Integrate local recovery with remote store seeding during migration

server/src/internalClusterTest/java/org/opensearch/remotemigration/RemotePrimaryLocalRecoveryIT.java

@@ -0,0 +1,179 @@
+/*
+ * 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.remotemigration;
+
+import org.opensearch.action.admin.indices.stats.ShardStats;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.cluster.node.DiscoveryNode;
+import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.cluster.routing.ShardRouting;
+import org.opensearch.common.blobstore.BlobPath;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.util.FileSystemUtils;
+import org.opensearch.index.remote.RemoteSegmentStats;
+import org.opensearch.index.translog.RemoteTranslogStats;
+import org.opensearch.test.InternalTestCluster;
+import org.opensearch.test.OpenSearchIntegTestCase;
+
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+
+import static org.opensearch.index.remote.RemoteStoreEnums.DataCategory.SEGMENTS;
+import static org.opensearch.index.remote.RemoteStoreEnums.DataType.DATA;
+import static org.opensearch.index.store.RemoteSegmentStoreDirectory.SEGMENT_NAME_UUID_SEPARATOR;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+public class RemotePrimaryLocalRecoveryIT extends MigrationBaseTestCase {
+    String indexName = "idx1";
+    int numOfNodes = randomIntBetween(6, 9);
+
+    /**
+     * Tests local recovery sanity in the happy path flow
+     */
+    public void testLocalRecoveryRollingRestart() throws Exception {
+        triggerRollingRestartForRemoteMigration(0);
+        internalCluster().stopAllNodes();
+    }
+
+    /**
+     * Tests local recovery sanity during remote migration with a node restart in between
+     */
+    public void testLocalRecoveryRollingRestartAndNodeFailure() throws Exception {
+        triggerRollingRestartForRemoteMigration(0);
+
+        DiscoveryNodes discoveryNodes = internalCluster().client().admin().cluster().prepareState().get().getState().getNodes();
+        DiscoveryNode nodeToRestart = (DiscoveryNode) discoveryNodes.getDataNodes().values().toArray()[randomIntBetween(0, numOfNodes - 4)];
+        internalCluster().restartNode(nodeToRestart.getName());
+
+        Map<ShardRouting, ShardStats> shardStatsMap = internalCluster().client().admin().indices().prepareStats(indexName).get().asMap();
+        for (Map.Entry<ShardRouting, ShardStats> entry : shardStatsMap.entrySet()) {
+            ShardRouting shardRouting = entry.getKey();
+            ShardStats shardStats = entry.getValue();
+            if (nodeToRestart.equals(shardRouting.currentNodeId())) {
+                RemoteSegmentStats remoteSegmentStats = shardStats.getStats().getSegments().getRemoteSegmentStats();
+                assertTrue(remoteSegmentStats.getTotalUploadTime() > 0);
+                assertTrue(remoteSegmentStats.getUploadBytesSucceeded() > 0);
+            }
+
+            assertBusy(() -> {
+                String shardPath = getShardLevelBlobPath(
+                    client(),
+                    indexName,
+                    new BlobPath(),
+                    String.valueOf(shardRouting.getId()),
+                    SEGMENTS,
+                    DATA
+                ).buildAsString();
+                Path segmentDataRepoPath = segmentRepoPath.resolve(shardPath);
+                List<String> segmentsNFilesInRepo = Arrays.stream(FileSystemUtils.files(segmentDataRepoPath))
+                    .filter(path -> path.getFileName().toString().contains("segments_"))
+                    .map(path -> path.getFileName().toString())
+                    .collect(Collectors.toList());
+                Set<String> expectedUniqueSegmentsNFiles = segmentsNFilesInRepo.stream()
+                    .map(fileName -> fileName.split(SEGMENT_NAME_UUID_SEPARATOR)[0])
+                    .collect(Collectors.toSet());
+                assertEquals(
+                    "Expected no duplicate segments_N files in remote but duplicates were found " + segmentsNFilesInRepo,
+                    expectedUniqueSegmentsNFiles.size(),
+                    segmentsNFilesInRepo.size()
+                );
+            }, 90, TimeUnit.SECONDS);
+        }
+
+        internalCluster().stopAllNodes();
