[8.19] refactor(semantic_text): fail early in pre-8.11 indices (#133080)

docs/changelog/133080.yaml

@@ -0,0 +1,5 @@
+pr: 133080
+summary: "Disallow creating `semantic_text` fields in indices created prior to 8.11.0"
+area: Relevance
+type: bug
+issues: []

server/src/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java

@@ -64,6 +64,7 @@
 
 import static org.apache.lucene.codecs.lucene99.Lucene99HnswVectorsFormat.DEFAULT_BEAM_WIDTH;
 import static org.apache.lucene.codecs.lucene99.Lucene99HnswVectorsFormat.DEFAULT_MAX_CONN;
+import static org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapper.INDEXED_BY_DEFAULT_INDEX_VERSION;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
@@ -100,7 +101,7 @@ private void indexMapping(XContentBuilder b, IndexVersion indexVersion) throws I
         if (elementType != ElementType.FLOAT) {
             b.field("element_type", elementType.toString());
         }
-        if (indexVersion.onOrAfter(DenseVectorFieldMapper.INDEXED_BY_DEFAULT_INDEX_VERSION) || indexed) {
+        if (indexVersion.onOrAfter(INDEXED_BY_DEFAULT_INDEX_VERSION) || indexed) {
             // Serialize if it's new index version, or it was not the default for previous indices
             b.field("index", indexed);
         }

test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java

@@ -517,7 +517,7 @@ public final void testMeta() throws IOException {
         );
     }
 
-    public final void testDeprecatedBoostWarning() throws IOException {
+    public void testDeprecatedBoostWarning() throws IOException {
         try {
             createMapperService(DEPRECATED_BOOST_INDEX_VERSION, fieldMapping(b -> {
                 minimalMapping(b, DEPRECATED_BOOST_INDEX_VERSION);

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

@@ -98,6 +98,7 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 
+import static org.elasticsearch.index.IndexVersions.NEW_SPARSE_VECTOR;
 import static org.elasticsearch.index.IndexVersions.SEMANTIC_TEXT_DEFAULTS_TO_BBQ_BACKPORT_8_X;
 import static org.elasticsearch.inference.TaskType.SPARSE_EMBEDDING;
 import static org.elasticsearch.inference.TaskType.TEXT_EMBEDDING;
@@ -122,6 +123,7 @@
  */
 public class SemanticTextFieldMapper extends FieldMapper implements InferenceFieldMapper {
     private static final Logger logger = LogManager.getLogger(SemanticTextFieldMapper.class);
+    public static final String UNSUPPORTED_INDEX_MESSAGE = "[semantic_text] is available on indices created with 8.11 or higher.";
     public static final NodeFeature SEMANTIC_TEXT_SEARCH_INFERENCE_ID = new NodeFeature("semantic_text.search_inference_id", true);
     public static final NodeFeature SEMANTIC_TEXT_DEFAULT_ELSER_2 = new NodeFeature("semantic_text.default_elser_2", true);
     public static final NodeFeature SEMANTIC_TEXT_IN_OBJECT_FIELD_FIX = new NodeFeature("semantic_text.in_object_field_fix");
@@ -156,6 +158,9 @@ public static final TypeParser parser(Supplier<ModelRegistry> modelRegistry) {
 
     public static BiConsumer<String, MappingParserContext> validateParserContext(String type) {
         return (n, c) -> {
+            if (c.getIndexSettings().getIndexVersionCreated().before(NEW_SPARSE_VECTOR)) {
+                throw new UnsupportedOperationException(UNSUPPORTED_INDEX_MESSAGE);
+            }
             if (InferenceMetadataFieldsMapper.isEnabled(c.getIndexSettings().getSettings()) == false) {
                 notInMultiFields(type).accept(n, c);
             }

