = new SearchRequest();
         PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
-        SearchResponse notTransformedResponse = pipelinedRequest.transformResponse(searchResponse);
+        SearchResponse notTransformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         assertSame(searchResponse, notTransformedResponse);
 
         // Now apply a pipeline
         searchRequest = new SearchRequest().pipeline("p1");
         pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
-        SearchResponse transformedResponse = pipelinedRequest.transformResponse(searchResponse);
+        SearchResponse transformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         assertEquals(size, transformedResponse.getHits().getHits().length);
         for (int i = 0; i < size; i++) {
             assertEquals(2.0, transformedResponse.getHits().getHits()[i].getScore(), 0.0001f);
         }
     }
 
+    /**
+     * Helper to synchronously apply a response pipeline, returning the transformed response.
+     */
+    private static SearchResponse syncTransformResponse(PipelinedRequest pipelinedRequest, SearchResponse searchResponse) throws Exception {
+        SearchResponse[] responseBox = new SearchResponse[1];
+        Exception[] exceptionBox = new Exception[1];
+        ActionListener<SearchResponse> responseListener = pipelinedRequest.transformResponseListener(ActionListener.wrap(r -> {
+            responseBox[0] = r;
+        }, e -> { exceptionBox[0] = e; }));
+        responseListener.onResponse(searchResponse);
+
+        if (exceptionBox[0] != null) {
+            throw exceptionBox[0];
+        }
+        return responseBox[0];
+    }
+
+    /**
+     * Helper to synchronously apply a request pipeline, returning the transformed request.
+     */
+    private static PipelinedRequest syncTransformRequest(PipelinedRequest request) throws Exception {
+        PipelinedRequest[] requestBox = new PipelinedRequest[1];
+        Exception[] exceptionBox = new Exception[1];
+
+        request.transformRequest(ActionListener.wrap(r -> requestBox[0] = (PipelinedRequest) r, e -> exceptionBox[0] = e));
+        if (exceptionBox[0] != null) {
+            throw exceptionBox[0];
+        }
+        return requestBox[0];
+    }
+
+    /**
+     * Helper to synchronously apply a request pipeline and response pipeline, returning the transformed response.
+     */
+    private static SearchResponse syncExecutePipeline(PipelinedRequest request, SearchResponse response) throws Exception {
+        return syncTransformResponse(syncTransformRequest(request), response);
+    }
+
     public void testTransformSearchPhase() {
         SearchPipelineService searchPipelineService = createWithProcessors();
         SearchPipelineMetadata metadata = new SearchPipelineMetadata(
@@ -875,7 +914,7 @@ public void testInlinePipeline() throws Exception {
         SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
 
         // Verify pipeline
-        PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
+        PipelinedRequest pipelinedRequest = syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest));
         Pipeline pipeline = pipelinedRequest.getPipeline();
         assertEquals(SearchPipelineService.AD_HOC_PIPELINE_ID, pipeline.getId());
         assertEquals(1, pipeline.getSearchRequestProcessors().size());
@@ -894,7 +933,7 @@ public void testInlinePipeline() throws Exception {
         SearchResponseSections searchResponseSections = new SearchResponseSections(searchHits, null, null, false, false, null, 0);
         SearchResponse searchResponse = new SearchResponse(searchResponseSections, null, 1, 1, 0, 10, null, null);
 
-        SearchResponse transformedResponse = pipeline.transformResponse(searchRequest, searchResponse);
+        SearchResponse transformedResponse = syncTransformResponse(pipelinedRequest, searchResponse);
         for (int i = 0; i < size; i++) {
             assertEquals(2.0, transformedResponse.getHits().getHits()[i].getScore(), 0.0001);
         }
@@ -946,7 +985,10 @@ public void testExceptionOnRequestProcessing() {
         SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
 
         // Exception thrown when processing the request
-        expectThrows(SearchPipelineProcessingException.class, () -> searchPipelineService.resolvePipeline(searchRequest));
+        expectThrows(
+            SearchPipelineProcessingException.class,
+            () -> syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest))
+        );
     }
 
     public void testExceptionOnResponseProcessing() throws Exception {
@@ -974,10 +1016,10 @@ public void testExceptionOnResponseProcessing() throws Exception {
 
