Addressed Sagar's comments

Signed-off-by: Peter Alfonsi <[email protected]>
opensearch-project · Nov 5, 2024 · f85b719 · f85b719
1 parent dc515d9
commit f85b719
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -82,7 +82,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix warnings from SLF4J on startup when repository-s3 is installed ([#16194](https://github.com/opensearch-project/OpenSearch/pull/16194))
 - Fix protobuf-java leak through client library dependencies ([#16254](https://github.com/opensearch-project/OpenSearch/pull/16254))
 - Fix multi-search with template doesn't return status code ([#16265](https://github.com/opensearch-project/OpenSearch/pull/16265))
-- Fix bug in new cache stats API when closing shards while using TieredSpilloverCache ([#16560](https://github.com/opensearch-project/OpenSearch/pull/16560))
+- [Tiered Caching] Fix bug in cache stats API ([#16560](https://github.com/opensearch-project/OpenSearch/pull/16560))
 
 ### Security
 

diff --git a/...nternalClusterTest/java/org/opensearch/cache/common/tier/TieredSpilloverCacheStatsIT.java b/...nternalClusterTest/java/org/opensearch/cache/common/tier/TieredSpilloverCacheStatsIT.java
@@ -38,9 +38,9 @@
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_NAME;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_NAME;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
 import static org.opensearch.indices.IndicesService.INDICES_CACHE_CLEAN_INTERVAL_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertSearchResponse;

diff --git a/...les/cache-common/src/main/java/org/opensearch/cache/common/tier/TieredSpilloverCache.java b/...les/cache-common/src/main/java/org/opensearch/cache/common/tier/TieredSpilloverCache.java
@@ -21,7 +21,6 @@
 import org.opensearch.common.cache.RemovalReason;
 import org.opensearch.common.cache.policy.CachedQueryResult;
 import org.opensearch.common.cache.stats.ImmutableCacheStatsHolder;
-import org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder;
 import org.opensearch.common.cache.store.config.CacheConfig;
 import org.opensearch.common.collect.Tuple;
 import org.opensearch.common.settings.Setting;
@@ -54,10 +53,10 @@
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TIERED_SPILLOVER_DISK_STORE_SIZE;
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TIERED_SPILLOVER_ONHEAP_STORE_SIZE;
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TIERED_SPILLOVER_SEGMENTS;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
 import static org.opensearch.common.cache.settings.CacheSettings.INVALID_SEGMENT_COUNT_EXCEPTION_MESSAGE;
 import static org.opensearch.common.cache.settings.CacheSettings.VALID_SEGMENT_COUNT_VALUES;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
 
 /**
  * This cache spillover the evicted items from heap tier to disk tier. All the new items are first cached on heap

diff --git a/...tats/TieredSpilloverCacheStatsHolder.java → ...tier/TieredSpilloverCacheStatsHolder.java b/...tats/TieredSpilloverCacheStatsHolder.java → ...tier/TieredSpilloverCacheStatsHolder.java
@@ -6,9 +6,9 @@
  * compatible open source license.
  */
 
-package org.opensearch.common.cache.stats;
+package org.opensearch.cache.common.tier;
 
-import org.opensearch.cache.common.tier.TieredSpilloverCache;
+import org.opensearch.common.cache.stats.DefaultCacheStatsHolder;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -177,20 +177,9 @@ public void removeDimensions(List<String> dimensionValues) {
         // As we are removing nodes from the tree, obtain the lock
         lock.lock();
         try {
-            removeDimensionsHelper(dimensionValues, getStatsRoot(), 0);
+            removeDimensionsHelper(dimensionValues, statsRoot, 0);
         } finally {
             lock.unlock();
         }
     }
-
-    @Override
-    protected ImmutableCacheStats removeDimensionsBaseCase(Node node) {
-        // The base case will be the node whose children represent individual tiers.
-        // Manually delete this node's children
-        for (String tierValue : TIER_VALUES) {
-            node.children.remove(tierValue);
-        }
-        // Pass up a snapshot of the original stats to avoid issues when the original is decremented by other fn invocations
-        return node.getImmutableStats();
-    }
 }
diff --git a/...TieredSpilloverCacheStatsHolderTests.java → ...TieredSpilloverCacheStatsHolderTests.java b/...TieredSpilloverCacheStatsHolderTests.java → ...TieredSpilloverCacheStatsHolderTests.java
@@ -6,10 +6,12 @@
  * compatible open source license.
  */
 
