Star tree mapping changes (opensearch-project#14605)

* Star tree mapping changes with feature flag
---------
Signed-off-by: Bharathwaj G <bharath78910@gmail.com>

Author: bharath-techie

distribution/src/config/opensearch.yml

@@ -125,3 +125,7 @@ ${path.logs}
 # Gates the functionality of enabling Opensearch to use pluggable caches with respective store names via setting.
 #
 #opensearch.experimental.feature.pluggable.caching.enabled: false
+#
+# Gates the functionality of star tree index, which improves the performance of search aggregations.
+#
+#opensearch.experimental.feature.composite_index.star_tree.enabled: true

server/src/internalClusterTest/java/org/opensearch/index/mapper/StarTreeMapperIT.java

@@ -85,6 +85,7 @@
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.index.IndexService;
 import org.opensearch.index.IndexSettings;
+import org.opensearch.index.compositeindex.CompositeIndexValidator;
 import org.opensearch.index.mapper.DocumentMapper;
 import org.opensearch.index.mapper.MapperService;
 import org.opensearch.index.mapper.MapperService.MergeReason;
@@ -1318,6 +1319,10 @@ private static void updateIndexMappingsAndBuildSortOrder(
             }
         }
 
+        if (mapperService.isCompositeIndexPresent()) {
+            CompositeIndexValidator.validate(mapperService, indexService.getCompositeIndexSettings(), indexService.getIndexSettings());
+        }
+
         if (sourceMetadata == null) {
             // now that the mapping is merged we can validate the index sort.
             // we cannot validate for index shrinking since the mapping is empty

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

@@ -55,6 +55,7 @@
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.index.Index;
 import org.opensearch.index.IndexService;
+import org.opensearch.index.compositeindex.CompositeIndexValidator;
 import org.opensearch.index.mapper.DocumentMapper;
 import org.opensearch.index.mapper.MapperService;
 import org.opensearch.index.mapper.MapperService.MergeReason;
@@ -282,6 +283,7 @@ private ClusterState applyRequest(
                     // first, simulate: just call merge and ignore the result
                     existingMapper.merge(newMapper.mapping(), MergeReason.MAPPING_UPDATE);
                 }
+
             }
             Metadata.Builder builder = Metadata.builder(metadata);
             boolean updated = false;
@@ -291,7 +293,7 @@ private ClusterState applyRequest(
                 // we use the exact same indexService and metadata we used to validate above here to actually apply the update
                 final Index index = indexMetadata.getIndex();
                 final MapperService mapperService = indexMapperServices.get(index);
-
+                boolean isCompositeFieldPresent = !mapperService.getCompositeFieldTypes().isEmpty();
                 CompressedXContent existingSource = null;
                 DocumentMapper existingMapper = mapperService.documentMapper();
                 if (existingMapper != null) {
@@ -302,6 +304,14 @@ private ClusterState applyRequest(
                     mappingUpdateSource,
                     MergeReason.MAPPING_UPDATE
                 );
+
+                CompositeIndexValidator.validate(
+                    mapperService,
+                    indicesService.getCompositeIndexSettings(),
+                    mapperService.getIndexSettings(),
+                    isCompositeFieldPresent
+                );
+
                 CompressedXContent updatedSource = mergedMapper.mappingSource();
 
                 if (existingSource != null) {

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

@@ -115,6 +115,7 @@
 import org.opensearch.index.ShardIndexingPressureMemoryManager;
 import org.opensearch.index.ShardIndexingPressureSettings;
 import org.opensearch.index.ShardIndexingPressureStore;
+import org.opensearch.index.compositeindex.CompositeIndexSettings;
 import org.opensearch.index.remote.RemoteStorePressureSettings;
 import org.opensearch.index.remote.RemoteStoreStatsTrackerFactory;
 import org.opensearch.index.store.remote.filecache.FileCacheSettings;
@@ -754,7 +755,10 @@ public void apply(Settings value, Settings current, Settings previous) {
                 RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_HASH_ALGORITHM_SETTING,
                 RemoteStoreSettings.CLUSTER_REMOTE_MAX_TRANSLOG_READERS,
                 RemoteStoreSettings.CLUSTER_REMOTE_STORE_TRANSLOG_METADATA,
-                SearchService.CLUSTER_ALLOW_DERIVED_FIELD_SETTING
+                SearchService.CLUSTER_ALLOW_DERIVED_FIELD_SETTING,
+
+                // Composite index settings
+                CompositeIndexSettings.STAR_TREE_INDEX_ENABLED_SETTING
             )
         )
     );