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

@@ -107,9 +107,11 @@
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldMapper.DEFAULT_ELSER_2_INFERENCE_ID;
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldMapper.DEFAULT_RESCORE_OVERSAMPLE;
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldMapper.INDEX_OPTIONS_FIELD;
+import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldMapper.UNSUPPORTED_INDEX_MESSAGE;
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldTests.generateRandomChunkingSettings;
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldTests.generateRandomChunkingSettingsOtherThan;
 import static org.elasticsearch.xpack.inference.mapper.SemanticTextFieldTests.randomSemanticText;
+import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
@@ -400,6 +402,57 @@ public void testInvalidTaskTypes() {
         }
     }
 
+    @Override
+    protected IndexVersion boostNotAllowedIndexVersion() {
+        return IndexVersions.NEW_SPARSE_VECTOR;
+    }
+
+    public void testOldIndexSemanticTextDenseVectorRaisesError() throws IOException {
+        final String fieldName = "field";
+        final XContentBuilder fieldMapping = fieldMapping(b -> {
+            b.field("type", "semantic_text");
+            b.field(INFERENCE_ID_FIELD, "test_inference_id");
+            b.startObject("model_settings");
+            b.field("task_type", "text_embedding");
+            b.field("dimensions", 384);
+            b.field("similarity", "cosine");
+            b.field("element_type", "float");
+            b.endObject();
+        });
+        assertOldIndexUnsupported(fieldMapping);
+    }
+
+    public void testOldIndexSemanticTextMinimalMappingRaisesError() throws IOException {
+        final XContentBuilder fieldMapping = fieldMapping(this::minimalMapping);
+        assertOldIndexUnsupported(fieldMapping);
+    }
+
+    public void testOldIndexSemanticTextSparseVersionRaisesError() throws IOException {
+        final XContentBuilder fieldMapping = fieldMapping(b -> {
+            b.field("type", "semantic_text");
+            b.field("inference_id", "another_inference_id");
+            b.startObject("model_settings");
+            b.field("task_type", "sparse_embedding");
+            b.endObject();
+        });
+        assertOldIndexUnsupported(fieldMapping);
+    }
+
+    private void assertOldIndexUnsupported(XContentBuilder fieldMapping) {
+
+        MapperParsingException exception = assertThrows(
+            MapperParsingException.class,
+            () -> createMapperService(
+                fieldMapping,
+                true,
+                IndexVersions.V_8_0_0,
+                IndexVersionUtils.getPreviousVersion(IndexVersions.NEW_SPARSE_VECTOR)
+            )
+        );
+        assertTrue(exception.getMessage().contains(UNSUPPORTED_INDEX_MESSAGE));
+        assertTrue(exception.getRootCause() instanceof UnsupportedOperationException);
+    }
+
     public void testMultiFieldsSupport() throws IOException {
         if (useLegacyFormat) {
             Exception e = expectThrows(MapperParsingException.class, () -> createMapperService(fieldMapping(b -> {
@@ -1364,6 +1417,34 @@ public void testSpecifiedDenseVectorIndexOptions() throws IOException {
 
     }
 
+    /**
+     * Semantic text version error supersedes deprecated boost warning
+     * @throws IOException
+     */
+    @Override
+    public void testDeprecatedBoostWarning() throws IOException {
+        try {
+            createMapperService(DEPRECATED_BOOST_INDEX_VERSION, fieldMapping(b -> {
+                minimalMapping(b, DEPRECATED_BOOST_INDEX_VERSION);
+                b.field("boost", 2.0);
+            }));
+            String[] warnings = Strings.concatStringArrays(
+                getParseMinimalWarnings(DEPRECATED_BOOST_INDEX_VERSION),
+                new String[] { "Parameter [boost] on field [field] is deprecated and has no effect" }
+            );
+            assertWarnings(warnings);
+        } catch (MapperParsingException e) {
+            assertThat(
+                e.getMessage(),
+                anyOf(
+                    containsString(UNSUPPORTED_INDEX_MESSAGE),
+                    containsString("Unknown parameter [boost]"),
+                    containsString("[boost : 2.0]")
+                )
+            );
+        }
+    }
+
     public static SemanticTextIndexOptions randomSemanticTextIndexOptions() {
         TaskType taskType = randomFrom(TaskType.SPARSE_EMBEDDING, TaskType.TEXT_EMBEDDING);
         return randomSemanticTextIndexOptions(taskType);