[WIP] increase mapping field meta char limit

docs/reference/elasticsearch/mapping-reference/mapping-field-meta.md

@@ -24,7 +24,8 @@ PUT my-index-000001
 ```
 
 ::::{note}
-Field metadata enforces at most 5 entries, that keys have a length that is less than or equal to 20, and that values are strings whose length is less than or equal to 50.
+Field metadata enforces at most 5 entries, that keys have a length that is less than or equal to 20, and that values are strings whose length is less than or equal to 500.
+The value limit is configurable, with the index setting: `index.mapping.meta.length_limit`.
 ::::
 
 

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

@@ -204,6 +204,7 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
                 IndexSettings.INDEX_MAPPER_SOURCE_MODE_SETTING,
                 IndexSettings.RECOVERY_USE_SYNTHETIC_SOURCE_SETTING,
                 InferenceMetadataFieldsMapper.USE_LEGACY_SEMANTIC_TEXT_FORMAT,
+                IndexSettings.INDEX_MAPPING_META_LENGTH_LIMIT_SETTING,
 
                 // validate that built-in similarities don't get redefined
                 Setting.groupSetting("index.similarity.", (s) -> {

server/src/main/java/org/elasticsearch/index/IndexSettings.java

@@ -856,6 +856,14 @@ private static String getIgnoreAboveDefaultValue(final Settings settings) {
         Property.ServerlessPublic
     );
 
+    public static final Setting<Integer> INDEX_MAPPING_META_LENGTH_LIMIT_SETTING = Setting.intSetting(
+        "index.mapping.meta.length_limit",
+        500,
+        0,
+        Property.Dynamic,
+        Property.IndexScope
+    );
+
     private final Index index;
     private final IndexVersion version;
     private final Logger logger;

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

@@ -1298,7 +1298,7 @@ public static Parameter<Map<String, String>> metaParam() {
                 "meta",
                 true,
                 Map::of,
-                (n, c, o) -> TypeParsers.parseMeta(n, o),
+                (n, c, o) -> TypeParsers.parseMeta(n, o, c),
                 m -> m.fieldType().meta(),
                 XContentBuilder::stringStringMap,
                 Objects::toString

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

@@ -24,14 +24,15 @@
 
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.isArray;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeStringValue;
+import static org.elasticsearch.index.IndexSettings.INDEX_MAPPING_META_LENGTH_LIMIT_SETTING;
 
 public class TypeParsers {
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(TypeParsers.class);
 
     /**
      * Parse the {@code meta} key of the mapping.
      */
-    public static Map<String, String> parseMeta(String name, Object metaObject) {
+    public static Map<String, String> parseMeta(String name, Object metaObject, MappingParserContext parserContext) {
         if (metaObject instanceof Map == false) {
             throw new MapperParsingException(
                 "[meta] must be an object, got " + metaObject.getClass().getSimpleName() + "[" + metaObject + "] for field [" + name + "]"
@@ -52,11 +53,18 @@ public static Map<String, String> parseMeta(String name, Object metaObject) {
                 );
             }
         }
+        int metaValueLengthLimit = INDEX_MAPPING_META_LENGTH_LIMIT_SETTING.get(parserContext.getIndexSettings().getSettings());
         for (Object value : meta.values()) {
             if (value instanceof String sValue) {
-                if (sValue.codePointCount(0, sValue.length()) > 50) {
+                if (sValue.codePointCount(0, sValue.length()) > metaValueLengthLimit) {
                     throw new MapperParsingException(
-                        "[meta] values can't be longer than 50 chars, but got [" + value + "] for field [" + name + "]"
+                        "[meta] values can't be longer than "
+                            + metaValueLengthLimit
+                            + " chars, but got ["
+                            + value
+                            + "] for field ["
