[Segment Replication] Introduce new SEGMENT_REPLICATION_EXPERIMENTAL feature flag.

CHANGELOG.md

@@ -86,7 +86,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add wait_for_completion parameter to resize, open, and forcemerge APIs ([#6434](https://github.com/opensearch-project/OpenSearch/pull/6434))
 - [Segment Replication] Apply backpressure when replicas fall behind ([#6563](https://github.com/opensearch-project/OpenSearch/pull/6563))
 - [Remote Store] Integrate remote segment store in peer recovery flow ([#6664](https://github.com/opensearch-project/OpenSearch/pull/6664))
-- [Segment Replication] Add new cluster setting to set replication strategy by default for all indices in cluster. ([#6791](https://github.com/opensearch-project/OpenSearch/pull/6791))
 - Enable sort optimization for all NumericTypes ([#6464](https://github.com/opensearch-project/OpenSearch/pull/6464)
 - Remove 'cluster_manager' role attachment when using 'node.master' deprecated setting ([#6331](https://github.com/opensearch-project/OpenSearch/pull/6331))
 - Add new cluster settings to ignore weighted round-robin routing and fallback to default behaviour. ([#6834](https://github.com/opensearch-project/OpenSearch/pull/6834))

server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java

@@ -47,7 +47,11 @@ public Settings indexSettings() {
 
     @Override
     protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.REPLICATION_TYPE, "true").build();
+        return Settings.builder()
+            .put(super.featureFlagSettings())
+            .put(FeatureFlags.SEGMENT_REPLICATION_EXPERIMENTAL, "true")
+            .put(FeatureFlags.REPLICATION_TYPE, "true")
+            .build();
     }
 
     @Override

server/src/main/java/org/opensearch/cluster/metadata/IndexMetadata.java

@@ -330,10 +330,6 @@ public void validate(final Boolean value, final Map<Setting<?>, Object> settings
                             + INDEX_REPLICATION_TYPE_SETTING.getKey()
                             + " should be set to "
                             + ReplicationType.SEGMENT
-                            + " or "
-                            + CLUSTER_REPLICATION_TYPE_SETTING.getKey()
-                            + " should be set to "
-                            + Boolean.TRUE
                     );
                 }
             }

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

@@ -646,7 +646,7 @@ public void apply(Settings value, Settings current, Settings previous) {
     public static final Map<String, List<Setting>> FEATURE_FLAGGED_CLUSTER_SETTINGS = Map.of(
         FeatureFlags.SEARCHABLE_SNAPSHOT,
         List.of(Node.NODE_SEARCH_CACHE_SIZE_SETTING),
-        FeatureFlags.REPLICATION_TYPE,
+        FeatureFlags.SEGMENT_REPLICATION_EXPERIMENTAL,
         List.of(IndicesService.CLUSTER_REPLICATION_TYPE_SETTING)
     );
 

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

@@ -35,6 +35,7 @@ protected FeatureFlagSettings(
         new HashSet<>(
             Arrays.asList(
                 FeatureFlags.REPLICATION_TYPE_SETTING,
+                FeatureFlags.SEGMENT_REPLICATION_EXPERIMENTAL_SETTING,
                 FeatureFlags.REMOTE_STORE_SETTING,
                 FeatureFlags.SEARCHABLE_SNAPSHOT_SETTING,
                 FeatureFlags.EXTENSIONS_SETTING

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

@@ -27,6 +27,12 @@ public class FeatureFlags {
      */
     public static final String REPLICATION_TYPE = "opensearch.experimental.feature.replication_type.enabled";
 
+    /**
+     * Gates the visibility of the segment replication experimental features that allows users to test unreleased beta features.
+     */
+    public static final String SEGMENT_REPLICATION_EXPERIMENTAL =
+        "opensearch.experimental.feature.segment_replication_experimental.enabled";
+
     /**
      * Gates the visibility of the index setting that allows persisting data to remote store along with local disk.
      * Once the feature is ready for production release, this feature flag can be removed.
@@ -84,6 +90,12 @@ public static boolean isEnabled(String featureFlagName) {
 
     public static final Setting<Boolean> REPLICATION_TYPE_SETTING = Setting.boolSetting(REPLICATION_TYPE, false, Property.NodeScope);
 
+    public static final Setting<Boolean> SEGMENT_REPLICATION_EXPERIMENTAL_SETTING = Setting.boolSetting(
+        SEGMENT_REPLICATION_EXPERIMENTAL,
+        false,
+        Property.NodeScope
+    );
+
     public static final Setting<Boolean> REMOTE_STORE_SETTING = Setting.boolSetting(REMOTE_STORE, false, Property.NodeScope);
 
     public static final Setting<Boolean> SEARCHABLE_SNAPSHOT_SETTING = Setting.boolSetting(SEARCHABLE_SNAPSHOT, false, Property.NodeScope);

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

@@ -751,7 +751,7 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         nodeName = Node.NODE_NAME_SETTING.get(settings);
         this.indexMetadata = indexMetadata;
         numberOfShards = settings.getAsInt(IndexMetadata.SETTING_NUMBER_OF_SHARDS, null);
-        if (FeatureFlags.isEnabled(FeatureFlags.REPLICATION_TYPE)
+        if (FeatureFlags.isEnabled(FeatureFlags.SEGMENT_REPLICATION_EXPERIMENTAL)
             && indexMetadata.isSystem() == false
             && settings.get(IndexMetadata.SETTING_REPLICATION_TYPE) == null) {
             replicationType = IndicesService.CLUSTER_REPLICATION_TYPE_SETTING.get(settings);

server/src/test/java/org/opensearch/index/IndexSettingsTests.java

@@ -869,10 +869,7 @@ public void testEnablingRemoteStoreFailsWhenReplicationTypeIsDocument() {
             IllegalArgumentException.class,
             () -> IndexMetadata.INDEX_REMOTE_STORE_ENABLED_SETTING.get(indexSettings)
         );
-        assertEquals(
-            "To enable index.remote_store.enabled, index.replication.type should be set to SEGMENT or cluster.indices.replication.strategy should be set to true",
-            iae.getMessage()
-        );
+        assertEquals("To enable index.remote_store.enabled, index.replication.type should be set to SEGMENT", iae.getMessage());
     }
 
     public void testEnablingRemoteStoreFailsWhenReplicationTypeIsDefault() {
@@ -881,10 +878,7 @@ public void testEnablingRemoteStoreFailsWhenReplicationTypeIsDefault() {
             IllegalArgumentException.class,
             () -> IndexMetadata.INDEX_REMOTE_STORE_ENABLED_SETTING.get(indexSettings)
         );
-        assertEquals(
-            "To enable index.remote_store.enabled, index.replication.type should be set to SEGMENT or cluster.indices.replication.strategy should be set to true",
-            iae.getMessage()
-        );
+        assertEquals("To enable index.remote_store.enabled, index.replication.type should be set to SEGMENT", iae.getMessage());
     }
 
     public void testRemoteRepositoryDefaultSetting() {