+    }
+
+    /**
+     * Tests local recovery flow sanity in the happy path flow with replicas in place
+     */
+    public void testLocalRecoveryFlowWithReplicas() throws Exception {
+        triggerRollingRestartForRemoteMigration(randomIntBetween(1, 2));
+        internalCluster().stopAllNodes();
+    }
+
+    /**
+     * Helper method to run a rolling restart for migration to remote backed cluster
+     */
+    private void triggerRollingRestartForRemoteMigration(int replicaCount) throws Exception {
+        internalCluster().startClusterManagerOnlyNodes(3);
+        internalCluster().startNodes(numOfNodes - 3);
+
+        // create index
+        Settings indexSettings = Settings.builder()
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, replicaCount)
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, randomIntBetween(1, 10))
+            .build();
+        createIndex(indexName, indexSettings);
+        ensureGreen(indexName);
+        indexBulk(indexName, randomIntBetween(100, 10000));
+        refresh(indexName);
+        indexBulk(indexName, randomIntBetween(100, 10000));
+
+        initDocRepToRemoteMigration();
+
+        // rolling restart
+        final Settings remoteNodeAttributes = remoteStoreClusterSettings(
+            REPOSITORY_NAME,
+            segmentRepoPath,
+            REPOSITORY_2_NAME,
+            translogRepoPath
+        );
+        internalCluster().rollingRestart(new InternalTestCluster.RestartCallback() {
+            // Update remote attributes
+            @Override
+            public Settings onNodeStopped(String nodeName) {
+                return remoteNodeAttributes;
+            }
+        });
+        ensureStableCluster(numOfNodes);
+        ensureGreen(TimeValue.timeValueSeconds(90), indexName);
+        assertEquals(internalCluster().size(), numOfNodes);
+
+        // Assert on remote uploads
+        Map<ShardRouting, ShardStats> shardStatsMap = internalCluster().client().admin().indices().prepareStats(indexName).get().asMap();
+        DiscoveryNodes discoveryNodes = internalCluster().client().admin().cluster().prepareState().get().getState().getNodes();
+        shardStatsMap.forEach((shardRouting, shardStats) -> {
+            if (discoveryNodes.get(shardRouting.currentNodeId()).isRemoteStoreNode() && shardRouting.primary()) {
+                RemoteSegmentStats remoteSegmentStats = shardStats.getStats().getSegments().getRemoteSegmentStats();
+                assertTrue(remoteSegmentStats.getTotalUploadTime() > 0);
+                assertTrue(remoteSegmentStats.getUploadBytesSucceeded() > 0);
+            }
+        });
+
+        // Assert on new remote uploads after seeding
+        indexBulk(indexName, randomIntBetween(100, 10000));
+        refresh(indexName);
+        indexBulk(indexName, randomIntBetween(100, 10000));
+        Map<ShardRouting, ShardStats> newShardStatsMap = internalCluster().client().admin().indices().prepareStats(indexName).get().asMap();
+        newShardStatsMap.forEach((shardRouting, shardStats) -> {
+            if (discoveryNodes.get(shardRouting.currentNodeId()).isRemoteStoreNode() && shardRouting.primary()) {
+                RemoteSegmentStats prevRemoteSegmentStats = shardStatsMap.get(shardRouting)
+                    .getStats()
+                    .getSegments()
+                    .getRemoteSegmentStats();
+                RemoteSegmentStats newRemoteSegmentStats = shardStats.getStats().getSegments().getRemoteSegmentStats();
+                assertTrue(newRemoteSegmentStats.getTotalUploadTime() > prevRemoteSegmentStats.getTotalUploadTime());
+                assertTrue(newRemoteSegmentStats.getUploadBytesSucceeded() > prevRemoteSegmentStats.getUploadBytesSucceeded());
+
+                RemoteTranslogStats prevRemoteTranslogStats = shardStatsMap.get(shardRouting)
+                    .getStats()
+                    .getTranslog()
+                    .getRemoteTranslogStats();
+                RemoteTranslogStats newRemoteTranslogStats = shardStats.getStats().getTranslog().getRemoteTranslogStats();
+                assertTrue(newRemoteTranslogStats.getUploadBytesSucceeded() > prevRemoteTranslogStats.getUploadBytesSucceeded());
+            }
+        });
+    }
+}

