Fix bbq index feature exposure for testing & remove feature flag

muted-tests.yml

@@ -411,8 +411,6 @@ tests:
 - class: org.elasticsearch.xpack.enrich.EnrichIT
   method: testDeleteExistingPipeline
   issue: https://github.com/elastic/elasticsearch/issues/114775
-- class: org.elasticsearch.test.rest.ClientYamlTestSuiteIT
-  issue: https://github.com/elastic/elasticsearch/issues/114787
 - class: org.elasticsearch.xpack.inference.rest.ServerSentEventsRestActionListenerTests
   method: testNoStream
   issue: https://github.com/elastic/elasticsearch/issues/114788

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.vectors/41_knn_search_bbq_hnsw.yml

@@ -1,6 +1,10 @@
 setup:
   - requires:
-      cluster_features: "mapper.vectors.bbq"
+      capabilities:
+        - method: POST
+          path: /_search
+          capabilities: [ bbq_indices ]
+      test_runner_features: capabilities
       reason: 'kNN float to better-binary quantization is required'
   - do:
       indices.create:

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.vectors/42_knn_search_bbq_flat.yml

@@ -1,6 +1,10 @@
 setup:
   - requires:
-      cluster_features: "mapper.vectors.bbq"
+      capabilities:
+        - method: POST
+          path: /_search
+          capabilities: [ bbq_indices ]
+      test_runner_features: capabilities
       reason: 'kNN float to better-binary quantization is required'
   - do:
       indices.create:

server/src/main/java/org/elasticsearch/index/mapper/MapperFeatures.java

@@ -9,7 +9,6 @@
 
 package org.elasticsearch.index.mapper;
 
-import org.elasticsearch.common.util.set.Sets;
 import org.elasticsearch.features.FeatureSpecification;
 import org.elasticsearch.features.NodeFeature;
 import org.elasticsearch.index.IndexSettings;
@@ -29,7 +28,7 @@ public class MapperFeatures implements FeatureSpecification {
 
     @Override
     public Set<NodeFeature> getFeatures() {
-        Set<NodeFeature> features = Set.of(
+        return Set.of(
             BWC_WORKAROUND_9_0,
             IgnoredSourceFieldMapper.TRACK_IGNORED_SOURCE,
             PassThroughObjectMapper.PASS_THROUGH_PRIORITY,
@@ -55,11 +54,6 @@ public Set<NodeFeature> getFeatures() {
             TimeSeriesRoutingHashFieldMapper.TS_ROUTING_HASH_FIELD_PARSES_BYTES_REF,
             FlattenedFieldMapper.IGNORE_ABOVE_WITH_ARRAYS_SUPPORT
         );
-        // BBQ is currently behind a feature flag for testing
-        if (DenseVectorFieldMapper.BBQ_FEATURE_FLAG.isEnabled()) {
-            return Sets.union(features, Set.of(DenseVectorFieldMapper.BBQ_FORMAT));
-        }
-        return features;
     }
 
     @Override

server/src/main/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapper.java

@@ -109,7 +109,6 @@ public static boolean isNotUnitVector(float magnitude) {
 
     public static final NodeFeature INT4_QUANTIZATION = new NodeFeature("mapper.vectors.int4_quantization");
     public static final NodeFeature BIT_VECTORS = new NodeFeature("mapper.vectors.bit_vectors");
-    public static final NodeFeature BBQ_FORMAT = new NodeFeature("mapper.vectors.bbq");
     public static final FeatureFlag BBQ_FEATURE_FLAG = new FeatureFlag("bbq_index_format");
 
     public static final IndexVersion MAGNITUDE_STORED_INDEX_VERSION = IndexVersions.V_7_5_0;

server/src/main/java/org/elasticsearch/rest/action/search/SearchCapabilities.java

@@ -9,8 +9,11 @@
 
 package org.elasticsearch.rest.action.search;
 
+import java.util.HashSet;
 import java.util.Set;
 
+import static org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapper.BBQ_FEATURE_FLAG;
+
 /**
  * A {@link Set} of "capabilities" supported by the {@link RestSearchAction}.
  */
@@ -22,9 +25,16 @@ private SearchCapabilities() {}
     private static final String RANGE_REGEX_INTERVAL_QUERY_CAPABILITY = "range_regexp_interval_queries";
     /** Support synthetic source with `bit` type in `dense_vector` field when `index` is set to `false`. */
     private static final String BIT_DENSE_VECTOR_SYNTHETIC_SOURCE_CAPABILITY = "bit_dense_vector_synthetic_source";
+    private static final String BBQ_INDICES = "bbq_indices";
 
-    public static final Set<String> CAPABILITIES = Set.of(
-        RANGE_REGEX_INTERVAL_QUERY_CAPABILITY,
-        BIT_DENSE_VECTOR_SYNTHETIC_SOURCE_CAPABILITY
-    );
+    public static final Set<String> CAPABILITIES;
+    static {
+        HashSet<String> capabilities = new HashSet<>();
+        capabilities.add(RANGE_REGEX_INTERVAL_QUERY_CAPABILITY);
+        capabilities.add(BIT_DENSE_VECTOR_SYNTHETIC_SOURCE_CAPABILITY);
+        if (BBQ_FEATURE_FLAG.isEnabled()) {
+            capabilities.add(BBQ_INDICES);
+        }
+        CAPABILITIES = Set.copyOf(capabilities);
+    }
 }