Remove index.mapper.dynamic setting (#113000)

This setting had been removed in the past, it was reintroudced for bw comp with 7.x with #109341. It can now be removed from main as it no longer supports indices created with 7.x

Author: javanna

qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/UpgradeWithOldIndexSettingsIT.java

@@ -23,8 +23,6 @@
 import java.util.Map;
 
 import static org.elasticsearch.rest.action.search.RestSearchAction.TOTAL_HITS_AS_INT_PARAM;
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 
 public class UpgradeWithOldIndexSettingsIT extends AbstractRollingUpgradeTestCase {
@@ -105,39 +103,6 @@ public void testOldIndexSettings() throws Exception {
         }
     }
 
-    public void testMapperDynamicIndexSetting() throws IOException {
-        assumeTrue(
-            "Setting deprecated in 6.x, but was disallowed/removed incorrectly in some 7.x versions and can only be set safely in 7.17.22. "
-                + "Setting can't be used in 8.x ",
-            getOldClusterTestVersion().before("8.0.0") && getOldClusterTestVersion().after("7.17.21")
-        );
-        String indexName = "my-index";
-        if (isOldCluster()) {
-            createIndex(indexName);
-            Request request = new Request("PUT", "/" + indexName + "/_settings");
-            request.setJsonEntity(org.elasticsearch.common.Strings.toString(Settings.builder().put("index.mapper.dynamic", true).build()));
-            request.setOptions(
-                expectWarnings(
-                    "[index.mapper.dynamic] setting was deprecated in Elasticsearch and will be removed in a future release! "
-                        + "See the breaking changes documentation for the next major version."
-                )
-            );
-            assertOK(client().performRequest(request));
-        } else {
-            if (isUpgradedCluster()) {
-                var indexSettings = getIndexSettings(indexName);
-                assertThat(XContentMapValues.extractValue(indexName + ".settings.index.mapper.dynamic", indexSettings), equalTo("true"));
-                ensureGreen(indexName);
-                // New indices can never define the index.mapper.dynamic setting.
-                Exception e = expectThrows(
-                    ResponseException.class,
-                    () -> createIndex("my-index2", Settings.builder().put("index.mapper.dynamic", true).build())
-                );
-                assertThat(e.getMessage(), containsString("unknown setting [index.mapper.dynamic]"));
-            }
-        }
-    }
-
     private void assertCount(String index, int countAtLeast) throws IOException {
         Request searchTestIndexRequest = new Request("POST", "/" + index + "/_search");
         searchTestIndexRequest.addParameter(TOTAL_HITS_AS_INT_PARAM, "true");

qa/rolling-upgrade/src/javaRestTest/java/org/elasticsearch/upgrades/UpgradeWithOldIndexSettingsIT.java

@@ -161,7 +161,6 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
         MapperService.INDEX_MAPPING_DEPTH_LIMIT_SETTING,
         MapperService.INDEX_MAPPING_DIMENSION_FIELDS_LIMIT_SETTING,
         MapperService.INDEX_MAPPING_FIELD_NAME_LENGTH_LIMIT_SETTING,
-        MapperService.INDEX_MAPPER_DYNAMIC_SETTING,
         BitsetFilterCache.INDEX_LOAD_RANDOM_ACCESS_FILTERS_EAGERLY_SETTING,
         IndexModule.INDEX_STORE_TYPE_SETTING,
         IndexModule.INDEX_STORE_PRE_LOAD_SETTING,

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

@@ -22,7 +22,6 @@
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.core.Nullable;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.index.AbstractIndexComponent;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
@@ -149,19 +148,6 @@ public boolean isAutoUpdate() {
         Property.Dynamic,
         Property.IndexScope
     );
-    /**
-     * Legacy index setting, kept for 7.x BWC compatibility. This setting has no effect in 8.x. Do not use.
-     * TODO: Remove in 9.0
-     */
-    @Deprecated
-    @UpdateForV9
-    public static final Setting<Boolean> INDEX_MAPPER_DYNAMIC_SETTING = Setting.boolSetting(
-        "index.mapper.dynamic",
-        true,
-        Property.Dynamic,
-        Property.IndexScope,
-        Property.IndexSettingDeprecatedInV7AndRemovedInV8
-    );
 
     private final IndexAnalyzers indexAnalyzers;
     private final MappingParser mappingParser;