server/src/main/java/org/opensearch/index/IndexService.java

@@ -500,13 +500,14 @@ public synchronized IndexShard createShard(
                 if (this.indexSettings.isRemoteStoreEnabled()) {
                     remoteDirectory = remoteDirectoryFactory.newDirectory(this.indexSettings, path);
                 } else {
-                    if (sourceNode != null && sourceNode.isRemoteStoreNode() == false) {
+                    if (sourceNode == null || sourceNode.isRemoteStoreNode() == false) {
                         if (routing.primary() == false) {
                             throw new IllegalStateException("Can't migrate a remote shard to replica before primary " + routing.shardId());
                         }
                         logger.info("DocRep shard {} is migrating to remote", shardId);
                         seedRemote = true;
                     }
+
                     remoteDirectory = ((RemoteSegmentStoreDirectoryFactory) remoteDirectoryFactory).newDirectory(
                         RemoteStoreNodeAttribute.getRemoteStoreSegmentRepo(this.indexSettings.getNodeSettings()),
                         this.indexSettings.getUUID(),

server/src/main/java/org/opensearch/index/seqno/ReplicationTracker.java

@@ -1106,8 +1106,8 @@ private ReplicationGroup calculateReplicationGroup() {
         } else {
             newVersion = replicationGroup.getVersion() + 1;
         }
-        assert indexSettings.isRemoteTranslogStoreEnabled()
-            // Handle migration cases. Ignore assertion if any of the shard copies in the replication group is assigned to a remote node
+        assert newVersion == 0 || indexSettings.isRemoteTranslogStoreEnabled()
+        // Handle migration cases. Ignore assertion if any of the shard copies in the replication group is assigned to a remote node
             || (replicationGroup != null
                 && replicationGroup.getReplicationTargets()
                     .stream()

server/src/main/java/org/opensearch/index/shard/IndexShard.java

@@ -436,7 +436,7 @@ public IndexShard(
         logger.debug("state: [CREATED]");
 
         this.checkIndexOnStartup = indexSettings.getValue(IndexSettings.INDEX_CHECK_ON_STARTUP);
-        this.translogConfig = new TranslogConfig(shardId, shardPath().resolveTranslog(), indexSettings, bigArrays, nodeId);
+        this.translogConfig = new TranslogConfig(shardId, shardPath().resolveTranslog(), indexSettings, bigArrays, nodeId, seedRemote);
         final String aId = shardRouting.allocationId().getId();
         final long primaryTerm = indexSettings.getIndexMetadata().primaryTerm(shardId.id());
         this.pendingPrimaryTerm = primaryTerm;
@@ -5000,7 +5000,8 @@ public void syncTranslogFilesFromRemoteTranslog() throws IOException {
             shardPath().resolveTranslog(),
             indexSettings.getRemoteStorePathStrategy(),
             remoteStoreSettings,
-            logger
+            logger,
+            shouldSeedRemoteStore()
         );
     }
 

server/src/main/java/org/opensearch/index/shard/StoreRecovery.java

@@ -650,6 +650,14 @@
                 indexShard.recoveryState().getIndex().setFileDetailsComplete();
             }
             indexShard.openEngineAndRecoverFromTranslog();
+            if (indexShard.shouldSeedRemoteStore()) {
+                indexShard.getThreadPool().executor(ThreadPool.Names.GENERIC).execute(() -> {
+                    logger.info("Attempting to seed Remote Store via local recovery for {}", indexShard.shardId());
+                    indexShard.refresh("remote store migration");
+                });
+                indexShard.waitForRemoteStoreSync();
+                logger.info("Remote Store is now seeded via local recovery for {}", indexShard.shardId());
+            }
             indexShard.getEngine().fillSeqNoGaps(indexShard.getPendingPrimaryTerm());
             indexShard.finalizeRecovery();
             indexShard.postRecovery("post recovery from shard_store");

server/src/main/java/org/opensearch/index/translog/RemoteFsTranslog.java

@@ -120,7 +120,7 @@
             remoteStoreSettings
         );
         try {
-            download(translogTransferManager, location, logger);
+            download(translogTransferManager, location, logger, config.shouldSeedRemote());
             Checkpoint checkpoint = readCheckpoint(location);
             logger.info("Downloaded data from remote translog till maxSeqNo = {}", checkpoint.maxSeqNo);
             this.readers.addAll(recoverFromFiles(checkpoint));
@@ -168,7 +168,8 @@
         Path location,
         RemoteStorePathStrategy pathStrategy,
         RemoteStoreSettings remoteStoreSettings,
-        Logger logger
+        Logger logger,
+        boolean seedRemote
     ) throws IOException {
         assert repository instanceof BlobStoreRepository : String.format(
             Locale.ROOT,
@@ -189,11 +190,12 @@
             pathStrategy,
             remoteStoreSettings
         );
-        RemoteFsTranslog.download(translogTransferManager, location, logger);
+        RemoteFsTranslog.download(translogTransferManager, location, logger, seedRemote);
         logger.trace(remoteTranslogTransferTracker.toString());
     }
 