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
         // Exception thrown when processing response
-        expectThrows(SearchPipelineProcessingException.class, () -> pipelinedRequest.transformResponse(response));
+        expectThrows(SearchPipelineProcessingException.class, () -> syncTransformResponse(pipelinedRequest, response));
     }
 
-    public void testCatchExceptionOnRequestProcessing() throws IllegalAccessException {
+    public void testCatchExceptionOnRequestProcessing() throws Exception {
         SearchRequestProcessor throwingRequestProcessor = new FakeRequestProcessor("throwing_request", null, null, true, r -> {
             throw new RuntimeException();
         });
@@ -1008,7 +1050,7 @@ public void testCatchExceptionOnRequestProcessing() throws IllegalAccessExceptio
                     "The exception from request processor [throwing_request] in the search pipeline [_ad_hoc_pipeline] was ignored"
                 )
             );
-            PipelinedRequest pipelinedRequest = searchPipelineService.resolvePipeline(searchRequest);
+            syncTransformRequest(searchPipelineService.resolvePipeline(searchRequest));
             mockAppender.assertAllExpectationsMatched();
         }
     }
@@ -1048,7 +1090,7 @@ public void testCatchExceptionOnResponseProcessing() throws Exception {
                     "The exception from response processor [throwing_response] in the search pipeline [_ad_hoc_pipeline] was ignored"
                 )
             );
-            pipelinedRequest.transformResponse(response);
+            syncTransformResponse(pipelinedRequest, response);
             mockAppender.assertAllExpectationsMatched();
         }
     }
@@ -1078,15 +1120,15 @@ public void testStats() throws Exception {
         SearchRequest request = new SearchRequest();
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
 
-        searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")), response);
         expectThrows(
             SearchPipelineProcessingException.class,
-            () -> searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")).transformResponse(response)
+            () -> syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")), response)
         );
-        searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")), response);
         expectThrows(
             SearchPipelineProcessingException.class,
-            () -> searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")).transformResponse(response)
+            () -> syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")), response)
         );
 
         SearchPipelineStats stats = searchPipelineService.stats();
@@ -1164,12 +1206,12 @@ public void testStatsEnabledIgnoreFailure() throws Exception {
         SearchRequest request = new SearchRequest();
         SearchResponse response = new SearchResponse(null, null, 0, 0, 0, 0, null, null);
 
-        searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_request_pipeline")), response);
         // Caught Exception here
-        searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")).transformResponse(response);
-        searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_request_pipeline")), response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("good_response_pipeline")), response);
         // Caught Exception here
-        searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")).transformResponse(response);
+        syncExecutePipeline(searchPipelineService.resolvePipeline(request.pipeline("bad_response_pipeline")), response);
 
         // when ignoreFailure enabled, the search pipelines will all succeed.
         SearchPipelineStats stats = searchPipelineService.stats();
@@ -1273,8 +1315,8 @@ private SearchPipelineService getSearchPipelineService(
     }
 
     private static void assertPipelineStats(OperationStats stats, long count, long failed) {
-        assertEquals(stats.getCount(), count);
-        assertEquals(stats.getFailedCount(), failed);
+        assertEquals(count, stats.getCount());
+        assertEquals(failed, stats.getFailedCount());
     }
 
     public void testAdHocRejectingProcessor() {
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
index ad27d9834f159..0c6c81103922f 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
@@ -1666,6 +1666,11 @@ public void indexRandom(boolean forceRefresh, boolean dummyDocuments, boolean ma
             }
         }
         assertThat(actualErrors, emptyIterable());
+
+        if (dummyDocuments) {
+            bogusIds.addAll(indexRandomForMultipleSlices(indicesArray));
+        }
+
         if (!bogusIds.isEmpty()) {
             // delete the bogus types again - it might trigger merges or at least holes in the segments and enforces deleted docs!
             for (List<String> doc : bogusIds) {
@@ -1683,6 +1688,52 @@ public void indexRandom(boolean forceRefresh, boolean dummyDocuments, boolean ma
         }
     }
 
