Always Enable Default ELSER Endpoint For Semantic Text

docs/changelog/116841.yaml

@@ -0,0 +1,5 @@
+pr: 116841
+summary: Use ELSER By Default For Semantic Text
+area: Mapping
+type: enhancement
+issues: []

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferenceFeatures.java

@@ -14,7 +14,6 @@
 import org.elasticsearch.xpack.inference.rank.random.RandomRankRetrieverBuilder;
 import org.elasticsearch.xpack.inference.rank.textsimilarity.TextSimilarityRankRetrieverBuilder;
 
-import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -24,16 +23,14 @@ public class InferenceFeatures implements FeatureSpecification {
 
     @Override
     public Set<NodeFeature> getFeatures() {
-        var features = new HashSet<NodeFeature>();
-        features.add(TextSimilarityRankRetrieverBuilder.TEXT_SIMILARITY_RERANKER_RETRIEVER_SUPPORTED);
-        features.add(RandomRankRetrieverBuilder.RANDOM_RERANKER_RETRIEVER_SUPPORTED);
-        features.add(SemanticTextFieldMapper.SEMANTIC_TEXT_SEARCH_INFERENCE_ID);
-        features.add(SemanticQueryBuilder.SEMANTIC_TEXT_INNER_HITS);
-        features.add(TextSimilarityRankRetrieverBuilder.TEXT_SIMILARITY_RERANKER_COMPOSITION_SUPPORTED);
-        if (DefaultElserFeatureFlag.isEnabled()) {
-            features.add(SemanticTextFieldMapper.SEMANTIC_TEXT_DEFAULT_ELSER_2);
-        }
-        return Set.copyOf(features);
+        return Set.of(
+            TextSimilarityRankRetrieverBuilder.TEXT_SIMILARITY_RERANKER_RETRIEVER_SUPPORTED,
+            RandomRankRetrieverBuilder.RANDOM_RERANKER_RETRIEVER_SUPPORTED,
+            SemanticTextFieldMapper.SEMANTIC_TEXT_SEARCH_INFERENCE_ID,
+            SemanticQueryBuilder.SEMANTIC_TEXT_INNER_HITS,
+            SemanticTextFieldMapper.SEMANTIC_TEXT_DEFAULT_ELSER_2,
+            TextSimilarityRankRetrieverBuilder.TEXT_SIMILARITY_RERANKER_COMPOSITION_SUPPORTED
+        );
     }
 
     @Override

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/mapper/SemanticTextFieldMapper.java

@@ -57,7 +57,6 @@
 import org.elasticsearch.xcontent.XContentParserConfiguration;
 import org.elasticsearch.xpack.core.ml.inference.results.MlTextEmbeddingResults;
 import org.elasticsearch.xpack.core.ml.inference.results.TextExpansionResults;
-import org.elasticsearch.xpack.inference.DefaultElserFeatureFlag;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -111,16 +110,12 @@ public static class Builder extends FieldMapper.Builder {
             INFERENCE_ID_FIELD,
             false,
             mapper -> ((SemanticTextFieldType) mapper.fieldType()).inferenceId,
-            DefaultElserFeatureFlag.isEnabled() ? DEFAULT_ELSER_2_INFERENCE_ID : null
+            DEFAULT_ELSER_2_INFERENCE_ID
         ).addValidator(v -> {
             if (Strings.isEmpty(v)) {
-                // If the default ELSER feature flag is enabled, the only way we get here is if the user explicitly sets the param to an
-                // empty value. However, if the feature flag is disabled, we can get here if the user didn't set the param.
-                // Adjust the error message appropriately.
-                String message = DefaultElserFeatureFlag.isEnabled()
-                    ? "[" + INFERENCE_ID_FIELD + "] on mapper [" + leafName() + "] of type [" + CONTENT_TYPE + "] must not be empty"
-                    : "[" + INFERENCE_ID_FIELD + "] on mapper [" + leafName() + "] of type [" + CONTENT_TYPE + "] must be specified";
-                throw new IllegalArgumentException(message);
+                throw new IllegalArgumentException(
+                    "[" + INFERENCE_ID_FIELD + "] on mapper [" + leafName() + "] of type [" + CONTENT_TYPE + "] must not be empty"
+                );
             }
         });
 

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/mapper/SemanticTextFieldMapperTests.java

@@ -61,7 +61,6 @@
 import org.elasticsearch.xcontent.XContentParser;
 import org.elasticsearch.xcontent.XContentType;
 import org.elasticsearch.xcontent.json.JsonXContent;
-import org.elasticsearch.xpack.inference.DefaultElserFeatureFlag;
 import org.elasticsearch.xpack.inference.InferencePlugin;
 import org.elasticsearch.xpack.inference.model.TestModel;
 import org.junit.AssumptionViolatedException;
@@ -103,9 +102,6 @@ protected Collection<? extends Plugin> getPlugins() {
     @Override
     protected void minimalMapping(XContentBuilder b) throws IOException {
         b.field("type", "semantic_text");
-        if (DefaultElserFeatureFlag.isEnabled() == false) {
-            b.field("inference_id", "test_model");
-        }
     }
 