-    static void download(TranslogTransferManager translogTransferManager, Path location, Logger logger) throws IOException {
+    static void download(TranslogTransferManager translogTransferManager, Path location, Logger logger, boolean seedRemote)
+        throws IOException {
         /*
         In Primary to Primary relocation , there can be concurrent upload and download of translog.
         While translog files are getting downloaded by new primary, it might hence be deleted by the primary
@@ -206,7 +208,7 @@
             boolean success = false;
             long startTimeMs = System.currentTimeMillis();
             try {
-                downloadOnce(translogTransferManager, location, logger);
+                downloadOnce(translogTransferManager, location, logger, seedRemote);
                 success = true;
                 return;
             } catch (FileNotFoundException | NoSuchFileException e) {
@@ -220,7 +222,8 @@
         throw ex;
     }
 
-    private static void downloadOnce(TranslogTransferManager translogTransferManager, Path location, Logger logger) throws IOException {
+    private static void downloadOnce(TranslogTransferManager translogTransferManager, Path location, Logger logger, boolean seedRemote)
+        throws IOException {
         logger.debug("Downloading translog files from remote");
         RemoteTranslogTransferTracker statsTracker = translogTransferManager.getRemoteTranslogTransferTracker();
         long prevDownloadBytesSucceeded = statsTracker.getDownloadBytesSucceeded();
@@ -262,7 +265,9 @@
             logger.debug("No translog files found on remote, checking local filesystem for cleanup");
             if (FileSystemUtils.exists(location.resolve(CHECKPOINT_FILE_NAME))) {
                 final Checkpoint checkpoint = readCheckpoint(location);
-                if (isEmptyTranslog(checkpoint) == false) {
+                if (seedRemote) {
+                    logger.debug("Remote migration ongoing. Retaining the translog on local, skipping clean-up");
+                } else if (isEmptyTranslog(checkpoint) == false) {
                     logger.debug("Translog files exist on local without any metadata in remote, cleaning up these files");
                     // Creating empty translog will cleanup the older un-referenced tranlog files, we don't have to explicitly delete
                     Translog.createEmptyTranslog(location, translogTransferManager.getShardId(), checkpoint);

server/src/main/java/org/opensearch/index/translog/TranslogConfig.java

@@ -59,16 +59,25 @@ public final class TranslogConfig {
     private final Path translogPath;
     private final ByteSizeValue bufferSize;
     private final String nodeId;
+    private final boolean seedRemote;
 
     /**
      * Creates a new TranslogConfig instance
      * @param shardId the shard ID this translog belongs to
      * @param translogPath the path to use for the transaction log files
      * @param indexSettings the index settings used to set internal variables
      * @param bigArrays a bigArrays instance used for temporarily allocating write operations
+     * @param seedRemote boolean denoting whether remote store needs to be seeded as part of remote migration
      */
-    public TranslogConfig(ShardId shardId, Path translogPath, IndexSettings indexSettings, BigArrays bigArrays, String nodeId) {
-        this(shardId, translogPath, indexSettings, bigArrays, DEFAULT_BUFFER_SIZE, nodeId);
+    public TranslogConfig(
+        ShardId shardId,
+        Path translogPath,
+        IndexSettings indexSettings,
+        BigArrays bigArrays,
+        String nodeId,
+        boolean seedRemote
+    ) {
+        this(shardId, translogPath, indexSettings, bigArrays, DEFAULT_BUFFER_SIZE, nodeId, seedRemote);
     }
 
     TranslogConfig(
@@ -77,14 +86,16 @@ public TranslogConfig(ShardId shardId, Path translogPath, IndexSettings indexSet
         IndexSettings indexSettings,
         BigArrays bigArrays,
         ByteSizeValue bufferSize,
-        String nodeId
+        String nodeId,
+        boolean seedRemote
     ) {
         this.bufferSize = bufferSize;
         this.indexSettings = indexSettings;
         this.shardId = shardId;
         this.translogPath = translogPath;
         this.bigArrays = bigArrays;
         this.nodeId = nodeId;
+        this.seedRemote = seedRemote;
     }
 
     /**
@@ -125,4 +136,8 @@ public ByteSizeValue getBufferSize() {
     public String getNodeId() {
         return nodeId;
     }
+
+    public boolean shouldSeedRemote() {
+        return seedRemote;
+    }
 }

server/src/main/java/org/opensearch/index/translog/TruncateTranslogAction.java

@@ -195,7 +195,8 @@ private boolean isTranslogClean(ShardPath shardPath, ClusterState clusterState,
                 translogPath,
                 indexSettings,
                 BigArrays.NON_RECYCLING_INSTANCE,
-                ""
+                "",
+                false
             );
             long primaryTerm = indexSettings.getIndexMetadata().primaryTerm(shardPath.getShardId().id());
             // We open translog to check for corruption, do not clean anything.