+                            + name
+                            + "]"
                     );
                 }
             } else if (value == null) {

server/src/test/java/org/elasticsearch/index/mapper/TypeParsersTests.java

@@ -35,6 +35,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
+import static org.elasticsearch.index.IndexSettings.INDEX_MAPPING_META_LENGTH_LIMIT_SETTING;
 import static org.elasticsearch.index.analysis.AnalysisRegistry.DEFAULT_ANALYZER_NAME;
 import static org.elasticsearch.index.analysis.AnalysisRegistry.DEFAULT_SEARCH_ANALYZER_NAME;
 import static org.elasticsearch.index.analysis.AnalysisRegistry.DEFAULT_SEARCH_QUOTED_ANALYZER_NAME;
@@ -52,48 +53,32 @@ private static Map<String, NamedAnalyzer> defaultAnalyzers() {
         return analyzers;
     }
 
-    public void testMultiFieldWithinMultiField() throws IOException {
-
-        XContentBuilder mapping = XContentFactory.jsonBuilder()
-            .startObject()
-            .field("type", "keyword")
-            .startObject("fields")
-            .startObject("sub-field")
-            .field("type", "keyword")
-            .startObject("fields")
-            .startObject("sub-sub-field")
-            .field("type", "keyword")
-            .endObject()
-            .endObject()
-            .endObject()
-            .endObject()
-            .endObject();
+    private Settings buildSettings() {
+        return Settings.builder()
+            .put(IndexMetadata.SETTING_VERSION_CREATED, IndexVersion.current())
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+            .build();
+    }
 
+    private MappingParserContext createParserContext(Settings settings) {
         Mapper.TypeParser typeParser = KeywordFieldMapper.PARSER;
 
         MapperService mapperService = mock(MapperService.class);
         IndexAnalyzers indexAnalyzers = IndexAnalyzers.of(defaultAnalyzers());
         when(mapperService.getIndexAnalyzers()).thenReturn(indexAnalyzers);
 
-        Settings settings = Settings.builder()
-            .put(IndexMetadata.SETTING_VERSION_CREATED, IndexVersion.current())
-            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
-            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
-            .build();
         IndexMetadata metadata = IndexMetadata.builder("test").settings(settings).build();
         IndexSettings indexSettings = new IndexSettings(metadata, Settings.EMPTY);
         when(mapperService.getIndexSettings()).thenReturn(indexSettings);
 
-        // For indices created in 8.0 or later, we should throw an error.
-        Map<String, Object> fieldNodeCopy = XContentHelper.convertToMap(BytesReference.bytes(mapping), true, mapping.contentType()).v2();
-
         IndexVersion version = IndexVersionUtils.randomVersionBetween(random(), IndexVersions.V_8_0_0, IndexVersion.current());
         TransportVersion transportVersion = TransportVersionUtils.randomVersionBetween(
             random(),
             TransportVersions.V_8_0_0,
             TransportVersion.current()
         );
-        MappingParserContext context = new MappingParserContext(
+        return new MappingParserContext(
             null,
             type -> typeParser,
             type -> null,
@@ -108,6 +93,29 @@ public void testMultiFieldWithinMultiField() throws IOException {
                 throw new UnsupportedOperationException();
             }
         );
+    }
+
+    public void testMultiFieldWithinMultiField() throws IOException {
+
+        XContentBuilder mapping = XContentFactory.jsonBuilder()
+            .startObject()
+            .field("type", "keyword")
+            .startObject("fields")
+            .startObject("sub-field")
+            .field("type", "keyword")
+            .startObject("fields")
+            .startObject("sub-sub-field")
+            .field("type", "keyword")
+            .endObject()
+            .endObject()
+            .endObject()
+            .endObject()
+            .endObject();
+
+        // For indices created in 8.0 or later, we should throw an error.