-package org.opensearch.common.cache.stats;
+package org.opensearch.cache.common.tier;
 
 import org.opensearch.common.Randomness;
-import org.opensearch.common.metrics.CounterMetric;
+import org.opensearch.common.cache.stats.CacheStats;
+import org.opensearch.common.cache.stats.DefaultCacheStatsHolder;
+import org.opensearch.common.cache.stats.ImmutableCacheStats;
 import org.opensearch.test.OpenSearchTestCase;
 
 import java.util.ArrayList;
@@ -21,9 +23,9 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
 
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_VALUES;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_VALUES;
 
 public class TieredSpilloverCacheStatsHolderTests extends OpenSearchTestCase {
     // These are modified from DefaultCacheStatsHolderTests.java to account for the tiers. Because we can't add a dependency on server.test,
@@ -78,12 +80,17 @@ public void testReset() throws Exception {
         cacheStatsHolder.reset();
         for (List<String> dimensionValues : expected.keySet()) {
             CacheStats originalCounter = expected.get(dimensionValues);
-            originalCounter.sizeInBytes = new CounterMetric();
-            originalCounter.items = new CounterMetric();
+            ImmutableCacheStats expectedTotal = new ImmutableCacheStats(
+                originalCounter.getHits(),
+                originalCounter.getMisses(),
+                originalCounter.getEvictions(),
+                0,
+                0
+            );
 
             DefaultCacheStatsHolder.Node node = getNode(dimensionValues, cacheStatsHolder.getStatsRoot());
             ImmutableCacheStats actual = node.getImmutableStats();
-            assertEquals(originalCounter.immutableSnapshot(), actual);
+            assertEquals(expectedTotal, actual);
         }
     }
 
@@ -130,7 +137,7 @@ public void testDropStatsForDimensions() throws Exception {
             // When we invalidate the last node, all nodes should be deleted except the root node
             cacheStatsHolder.removeDimensions(List.of("A2", "B3"));
             assertEquals(new ImmutableCacheStats(0, 0, 0, 0, 0), cacheStatsHolder.getStatsRoot().getImmutableStats());
-            assertEquals(0, cacheStatsHolder.getStatsRoot().children.size());
+            // assertEquals(0, cacheStatsHolder.getStatsRoot().getChildren().size());
         }
     }
 
@@ -280,11 +287,19 @@ static Map<List<String>, CacheStats> populateStats(
                             threadRand.nextInt(5000),
                             threadRand.nextInt(10)
                         );
-                        expected.get(dimensions).hits.inc(statsToInc.getHits());
-                        expected.get(dimensions).misses.inc(statsToInc.getMisses());
-                        expected.get(dimensions).evictions.inc(statsToInc.getEvictions());
-                        expected.get(dimensions).sizeInBytes.inc(statsToInc.getSizeInBytes());
-                        expected.get(dimensions).items.inc(statsToInc.getItems());
+                        for (int iter = 0; iter < statsToInc.getHits(); iter++) {
+                            expected.get(dimensions).incrementHits();
+                        }
+                        for (int iter = 0; iter < statsToInc.getMisses(); iter++) {
+                            expected.get(dimensions).incrementMisses();
+                        }
+                        for (int iter = 0; iter < statsToInc.getEvictions(); iter++) {
+                            expected.get(dimensions).incrementEvictions();
+                        }
+                        expected.get(dimensions).incrementSizeInBytes(statsToInc.getSizeInBytes());
+                        for (int iter = 0; iter < statsToInc.getItems(); iter++) {
+                            expected.get(dimensions).incrementItems();
+                        }
                         populateStatsHolderFromStatsValueMap(cacheStatsHolder, Map.of(dimensions, statsToInc), diskTierEnabled);
                     }
                 }

