Fix shard level rescoring disabled setting flag

Signed-off-by: Naveen Tatikonda <[email protected]>

CHANGELOG.md

@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * Fixing the bug when a segment has no vector field present for disk based vector search (#2282)[https://github.com/opensearch-project/k-NN/pull/2282]
 * Allow validation for non knn index only after 2.17.0 (#2315)[https://github.com/opensearch-project/k-NN/pull/2315]
 * Release query vector memory after execution (#2346)[https://github.com/opensearch-project/k-NN/pull/2346]
+* Fix shard level rescoring disabled setting flag (#2352)[https://github.com/opensearch-project/k-NN/pull/2352]
 ### Infrastructure
 * Updated C++ version in JNI from c++11 to c++17 [#2259](https://github.com/opensearch-project/k-NN/pull/2259)
 * Upgrade bytebuddy and objenesis version to match OpenSearch core and, update github ci runner for macos [#2279](https://github.com/opensearch-project/k-NN/pull/2279)

src/main/java/org/opensearch/knn/index/KNNSettings.java

@@ -577,7 +577,7 @@ public static Integer getFilteredExactSearchThreshold(final String indexName) {
             .getAsInt(ADVANCED_FILTERED_EXACT_SEARCH_THRESHOLD, ADVANCED_FILTERED_EXACT_SEARCH_THRESHOLD_DEFAULT_VALUE);
     }
 
-    public static boolean isShardLevelRescoringEnabledForDiskBasedVector(String indexName) {
+    public static boolean isShardLevelRescoringDisabledForDiskBasedVector(String indexName) {
         return KNNSettings.state().clusterService.state()
             .getMetadata()
             .index(indexName)

src/main/java/org/opensearch/knn/index/query/nativelib/NativeEngineKnnVectorQuery.java

@@ -63,11 +63,11 @@ public Weight createWeight(IndexSearcher indexSearcher, ScoreMode scoreMode, flo
         if (rescoreContext == null) {
             perLeafResults = doSearch(indexSearcher, leafReaderContexts, knnWeight, finalK);
         } else {
-            boolean isShardLevelRescoringEnabled = KNNSettings.isShardLevelRescoringEnabledForDiskBasedVector(knnQuery.getIndexName());
+            boolean isShardLevelRescoringDisabled = KNNSettings.isShardLevelRescoringDisabledForDiskBasedVector(knnQuery.getIndexName());
             int dimension = knnQuery.getQueryVector().length;
-            int firstPassK = rescoreContext.getFirstPassK(finalK, isShardLevelRescoringEnabled, dimension);
+            int firstPassK = rescoreContext.getFirstPassK(finalK, isShardLevelRescoringDisabled, dimension);
             perLeafResults = doSearch(indexSearcher, leafReaderContexts, knnWeight, firstPassK);
-            if (isShardLevelRescoringEnabled == true) {
+            if (isShardLevelRescoringDisabled == false) {
                 ResultUtil.reduceToTopK(perLeafResults, firstPassK);
             }
 

src/main/java/org/opensearch/knn/index/query/rescore/RescoreContext.java

@@ -61,17 +61,17 @@ public static RescoreContext getDefault() {
      * based on the vector dimension if shard-level rescoring is disabled.
      *
      * @param finalK The final number of results to return for the entire shard.
-     * @param isShardLevelRescoringEnabled A boolean flag indicating whether shard-level rescoring is enabled.
-     *                                     If true, the dimension-based oversampling logic is bypassed.
+     * @param isShardLevelRescoringDisabled A boolean flag indicating whether shard-level rescoring is disabled.
+     *                                     If false, the dimension-based oversampling logic is bypassed.
      * @param dimension The dimension of the vector. This is used to determine the oversampling factor when
      *                  shard-level rescoring is disabled.
      * @return The number of results to return for the first pass of rescoring, adjusted by the oversample factor.
      */
-    public int getFirstPassK(int finalK, boolean isShardLevelRescoringEnabled, int dimension) {
+    public int getFirstPassK(int finalK, boolean isShardLevelRescoringDisabled, int dimension) {
         // Only apply default dimension-based oversampling logic when:
         // 1. Shard-level rescoring is disabled
         // 2. The oversample factor was not provided by the user
-        if (!isShardLevelRescoringEnabled && !userProvided) {
+        if (isShardLevelRescoringDisabled && !userProvided) {
             // Apply new dimension-based oversampling logic when shard-level rescoring is disabled
             if (dimension >= DIMENSION_THRESHOLD_1000) {
                 oversampleFactor = OVERSAMPLE_FACTOR_1000;  // No oversampling for dimensions >= 1000