+    /*
+    * This method ingests bogus documents for the given indices such that multiple slices
+    * are formed. This is useful for testing with the concurrent search use-case as it creates
+    * multiple slices based on segment count.
+    * @param indices         the indices in which bogus documents should be ingested
+    * */
+    protected Set<List<String>> indexRandomForMultipleSlices(String... indices) throws InterruptedException {
+        Set<List<String>> bogusIds = new HashSet<>();
+        int refreshCount = randomIntBetween(2, 3);
+        for (String index : indices) {
+            int numDocs = getNumShards(index).totalNumShards * randomIntBetween(2, 10);
+            while (refreshCount-- > 0) {
+                final CopyOnWriteArrayList<Tuple<IndexRequestBuilder, Exception>> errors = new CopyOnWriteArrayList<>();
+                List<CountDownLatch> inFlightAsyncOperations = new ArrayList<>();
+                for (int i = 0; i < numDocs; i++) {
+                    String id = "bogus_doc_" + randomRealisticUnicodeOfLength(between(1, 10)) + dummmyDocIdGenerator.incrementAndGet();
+                    IndexRequestBuilder indexRequestBuilder = client().prepareIndex()
+                        .setIndex(index)
+                        .setId(id)
+                        .setSource("{}", MediaTypeRegistry.JSON)
+                        .setRouting(id);
+                    indexRequestBuilder.execute(
+                        new PayloadLatchedActionListener<>(indexRequestBuilder, newLatch(inFlightAsyncOperations), errors)
+                    );
+                    bogusIds.add(Arrays.asList(index, id));
+                }
+                for (CountDownLatch operation : inFlightAsyncOperations) {
+                    operation.await();
+                }
+                final List<Exception> actualErrors = new ArrayList<>();
+                for (Tuple<IndexRequestBuilder, Exception> tuple : errors) {
+                    Throwable t = ExceptionsHelper.unwrapCause(tuple.v2());
+                    if (t instanceof OpenSearchRejectedExecutionException) {
+                        logger.debug("Error indexing doc: " + t.getMessage() + ", reindexing.");
+                        tuple.v1().execute().actionGet(); // re-index if rejected
+                    } else {
+                        actualErrors.add(tuple.v2());
+                    }
+                }
+                assertThat(actualErrors, emptyIterable());
+                refresh(index);
+            }
+        }
+        return bogusIds;
+    }
+
     private final AtomicInteger dummmyDocIdGenerator = new AtomicInteger();
 
     /** Disables an index block for the specified index */
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
index 8490ee4fc39bc..b5ff30deecf5c 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchTestCase.java
@@ -175,6 +175,8 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import reactor.core.scheduler.Schedulers;
+
 import static java.util.Collections.emptyMap;
 import static org.opensearch.core.common.util.CollectionUtils.arrayAsArrayList;
 import static org.hamcrest.Matchers.empty;
@@ -225,6 +227,7 @@ public static void resetPortCounter() {
 
     @Override
     public void tearDown() throws Exception {
+        Schedulers.shutdownNow();
         FeatureFlagSetter.clear();
         super.tearDown();
     }
diff --git a/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java b/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
index 636064d8e4f9d..f8813a8c5afa9 100644
--- a/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/ParameterizedOpenSearchIntegTestCase.java
@@ -13,6 +13,8 @@
 import org.junit.After;
 import org.junit.Before;
 
+import static org.opensearch.search.SearchService.CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING;
+
 /**
  * Base class for running the tests with parameterization of the dynamic settings
  * For any class that wants to use parameterization, use @ParametersFactory to generate
@@ -44,4 +46,10 @@ public void afterTests() {
         dynamicSettings.keySet().forEach(settingsToUnset::putNull);
         client().admin().cluster().prepareUpdateSettings().setPersistentSettings(settingsToUnset).get();
     }
+
+    public void indexRandomForConcurrentSearch(String... indices) throws InterruptedException {
+        if (dynamicSettings.get(CLUSTER_CONCURRENT_SEGMENT_SEARCH_SETTING.getKey()).equals("true")) {
+            indexRandomForMultipleSlices(indices);
+        }
+    }
 }