Remove Reader Writer Split experimental feature flag

server/src/internalClusterTest/java/org/opensearch/action/admin/indices/scale/searchonly/ScaleIndexIT.java

@@ -18,7 +18,6 @@
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
@@ -41,11 +40,6 @@ public class ScaleIndexIT extends RemoteStoreBaseIntegTestCase {
 
     private static final String TEST_INDEX = "test_scale_index";
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     public Settings indexSettings() {
         return Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
     }

server/src/internalClusterTest/java/org/opensearch/cluster/allocation/SearchReplicaAllocationIT.java

@@ -12,7 +12,6 @@
 import org.opensearch.cluster.routing.IndexShardRoutingTable;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -25,11 +24,6 @@
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class SearchReplicaAllocationIT extends RemoteStoreBaseIntegTestCase {
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     public void testSearchReplicaAllocatedToDedicatedSearchNode() {
         internalCluster().startClusterManagerOnlyNode();
         String primaryNode = internalCluster().startDataOnlyNode();

server/src/internalClusterTest/java/org/opensearch/cluster/allocation/SearchReplicaAwarenessAllocationIT.java

@@ -19,7 +19,6 @@
 import org.opensearch.cluster.routing.allocation.AwarenessReplicaBalance;
 import org.opensearch.cluster.routing.allocation.decider.AwarenessAllocationDecider;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -40,11 +39,6 @@ public class SearchReplicaAwarenessAllocationIT extends RemoteStoreBaseIntegTest
 
     private final Logger logger = LogManager.getLogger(SearchReplicaAwarenessAllocationIT.class);
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     public void testAllocationAwarenessZones() {
         Settings commonSettings = Settings.builder()
             .put(AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_FORCE_GROUP_SETTING.getKey() + "zone.values", "a,b")

server/src/internalClusterTest/java/org/opensearch/cluster/metadata/AutoExpandSearchReplicasIT.java

@@ -11,7 +11,6 @@
 import org.opensearch.cluster.routing.UnassignedInfo;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
 import org.opensearch.test.InternalTestCluster;
@@ -22,11 +21,6 @@
 @OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
 public class AutoExpandSearchReplicasIT extends RemoteStoreBaseIntegTestCase {
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     public void testAutoExpandSearchReplica() throws Exception {
         String indexName = "test";
         internalCluster().startClusterManagerOnlyNode();

server/src/internalClusterTest/java/org/opensearch/cluster/metadata/MetadataIndexStateServiceIT.java

@@ -11,7 +11,6 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
@@ -28,11 +27,6 @@ public class MetadataIndexStateServiceIT extends RemoteStoreBaseIntegTestCase {
 
     private static final String TEST_INDEX = "test_open_close_index";
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     public void testIndexCloseAndOpen() throws Exception {
         internalCluster().startClusterManagerOnlyNode();
         internalCluster().startDataOnlyNodes(2);

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

@@ -21,7 +21,6 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.SegmentReplicationPerGroupStats;
 import org.opensearch.index.SegmentReplicationShardStats;
 import org.opensearch.indices.recovery.RecoveryState;
@@ -72,11 +71,6 @@ public Settings indexSettings() {
             .build();
     }
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, true).build();
-    }
-
     public void testReplication() throws Exception {
         internalCluster().startClusterManagerOnlyNode();
         final String primary = internalCluster().startDataOnlyNode();

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

@@ -16,7 +16,6 @@
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.metadata.Metadata;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteSnapshotIT;
@@ -39,11 +38,6 @@ public class SearchReplicaRestoreIT extends RemoteSnapshotIT {
     private static final String FS_REPOSITORY_TYPE = "fs";
     private static final int DOC_COUNT = 10;
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, true).build();
-    }
-
     public void testSearchReplicaRestore_WhenSnapshotOnSegRep_RestoreOnDocRepWithSearchReplica() throws Exception {
         bootstrapIndexWithOutSearchReplicas(ReplicationType.SEGMENT);
         createRepoAndSnapshot(REPOSITORY_NAME, FS_REPOSITORY_TYPE, SNAPSHOT_NAME, INDEX_NAME);

server/src/internalClusterTest/java/org/opensearch/indices/settings/SearchOnlyReplicaIT.java

@@ -18,7 +18,6 @@
 import org.opensearch.cluster.routing.Preference;
 import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.query.QueryBuilders;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.remotestore.RemoteStoreBaseIntegTestCase;
@@ -40,11 +39,6 @@ public class SearchOnlyReplicaIT extends RemoteStoreBaseIntegTestCase {
 
     private static final String TEST_INDEX = "test_index";
 
-    @Override
-    protected Settings featureFlagSettings() {
-        return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL, Boolean.TRUE).build();
-    }
-
     private final String expectedFailureMessage = "To set index.number_of_search_replicas, index.replication.type must be set to SEGMENT";
 