     @Override
@@ -175,9 +171,7 @@ public void testDefaults() throws Exception {
         DocumentMapper mapper = mapperService.documentMapper();
         assertEquals(Strings.toString(fieldMapping), mapper.mappingSource().toString());
         assertSemanticTextField(mapperService, fieldName, false);
-        if (DefaultElserFeatureFlag.isEnabled()) {
-            assertInferenceEndpoints(mapperService, fieldName, DEFAULT_ELSER_2_INFERENCE_ID, DEFAULT_ELSER_2_INFERENCE_ID);
-        }
+        assertInferenceEndpoints(mapperService, fieldName, DEFAULT_ELSER_2_INFERENCE_ID, DEFAULT_ELSER_2_INFERENCE_ID);
 
         ParsedDocument doc1 = mapper.parse(source(this::writeField));
         List<IndexableField> fields = doc1.rootDoc().getFields("field");
@@ -211,15 +205,13 @@ public void testSetInferenceEndpoints() throws IOException {
             assertSerialization.accept(fieldMapping, mapperService);
         }
         {
-            if (DefaultElserFeatureFlag.isEnabled()) {
-                final XContentBuilder fieldMapping = fieldMapping(
-                    b -> b.field("type", "semantic_text").field(SEARCH_INFERENCE_ID_FIELD, searchInferenceId)
-                );
-                final MapperService mapperService = createMapperService(fieldMapping);
-                assertSemanticTextField(mapperService, fieldName, false);
-                assertInferenceEndpoints(mapperService, fieldName, DEFAULT_ELSER_2_INFERENCE_ID, searchInferenceId);
-                assertSerialization.accept(fieldMapping, mapperService);
-            }
+            final XContentBuilder fieldMapping = fieldMapping(
+                b -> b.field("type", "semantic_text").field(SEARCH_INFERENCE_ID_FIELD, searchInferenceId)
+            );
+            final MapperService mapperService = createMapperService(fieldMapping);
+            assertSemanticTextField(mapperService, fieldName, false);
+            assertInferenceEndpoints(mapperService, fieldName, DEFAULT_ELSER_2_INFERENCE_ID, searchInferenceId);
+            assertSerialization.accept(fieldMapping, mapperService);
         }
         {
             final XContentBuilder fieldMapping = fieldMapping(
@@ -246,26 +238,18 @@ public void testInvalidInferenceEndpoints() {
             );
         }
         {
-            final String expectedMessage = DefaultElserFeatureFlag.isEnabled()
-                ? "[inference_id] on mapper [field] of type [semantic_text] must not be empty"
-                : "[inference_id] on mapper [field] of type [semantic_text] must be specified";
             Exception e = expectThrows(
                 MapperParsingException.class,
                 () -> createMapperService(fieldMapping(b -> b.field("type", "semantic_text").field(INFERENCE_ID_FIELD, "")))
             );
-            assertThat(e.getMessage(), containsString(expectedMessage));
+            assertThat(e.getMessage(), containsString("[inference_id] on mapper [field] of type [semantic_text] must not be empty"));
         }
         {
-            if (DefaultElserFeatureFlag.isEnabled()) {
-                Exception e = expectThrows(
-                    MapperParsingException.class,
-                    () -> createMapperService(fieldMapping(b -> b.field("type", "semantic_text").field(SEARCH_INFERENCE_ID_FIELD, "")))
-                );
-                assertThat(
-                    e.getMessage(),
-                    containsString("[search_inference_id] on mapper [field] of type [semantic_text] must not be empty")
-                );
-            }
+            Exception e = expectThrows(
+                MapperParsingException.class,
+                () -> createMapperService(fieldMapping(b -> b.field("type", "semantic_text").field(SEARCH_INFERENCE_ID_FIELD, "")))
+            );
+            assertThat(e.getMessage(), containsString("[search_inference_id] on mapper [field] of type [semantic_text] must not be empty"));
         }
     }
 

x-pack/plugin/inference/src/yamlRestTest/resources/rest-api-spec/test/inference/30_semantic_text_inference.yml

@@ -551,7 +551,7 @@ setup:
 ---
 "Calculates embeddings using the default ELSER 2 endpoint":
   - requires:
-      reason: "default ELSER 2 inference ID is behind a feature flag"
+      reason: "default ELSER 2 inference ID is enabled via a capability"
       test_runner_features: [capabilities]
       capabilities:
         - method: GET

x-pack/plugin/inference/src/yamlRestTest/resources/rest-api-spec/test/inference/40_semantic_text_query.yml

@@ -843,7 +843,7 @@ setup:
 ---
 "Query a field that uses the default ELSER 2 endpoint":
   - requires:
-      reason: "default ELSER 2 inference ID is behind a feature flag"
+      reason: "default ELSER 2 inference ID is enabled via a capability"
       test_runner_features: [capabilities]
       capabilities:
         - method: GET