Updating changelog and renaming feature flag setting

Signed-off-by: Sagar Upadhyaya <sagar.upadhyaya.121@gmail.com>

CHANGELOG.md

@@ -105,7 +105,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add toString methods to MultiSearchRequest, MultiGetRequest and CreateIndexRequest ([#12163](https://github.com/opensearch-project/OpenSearch/pull/12163))
 - Support for returning scores in matched queries ([#11626](https://github.com/opensearch-project/OpenSearch/pull/11626))
 - Add shard id property to SearchLookup for use in field types provided by plugins ([#1063](https://github.com/opensearch-project/OpenSearch/pull/1063))
-- [Tiered caching] Integrating IndicesRequestCache with CacheService controlled by a feature flag ([#12533](https://github.com/opensearch-project/OpenSearch/pull/12533))
+- [Tiered caching] Make IndicesRequestCache implementation configurable [EXPERIMENTAL] ([#12533](https://github.com/opensearch-project/OpenSearch/pull/12533))
 - Add kuromoji_completion analyzer and filter ([#4835](https://github.com/opensearch-project/OpenSearch/issues/4835))
 
 ### Dependencies

distribution/src/config/opensearch.yml

@@ -121,3 +121,7 @@ ${path.logs}
 # Once there is no observed impact on performance, this feature flag can be removed.
 #
 #opensearch.experimental.optimization.datetime_formatter_caching.enabled: false
+#
+# Gates the functionality of enabling Opensearch to use pluggable caches with respective store names via setting.
+#
+#opensearch.experimental.feature.pluggable.caching.enabled: false

modules/cache-common/src/internalClusterTest/java/org.opensearch.cache.common.tier/TieredSpilloverCacheIT.java

@@ -52,7 +52,7 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
 
     @Override
     protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.TIERED_CACHING, "true").build();
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.PLUGGABLE_CACHE, "true").build();
     }
 
     @Override

server/src/internalClusterTest/java/org/opensearch/indices/IndicesRequestCacheIT.java

@@ -84,7 +84,7 @@ public static Collection<Object[]> parameters() {
 
     @Override
     protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.TIERED_CACHING, "true").build();
+        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.PLUGGABLE_CACHE, "true").build();
     }
 
     @Override

server/src/main/java/org/opensearch/common/settings/ClusterSettings.java

@@ -732,7 +732,7 @@ public void apply(Settings value, Settings current, Settings previous) {
             TelemetrySettings.TRACER_FEATURE_ENABLED_SETTING,
             TelemetrySettings.METRICS_FEATURE_ENABLED_SETTING
         ),
-        List.of(FeatureFlags.TIERED_CACHING),
+        List.of(FeatureFlags.PLUGGABLE_CACHE),
         List.of(CacheSettings.getConcreteSettingForCacheType(CacheType.INDICES_REQUEST_CACHE))
     );
 }

server/src/main/java/org/opensearch/common/settings/FeatureFlagSettings.java

@@ -37,6 +37,6 @@ protected FeatureFlagSettings(
         FeatureFlags.WRITEABLE_REMOTE_INDEX_SETTING,
         FeatureFlags.DOC_ID_FUZZY_SET_SETTING,
         FeatureFlags.REMOTE_STORE_MIGRATION_EXPERIMENTAL_SETTING,
-        FeatureFlags.TIERED_CACHING_SETTING
+        FeatureFlags.PLUGGABLE_CACHE_SETTING
     );
 }

server/src/main/java/org/opensearch/common/util/FeatureFlags.java

@@ -65,9 +65,10 @@ public class FeatureFlags {
     public static final String DOC_ID_FUZZY_SET = "opensearch.experimental.optimize_doc_id_lookup.fuzzy_set.enabled";
 
     /**
-     * Gates the functionality of tiered caching
+     * Gates the functionality of pluggable cache.
+     * Enables OpenSearch to use pluggable caches with respective store names via setting.
      */
-    public static final String TIERED_CACHING = "opensearch.experimental.feature.tiered.caching.enabled";
+    public static final String PLUGGABLE_CACHE = "opensearch.experimental.feature.pluggable.caching.enabled";
 
     /**
      * Should store the settings from opensearch.yml.
@@ -134,5 +135,5 @@ public static boolean isEnabled(Setting<Boolean> featureFlag) {
 
     public static final Setting<Boolean> DOC_ID_FUZZY_SET_SETTING = Setting.boolSetting(DOC_ID_FUZZY_SET, false, Property.NodeScope);
 
-    public static final Setting<Boolean> TIERED_CACHING_SETTING = Setting.boolSetting(TIERED_CACHING, false, Property.NodeScope);
+    public static final Setting<Boolean> PLUGGABLE_CACHE_SETTING = Setting.boolSetting(PLUGGABLE_CACHE, false, Property.NodeScope);
 }

server/src/main/java/org/opensearch/indices/IndicesRequestCache.java

@@ -131,7 +131,7 @@ public final class IndicesRequestCache implements RemovalListener<IndicesRequest
         long sizeInBytes = size.getBytes();
         ToLongBiFunction<Key, BytesReference> weigher = (k, v) -> k.ramBytesUsed() + v.ramBytesUsed();
         this.cacheEntityLookup = cacheEntityFunction;
-        if (FeatureFlags.TIERED_CACHING_SETTING.get(settings)) {
+        if (FeatureFlags.PLUGGABLE_CACHE_SETTING.get(settings)) {
             this.cache = cacheService.createCache(
                 new CacheConfig.Builder<Key, BytesReference>().setSettings(settings)
                     .setWeigher((k, v) -> k.ramBytesUsed() + v.ramBytesUsed())

server/src/test/java/org/opensearch/indices/IndicesRequestCacheTests.java

@@ -144,7 +144,7 @@ public void testBasicOperationsCacheWithFeatureFlag() throws Exception {
         IndexShard indexShard = createIndex("test").getShard(0);
         CacheService cacheService = new CacheModule(new ArrayList<>(), Settings.EMPTY).getCacheService();
         IndicesRequestCache cache = new IndicesRequestCache(
-            Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.TIERED_CACHING, "true").build(),
+            Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.PLUGGABLE_CACHE, "true").build(),
             (shardId -> Optional.of(new IndicesService.IndexShardCacheEntity(indexShard))),
             cacheService
         );