     @Override

server/src/main/java/org/opensearch/cluster/ClusterModule.java

@@ -87,7 +87,6 @@
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Setting.Property;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.core.ParseField;
@@ -391,9 +390,7 @@ public static Collection<AllocationDecider> createAllocationDeciders(
         addAllocationDecider(deciders, new SnapshotInProgressAllocationDecider());
         addAllocationDecider(deciders, new RestoreInProgressAllocationDecider());
         addAllocationDecider(deciders, new FilterAllocationDecider(settings, clusterSettings));
-        if (FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING.get(settings)) {
-            addAllocationDecider(deciders, new SearchReplicaAllocationDecider());
-        }
+        addAllocationDecider(deciders, new SearchReplicaAllocationDecider());
         addAllocationDecider(deciders, new SameShardAllocationDecider(settings, clusterSettings));
         addAllocationDecider(deciders, new DiskThresholdDecider(settings, clusterSettings));
         addAllocationDecider(deciders, new ThrottlingAllocationDecider(settings, clusterSettings));

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

@@ -1092,9 +1092,7 @@ static Settings aggregateIndexSettings(
         validateRefreshIntervalSettings(request.settings(), clusterSettings);
         validateTranslogFlushIntervalSettingsForCompositeIndex(request.settings(), clusterSettings);
         validateTranslogDurabilitySettings(request.settings(), clusterSettings, settings);
-        if (FeatureFlags.isEnabled(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING)) {
-            validateSearchOnlyReplicasSettings(indexSettings);
-        }
+        validateSearchOnlyReplicasSettings(indexSettings);
         validateIndexTotalPrimaryShardsPerNodeSetting(indexSettings);
         return indexSettings;
     }

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

@@ -58,7 +58,6 @@
 import org.opensearch.common.settings.IndexScopedSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.action.ActionListener;
 import org.opensearch.core.index.Index;
 import org.opensearch.index.IndexSettings;
@@ -296,9 +295,7 @@ public ClusterState execute(ClusterState currentState) {
                     }
 
                     if (IndexMetadata.INDEX_NUMBER_OF_SEARCH_REPLICAS_SETTING.exists(openSettings)) {
-                        if (FeatureFlags.isEnabled(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING)) {
-                            validateSearchReplicaCountSettings(normalizedSettings, request.indices(), currentState);
-                        }
+                        validateSearchReplicaCountSettings(normalizedSettings, request.indices(), currentState);
                         final int updatedNumberOfSearchReplicas = IndexMetadata.INDEX_NUMBER_OF_SEARCH_REPLICAS_SETTING.get(openSettings);
                         if (preserveExisting == false) {
                             for (Index index : request.indices()) {

server/src/main/java/org/opensearch/cluster/node/DiscoveryNode.java

@@ -607,7 +607,8 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     }
 
     private static Map<String, DiscoveryNodeRole> rolesToMap(final Stream<DiscoveryNodeRole> roles) {
-        return Collections.unmodifiableMap(roles.collect(Collectors.toMap(DiscoveryNodeRole::roleName, Function.identity())));
+        Stream<DiscoveryNodeRole> rolesWithSearch = Stream.concat(roles, Stream.of(DiscoveryNodeRole.SEARCH_ROLE));
+        return Collections.unmodifiableMap(rolesWithSearch.collect(Collectors.toMap(DiscoveryNodeRole::roleName, Function.identity())));
     }
 
     private static Map<String, DiscoveryNodeRole> roleMap = rolesToMap(DiscoveryNodeRole.BUILT_IN_ROLES.stream());

server/src/main/java/org/opensearch/cluster/node/DiscoveryNodeRole.java

@@ -342,7 +342,7 @@ public void validateRole(List<DiscoveryNodeRole> roles) {
      * The built-in node roles.
      */
     public static SortedSet<DiscoveryNodeRole> BUILT_IN_ROLES = Collections.unmodifiableSortedSet(
-        new TreeSet<>(Arrays.asList(DATA_ROLE, INGEST_ROLE, CLUSTER_MANAGER_ROLE, REMOTE_CLUSTER_CLIENT_ROLE, WARM_ROLE, SEARCH_ROLE))
+        new TreeSet<>(Arrays.asList(DATA_ROLE, INGEST_ROLE, CLUSTER_MANAGER_ROLE, REMOTE_CLUSTER_CLIENT_ROLE, WARM_ROLE))
     );
 