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

@@ -37,6 +37,7 @@ protected FeatureFlagSettings(
         FeatureFlags.TIERED_REMOTE_INDEX_SETTING,
         FeatureFlags.REMOTE_STORE_MIGRATION_EXPERIMENTAL_SETTING,
         FeatureFlags.PLUGGABLE_CACHE_SETTING,
-        FeatureFlags.REMOTE_PUBLICATION_EXPERIMENTAL_SETTING
+        FeatureFlags.REMOTE_PUBLICATION_EXPERIMENTAL_SETTING,
+        FeatureFlags.STAR_TREE_INDEX_SETTING
     );
 }

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

@@ -52,6 +52,7 @@
 import org.opensearch.index.SearchSlowLog;
 import org.opensearch.index.TieredMergePolicyProvider;
 import org.opensearch.index.cache.bitset.BitsetFilterCache;
+import org.opensearch.index.compositeindex.datacube.startree.StarTreeIndexSettings;
 import org.opensearch.index.engine.EngineConfig;
 import org.opensearch.index.fielddata.IndexFieldDataService;
 import org.opensearch.index.mapper.FieldMapper;
@@ -239,6 +240,15 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 // Settings for concurrent segment search
                 IndexSettings.INDEX_CONCURRENT_SEGMENT_SEARCH_SETTING,
                 IndexSettings.ALLOW_DERIVED_FIELDS,
+
+                // Settings for star tree index
+                StarTreeIndexSettings.STAR_TREE_DEFAULT_MAX_LEAF_DOCS,
+                StarTreeIndexSettings.STAR_TREE_MAX_DIMENSIONS_SETTING,
+                StarTreeIndexSettings.STAR_TREE_MAX_FIELDS_SETTING,
+                StarTreeIndexSettings.DEFAULT_METRICS_LIST,
+                StarTreeIndexSettings.DEFAULT_DATE_INTERVALS,
+                StarTreeIndexSettings.STAR_TREE_MAX_DATE_INTERVALS_SETTING,
+
                 // validate that built-in similarities don't get redefined
                 Setting.groupSetting("index.similarity.", (s) -> {
                     Map<String, Settings> groups = s.getAsGroups();

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

@@ -100,6 +100,13 @@ public class FeatureFlags {
         Property.NodeScope
     );
 
+    /**
+     * Gates the functionality of star tree index, which improves the performance of search
+     * aggregations.
+     */
+    public static final String STAR_TREE_INDEX = "opensearch.experimental.feature.composite_index.star_tree.enabled";
+    public static final Setting<Boolean> STAR_TREE_INDEX_SETTING = Setting.boolSetting(STAR_TREE_INDEX, false, Property.NodeScope);
+
     private static final List<Setting<Boolean>> ALL_FEATURE_FLAG_SETTINGS = List.of(
         REMOTE_STORE_MIGRATION_EXPERIMENTAL_SETTING,
         EXTENSIONS_SETTING,
@@ -108,7 +115,8 @@ public class FeatureFlags {
         DATETIME_FORMATTER_CACHING_SETTING,
         TIERED_REMOTE_INDEX_SETTING,
         PLUGGABLE_CACHE_SETTING,
-        REMOTE_PUBLICATION_EXPERIMENTAL_SETTING
+        REMOTE_PUBLICATION_EXPERIMENTAL_SETTING,
+        STAR_TREE_INDEX_SETTING
     );
     /**
      * Should store the settings from opensearch.yml.