+        Map<String, Object> fieldNodeCopy = XContentHelper.convertToMap(BytesReference.bytes(mapping), true, mapping.contentType()).v2();
+
+        MappingParserContext context = createParserContext(buildSettings());
 
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> {
             TextFieldMapper.PARSER.parse("textField", fieldNodeCopy, context);
@@ -122,49 +130,80 @@ public void testMultiFieldWithinMultiField() throws IOException {
     }
 
     public void testParseMeta() {
+        MappingParserContext parserContext = createParserContext(buildSettings());
+
         {
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", 3));
+            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", 3, parserContext));
             assertEquals("[meta] must be an object, got Integer[3] for field [foo]", e.getMessage());
         }
 
         {
             MapperParsingException e = expectThrows(
                 MapperParsingException.class,
-                () -> TypeParsers.parseMeta("foo", Map.of("veryloooooooooooongkey", 3L))
+                () -> TypeParsers.parseMeta("foo", Map.of("veryloooooooooooongkey", 3L), parserContext)
             );
             assertEquals("[meta] keys can't be longer than 20 chars, but got [veryloooooooooooongkey] for field [foo]", e.getMessage());
         }
 
         {
             Map<String, Object> mapping = Map.of("foo1", 3L, "foo2", 4L, "foo3", 5L, "foo4", 6L, "foo5", 7L, "foo6", 8L);
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", mapping));
+            MapperParsingException e = expectThrows(
+                MapperParsingException.class,
+                () -> TypeParsers.parseMeta("foo", mapping, parserContext)
+            );
             assertEquals("[meta] can't have more than 5 entries, but got 6 on field [foo]", e.getMessage());
         }
 
         {
             Map<String, Object> mapping = Map.of("foo", Map.of("bar", "baz"));
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", mapping));
+            MapperParsingException e = expectThrows(
+                MapperParsingException.class,
+                () -> TypeParsers.parseMeta("foo", mapping, parserContext)
+            );
             assertEquals("[meta] values can only be strings, but got Map1[{bar=baz}] for field [foo]", e.getMessage());
         }
 
         {
             Map<String, Object> mapping = Map.of("bar", "baz", "foo", 3);
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", mapping));
+            MapperParsingException e = expectThrows(
+                MapperParsingException.class,
+                () -> TypeParsers.parseMeta("foo", mapping, parserContext)
+            );
             assertEquals("[meta] values can only be strings, but got Integer[3] for field [foo]", e.getMessage());
         }
 
         {
             Map<String, String> meta = new HashMap<>();
             meta.put("foo", null);
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", meta));
+            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", meta, parserContext));
             assertEquals("[meta] values can't be null (field [foo])", e.getMessage());
         }
 
         {
-            String longString = IntStream.range(0, 51).mapToObj(Integer::toString).collect(Collectors.joining());
+            String longString = IntStream.range(0, 501).mapToObj(Integer::toString).collect(Collectors.joining());
             Map<String, Object> mapping = Map.of("foo", longString);
-            MapperParsingException e = expectThrows(MapperParsingException.class, () -> TypeParsers.parseMeta("foo", mapping));
-            assertThat(e.getMessage(), Matchers.startsWith("[meta] values can't be longer than 50 chars"));
+            MapperParsingException e = expectThrows(
+                MapperParsingException.class,
+                () -> TypeParsers.parseMeta("foo", mapping, parserContext)
+            );
+            assertThat(e.getMessage(), Matchers.startsWith("[meta] values can't be longer than 500 chars"));
+        }
+
+        {
+            Settings otherSettings = Settings.builder()
+                .put(IndexMetadata.SETTING_VERSION_CREATED, IndexVersion.current())
+                .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1)
+                .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+                .put(INDEX_MAPPING_META_LENGTH_LIMIT_SETTING.getKey(), 300)
+                .build();
+            MappingParserContext otherParserContext = createParserContext(otherSettings);
+            String longString = IntStream.range(0, 301).mapToObj(Integer::toString).collect(Collectors.joining());
+            Map<String, Object> mapping = Map.of("foo", longString);
+            MapperParsingException e = expectThrows(
+                MapperParsingException.class,
+                () -> TypeParsers.parseMeta("foo", mapping, otherParserContext)
+            );
+            assertThat(e.getMessage(), Matchers.startsWith("[meta] values can't be longer than 300 chars"));
         }
     }
 }

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowAction.java

@@ -496,6 +496,7 @@ static String[] extractLeaderShardHistoryUUIDs(Map<String, String> ccrIndexMetad
         IndexSettings.INDEX_FLUSH_AFTER_MERGE_THRESHOLD_SIZE_SETTING,
         IndexSettings.INDEX_GC_DELETES_SETTING,
         IndexSettings.MAX_REFRESH_LISTENERS_PER_SHARD,
+        IndexSettings.INDEX_MAPPING_META_LENGTH_LIMIT_SETTING,
         IndicesRequestCache.INDEX_CACHE_REQUEST_ENABLED_SETTING,
         BitsetFilterCache.INDEX_LOAD_RANDOM_ACCESS_FILTERS_EAGERLY_SETTING,
         SearchSlowLog.INDEX_SEARCH_SLOWLOG_THRESHOLD_FETCH_DEBUG_SETTING,