     /**

server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java

@@ -133,7 +133,6 @@ public class OperationRouting {
     private volatile boolean isStrictWeightedShardRouting;
     private volatile boolean ignoreWeightedRouting;
     private volatile boolean isStrictSearchOnlyShardRouting;
-    private final boolean isReaderWriterSplitEnabled;
 
     public OperationRouting(Settings settings, ClusterSettings clusterSettings) {
         // whether to ignore awareness attributes when routing requests
@@ -156,7 +155,6 @@ public OperationRouting(Settings settings, ClusterSettings clusterSettings) {
         clusterSettings.addSettingsUpdateConsumer(STRICT_WEIGHTED_SHARD_ROUTING_ENABLED, this::setStrictWeightedShardRouting);
         clusterSettings.addSettingsUpdateConsumer(IGNORE_WEIGHTED_SHARD_ROUTING, this::setIgnoreWeightedRouting);
         clusterSettings.addSettingsUpdateConsumer(STRICT_SEARCH_REPLICA_ROUTING_ENABLED, this::setStrictSearchOnlyShardRouting);
-        this.isReaderWriterSplitEnabled = FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING.get(settings);
     }
 
     void setUseAdaptiveReplicaSelection(boolean useAdaptiveReplicaSelection) {
@@ -277,11 +275,9 @@ public GroupShardsIterator<ShardIterator> searchShards(
                 preference = Preference.PRIMARY_FIRST.type();
             }
 
-            if (isReaderWriterSplitEnabled) {
-                if (preference == null || preference.isEmpty()) {
-                    if (indexMetadataForShard.getNumberOfSearchOnlyReplicas() > 0 && isStrictSearchOnlyShardRouting) {
-                        preference = Preference.SEARCH_REPLICA.type();
-                    }
+            if (preference == null || preference.isEmpty()) {
+                if (indexMetadataForShard.getNumberOfSearchOnlyReplicas() > 0 && isStrictSearchOnlyShardRouting) {
+                    preference = Preference.SEARCH_REPLICA.type();
                 }
             }
 

server/src/main/java/org/opensearch/cluster/routing/ShardRouting.java

@@ -38,7 +38,6 @@
 import org.opensearch.cluster.routing.allocation.allocator.BalancedShardsAllocator;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.annotation.PublicApi;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.core.common.io.stream.Writeable;
@@ -912,9 +911,7 @@ public String shortSummary() {
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         XContentBuilder fieldBuilder = builder.startObject().field("state", state()).field("primary", primary());
-        if (FeatureFlags.isEnabled(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL)) {
-            fieldBuilder.field("searchOnly", isSearchOnly());
-        }
+        fieldBuilder.field("searchOnly", isSearchOnly());
         fieldBuilder.field("node", currentNodeId())
             .field("relocating_node", relocatingNodeId())
             .field("shard", id())

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

@@ -37,7 +37,6 @@ protected FeatureFlagSettings(
         FeatureFlags.REMOTE_STORE_MIGRATION_EXPERIMENTAL_SETTING,
         FeatureFlags.STAR_TREE_INDEX_SETTING,
         FeatureFlags.APPLICATION_BASED_CONFIGURATION_TEMPLATES_SETTING,
-        FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING,
         FeatureFlags.TERM_VERSION_PRECOMMIT_ENABLE_SETTING,
         FeatureFlags.ARROW_STREAMS_SETTING
     );

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

@@ -270,6 +270,9 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 IndexMetadata.INGESTION_SOURCE_PARAMS_SETTING,
                 IndexMetadata.INGESTION_SOURCE_ERROR_STRATEGY_SETTING,
 
+                // Settings for search replica
+                IndexMetadata.INDEX_NUMBER_OF_SEARCH_REPLICAS_SETTING,
+
                 // validate that built-in similarities don't get redefined
                 Setting.groupSetting("index.similarity.", (s) -> {
                     Map<String, Settings> groups = s.getAsGroups();
@@ -295,9 +298,7 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
     public static final Map<String, List<Setting>> FEATURE_FLAGGED_INDEX_SETTINGS = Map.of(
         FeatureFlags.WRITABLE_WARM_INDEX_EXPERIMENTAL_FLAG,
         // TODO: Create a separate feature flag for hot tiering index state.
-        List.of(IndexModule.INDEX_STORE_LOCALITY_SETTING, IndexModule.INDEX_TIERING_STATE, IndexModule.IS_WARM_INDEX_SETTING),
-        FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL,
-        List.of(IndexMetadata.INDEX_NUMBER_OF_SEARCH_REPLICAS_SETTING)
+        List.of(IndexModule.INDEX_STORE_LOCALITY_SETTING, IndexModule.INDEX_TIERING_STATE, IndexModule.IS_WARM_INDEX_SETTING)
     );
 
     public static final IndexScopedSettings DEFAULT_SCOPED_SETTINGS = new IndexScopedSettings(Settings.EMPTY, BUILT_IN_INDEX_SETTINGS);