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

@@ -66,6 +66,7 @@
 import org.opensearch.index.cache.query.DisabledQueryCache;
 import org.opensearch.index.cache.query.IndexQueryCache;
 import org.opensearch.index.cache.query.QueryCache;
+import org.opensearch.index.compositeindex.CompositeIndexSettings;
 import org.opensearch.index.engine.Engine;
 import org.opensearch.index.engine.EngineConfigFactory;
 import org.opensearch.index.engine.EngineFactory;
@@ -311,6 +312,7 @@ public Iterator<Setting<?>> settings() {
     private final BooleanSupplier allowExpensiveQueries;
     private final Map<String, IndexStorePlugin.RecoveryStateFactory> recoveryStateFactories;
     private final FileCache fileCache;
+    private final CompositeIndexSettings compositeIndexSettings;
 
     /**
      * Construct the index module for the index with the specified index settings. The index module contains extension points for plugins
@@ -330,7 +332,8 @@ public IndexModule(
         final BooleanSupplier allowExpensiveQueries,
         final IndexNameExpressionResolver expressionResolver,
         final Map<String, IndexStorePlugin.RecoveryStateFactory> recoveryStateFactories,
-        final FileCache fileCache
+        final FileCache fileCache,
+        final CompositeIndexSettings compositeIndexSettings
     ) {
         this.indexSettings = indexSettings;
         this.analysisRegistry = analysisRegistry;
@@ -343,6 +346,7 @@ public IndexModule(
         this.expressionResolver = expressionResolver;
         this.recoveryStateFactories = recoveryStateFactories;
         this.fileCache = fileCache;
+        this.compositeIndexSettings = compositeIndexSettings;
     }
 
     public IndexModule(
@@ -364,6 +368,7 @@ public IndexModule(
             allowExpensiveQueries,
             expressionResolver,
             recoveryStateFactories,
+            null,
             null
         );
     }
@@ -739,7 +744,8 @@ public IndexService newIndexService(
                 clusterDefaultRefreshIntervalSupplier,
                 recoverySettings,
                 remoteStoreSettings,
-                fileCache
+                fileCache,
+                compositeIndexSettings
             );
             success = true;
             return indexService;

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

@@ -73,6 +73,7 @@
 import org.opensearch.index.cache.IndexCache;
 import org.opensearch.index.cache.bitset.BitsetFilterCache;
 import org.opensearch.index.cache.query.QueryCache;
+import org.opensearch.index.compositeindex.CompositeIndexSettings;
 import org.opensearch.index.engine.Engine;
 import org.opensearch.index.engine.EngineConfigFactory;
 import org.opensearch.index.engine.EngineFactory;
@@ -192,6 +193,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     private final RecoverySettings recoverySettings;
     private final RemoteStoreSettings remoteStoreSettings;
     private final FileCache fileCache;
+    private final CompositeIndexSettings compositeIndexSettings;
 
     public IndexService(
         IndexSettings indexSettings,
@@ -228,7 +230,8 @@ public IndexService(
         Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier,
         RecoverySettings recoverySettings,
         RemoteStoreSettings remoteStoreSettings,
-        FileCache fileCache
+        FileCache fileCache,
+        CompositeIndexSettings compositeIndexSettings
     ) {
         super(indexSettings);
         this.allowExpensiveQueries = allowExpensiveQueries;
@@ -306,6 +309,7 @@ public IndexService(
         this.translogFactorySupplier = translogFactorySupplier;
         this.recoverySettings = recoverySettings;
         this.remoteStoreSettings = remoteStoreSettings;
+        this.compositeIndexSettings = compositeIndexSettings;
         this.fileCache = fileCache;
         updateFsyncTaskIfNecessary();
     }
@@ -381,6 +385,7 @@ public IndexService(
             clusterDefaultRefreshIntervalSupplier,
             recoverySettings,
             remoteStoreSettings,
+            null,
             null
         );
     }
@@ -1110,6 +1115,10 @@ private void rescheduleRefreshTasks() {
         }
     }
 
+    public CompositeIndexSettings getCompositeIndexSettings() {
+        return compositeIndexSettings;
+    }
+
     /**
      * Shard Store Deleter Interface
      *