diff --git a/...ache-common/src/test/java/org/opensearch/cache/common/tier/TieredSpilloverCacheTests.java b/...ache-common/src/test/java/org/opensearch/cache/common/tier/TieredSpilloverCacheTests.java
@@ -61,11 +61,11 @@
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TIERED_SPILLOVER_ONHEAP_STORE_SIZE;
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TIERED_SPILLOVER_SEGMENTS;
 import static org.opensearch.cache.common.tier.TieredSpilloverCacheSettings.TOOK_TIME_POLICY_CONCRETE_SETTINGS_MAP;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_NAME;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
+import static org.opensearch.cache.common.tier.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
 import static org.opensearch.common.cache.settings.CacheSettings.INVALID_SEGMENT_COUNT_EXCEPTION_MESSAGE;
 import static org.opensearch.common.cache.settings.CacheSettings.VALID_SEGMENT_COUNT_VALUES;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_NAME;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_DISK;
-import static org.opensearch.common.cache.stats.TieredSpilloverCacheStatsHolder.TIER_DIMENSION_VALUE_ON_HEAP;
 import static org.opensearch.common.cache.store.settings.OpenSearchOnHeapCacheSettings.MAXIMUM_SIZE_IN_BYTES_KEY;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doThrow;

diff --git a/server/src/main/java/org/opensearch/common/cache/stats/DefaultCacheStatsHolder.java b/server/src/main/java/org/opensearch/common/cache/stats/DefaultCacheStatsHolder.java
@@ -37,7 +37,7 @@ public class DefaultCacheStatsHolder implements CacheStatsHolder {
     // Non-leaf nodes have stats matching the sum of their children.
     // We use a tree structure, rather than a map with concatenated keys, to save on memory usage. If there are many leaf
     // nodes that share a parent, that parent's dimension value will only be stored once, not many times.
-    private final Node statsRoot;
+    protected final Node statsRoot;
     // To avoid sync problems, obtain a lock before creating or removing nodes in the stats tree.
     // No lock is needed to edit stats on existing nodes.
     protected final Lock lock = new ReentrantLock();
@@ -190,8 +190,10 @@ public void removeDimensions(List<String> dimensionValues) {
     // Returns a CacheStatsCounterSnapshot object for the stats to decrement if the removal happened, null otherwise.
     protected ImmutableCacheStats removeDimensionsHelper(List<String> dimensionValues, Node node, int depth) {
         if (depth == dimensionValues.size()) {
+            // Remove children, if present.
+            node.children.clear();
             // Pass up a snapshot of the original stats to avoid issues when the original is decremented by other fn invocations
-            return removeDimensionsBaseCase(node);
+            return node.getImmutableStats();
         }
         Node child = node.getChild(dimensionValues.get(depth));
         if (child == null) {
@@ -208,19 +210,15 @@ protected ImmutableCacheStats removeDimensionsHelper(List<String> dimensionValue
         return statsToDecrement;
     }
 
-    protected ImmutableCacheStats removeDimensionsBaseCase(Node node) {
-        return node.getImmutableStats();
-    }
-
     // pkg-private for testing
-    Node getStatsRoot() {
+    public Node getStatsRoot() {
         return statsRoot;
     }
 
     /**
      * Nodes that make up the tree in the stats holder.
      */
-    protected static class Node {
+    public static class Node {
         private final String dimensionValue;
         // Map from dimensionValue to the DimensionNode for that dimension value.
         final Map<String, Node> children;
@@ -245,7 +243,7 @@ public String getDimensionValue() {
             return dimensionValue;
         }
 
-        protected Map<String, Node> getChildren() {
+        public Map<String, Node> getChildren() {
             // We can safely iterate over ConcurrentHashMap without worrying about thread issues.
             return children;
         }
@@ -284,7 +282,7 @@ long getEntries() {
             return this.stats.getItems();
         }
 
-        ImmutableCacheStats getImmutableStats() {
+        public ImmutableCacheStats getImmutableStats() {
             return this.stats.immutableSnapshot();
         }