src/test/java/org/opensearch/knn/index/KNNSettingsTests.java

@@ -159,15 +159,15 @@ public void testGetEfSearch_whenEFSearchValueSetByUser_thenReturnValue() {
     }
 
     @SneakyThrows
-    public void testShardLevelRescoringEnabled_whenNoValuesProvidedByUser_thenDefaultSettingsUsed() {
+    public void testShardLevelRescoringDisabled_whenNoValuesProvidedByUser_thenDefaultSettingsUsed() {
         Node mockNode = createMockNode(Collections.emptyMap());
         mockNode.start();
         ClusterService clusterService = mockNode.injector().getInstance(ClusterService.class);
         mockNode.client().admin().cluster().state(new ClusterStateRequest()).actionGet();
         mockNode.client().admin().indices().create(new CreateIndexRequest(INDEX_NAME)).actionGet();
         KNNSettings.state().setClusterService(clusterService);
 
-        boolean shardLevelRescoringDisabled = KNNSettings.isShardLevelRescoringEnabledForDiskBasedVector(INDEX_NAME);
+        boolean shardLevelRescoringDisabled = KNNSettings.isShardLevelRescoringDisabledForDiskBasedVector(INDEX_NAME);
         mockNode.close();
         assertFalse(shardLevelRescoringDisabled);
     }
@@ -188,7 +188,7 @@ public void testShardLevelRescoringDisabled_whenValueProvidedByUser_thenSettingA
 
         mockNode.client().admin().indices().updateSettings(new UpdateSettingsRequest(rescoringDisabledSetting, INDEX_NAME)).actionGet();
 
-        boolean shardLevelRescoringDisabled = KNNSettings.isShardLevelRescoringEnabledForDiskBasedVector(INDEX_NAME);
+        boolean shardLevelRescoringDisabled = KNNSettings.isShardLevelRescoringDisabledForDiskBasedVector(INDEX_NAME);
         mockNode.close();
         assertEquals(userDefinedRescoringDisabled, shardLevelRescoringDisabled);
     }

src/test/java/org/opensearch/knn/index/query/nativelib/NativeEngineKNNVectorQueryTests.java

@@ -183,7 +183,7 @@ public void testRescoreWhenShardLevelRescoringEnabled() {
         ) {
 
             // When shard-level re-scoring is enabled
-            mockedKnnSettings.when(() -> KNNSettings.isShardLevelRescoringEnabledForDiskBasedVector(any())).thenReturn(true);
+            mockedKnnSettings.when(() -> KNNSettings.isShardLevelRescoringDisabledForDiskBasedVector(any())).thenReturn(false);
 
             // Mock ResultUtil to return valid TopDocs
             mockedResultUtil.when(() -> ResultUtil.resultMapToTopDocs(any(), anyInt()))
@@ -265,7 +265,7 @@ public void testRescore() {
         ) {
 
             // When shard-level re-scoring is enabled
-            mockedKnnSettings.when(() -> KNNSettings.isShardLevelRescoringEnabledForDiskBasedVector(any())).thenReturn(true);
+            mockedKnnSettings.when(() -> KNNSettings.isShardLevelRescoringDisabledForDiskBasedVector(any())).thenReturn(false);
 
             mockedResultUtil.when(() -> ResultUtil.reduceToTopK(any(), anyInt())).thenAnswer(InvocationOnMock::callRealMethod);
             mockedResultUtil.when(() -> ResultUtil.resultMapToDocIds(any(), anyInt())).thenAnswer(InvocationOnMock::callRealMethod);