Hide ImmutableOpenMap in Metadata public methods (#87124)

This commit converts the remaining methods in Metadata that return an
ImmutableOpenMap to return Map, thus hiding the fact that Metadata uses
ImmutableOpenMap internally.

relates #86239

server/src/internalClusterTest/java/org/elasticsearch/cluster/ClusterStateDiffIT.java

@@ -646,7 +646,7 @@ public class ClusterStateDiffIT extends ESIntegTestCase {
         return randomParts(metadata, "custom", new RandomPart<Metadata.Custom>() {
 
             @Override
-            public ImmutableOpenMap<String, Metadata.Custom> parts(Metadata metadata) {
+            public Map<String, Metadata.Custom> parts(Metadata metadata) {
                 return metadata.customs();
             }
 

server/src/main/java/org/elasticsearch/action/admin/indices/alias/TransportIndicesAliasesAction.java

@@ -29,7 +29,6 @@ import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.metadata.MetadataIndexAliasesService;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.index.Index;
@@ -44,6 +43,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
@@ -248,7 +248,7 @@ public class TransportIndicesAliasesAction extends AcknowledgedTransportMasterNo
         if (action.expandAliasesWildcards()) {
             // for DELETE we expand the aliases
             String[] concreteIndices = { concreteIndex };
-            ImmutableOpenMap<String, List<AliasMetadata>> aliasMetadata = metadata.findAliases(action.aliases(), concreteIndices);
+            Map<String, List<AliasMetadata>> aliasMetadata = metadata.findAliases(action.aliases(), concreteIndices);
             List<String> finalAliases = new ArrayList<>();
             for (List<AliasMetadata> aliases : aliasMetadata.values()) {
                 for (AliasMetadata aliasMeta : aliases) {

server/src/main/java/org/elasticsearch/action/admin/indices/alias/get/TransportGetAliasesAction.java

@@ -83,7 +83,7 @@ public class TransportGetAliasesAction extends TransportMasterNodeReadAction<Get
         // resolve all concrete indices upfront and warn/error later
         final String[] concreteIndices = indexNameExpressionResolver.concreteIndexNamesWithSystemIndexAccess(state, request);
         final SystemIndexAccessLevel systemIndexAccessLevel = indexNameExpressionResolver.getSystemIndexAccessLevel();
-        ImmutableOpenMap<String, List<AliasMetadata>> aliases = state.metadata().findAliases(request.aliases(), concreteIndices);
+        Map<String, List<AliasMetadata>> aliases = state.metadata().findAliases(request.aliases(), concreteIndices);
         listener.onResponse(
             new GetAliasesResponse(
                 postProcess(request, concreteIndices, aliases, state, systemIndexAccessLevel, threadPool.getThreadContext(), systemIndices),
@@ -98,7 +98,7 @@ public class TransportGetAliasesAction extends TransportMasterNodeReadAction<Get
     static ImmutableOpenMap<String, List<AliasMetadata>> postProcess(
         GetAliasesRequest request,
         String[] concreteIndices,
-        ImmutableOpenMap<String, List<AliasMetadata>> aliases,
+        Map<String, List<AliasMetadata>> aliases,
         ClusterState state,
         SystemIndexAccessLevel systemIndexAccessLevel,
         ThreadContext threadContext,

server/src/main/java/org/elasticsearch/action/admin/indices/get/TransportGetIndexAction.java

@@ -76,8 +76,8 @@ public class TransportGetIndexAction extends TransportClusterInfoAction<GetIndex
         final ClusterState state,
         final ActionListener<GetIndexResponse> listener
     ) {
-        ImmutableOpenMap<String, MappingMetadata> mappingsResult = ImmutableOpenMap.of();
-        ImmutableOpenMap<String, List<AliasMetadata>> aliasesResult = ImmutableOpenMap.of();
+        Map<String, MappingMetadata> mappingsResult = ImmutableOpenMap.of();
+        Map<String, List<AliasMetadata>> aliasesResult = Map.of();
         ImmutableOpenMap<String, Settings> settings = ImmutableOpenMap.of();
         ImmutableOpenMap<String, Settings> defaultSettings = ImmutableOpenMap.of();
         ImmutableOpenMap<String, String> dataStreams = ImmutableOpenMap.<String, String>builder()

server/src/main/java/org/elasticsearch/action/admin/indices/mapping/get/TransportGetMappingsAction.java

@@ -18,7 +18,6 @@ import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.MappingMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.service.ClusterService;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.tasks.CancellableTask;
@@ -26,6 +25,7 @@ import org.elasticsearch.tasks.Task;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
+import java.util.Map;
 import java.util.concurrent.CancellationException;
 
 public class TransportGetMappingsAction extends TransportClusterInfoAction<GetMappingsRequest, GetMappingsResponse> {
@@ -66,7 +66,7 @@ public class TransportGetMappingsAction extends TransportClusterInfoAction<GetMa
     ) {
         logger.trace("serving getMapping request based on version {}", state.version());
         final Metadata metadata = state.metadata();
-        final ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+        final Map<String, MappingMetadata> mappings = metadata.findMappings(
             concreteIndices,
             indicesService.getFieldFilter(),
             () -> checkCancellation(task)

server/src/main/java/org/elasticsearch/cluster/ClusterChangedEvent.java

@@ -13,7 +13,6 @@ import org.elasticsearch.cluster.metadata.IndexGraveyard.IndexGraveyardDiff;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.gateway.GatewayService;
 import org.elasticsearch.index.Index;
 
@@ -142,8 +141,8 @@ public class ClusterChangedEvent {
      */
     public Set<String> changedCustomMetadataSet() {
         Set<String> result = new HashSet<>();
-        ImmutableOpenMap<String, Metadata.Custom> currentCustoms = state.metadata().customs();
-        ImmutableOpenMap<String, Metadata.Custom> previousCustoms = previousState.metadata().customs();
+        Map<String, Metadata.Custom> currentCustoms = state.metadata().customs();
+        Map<String, Metadata.Custom> previousCustoms = previousState.metadata().customs();
         if (currentCustoms.equals(previousCustoms) == false) {
             for (Map.Entry<String, Metadata.Custom> currentCustomMetadata : currentCustoms.entrySet()) {
                 // new custom md added or existing custom md changed

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -450,7 +450,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
      * @return A map of index name to the list of aliases metadata. If a concrete index does not have matching
      * aliases then the result will <b>not</b> include the index's key.
      */
-    public ImmutableOpenMap<String, List<AliasMetadata>> findAllAliases(final String[] concreteIndices) {
+    public Map<String, List<AliasMetadata>> findAllAliases(final String[] concreteIndices) {
         return findAliases(Strings.EMPTY_ARRAY, concreteIndices);
     }
 
@@ -463,7 +463,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
      * @return A map of index name to the list of aliases metadata. If a concrete index does not have matching
      * aliases then the result will <b>not</b> include the index's key.
      */
-    public ImmutableOpenMap<String, List<AliasMetadata>> findAliases(final String[] aliases, final String[] concreteIndices) {
+    public Map<String, List<AliasMetadata>> findAliases(final String[] aliases, final String[] concreteIndices) {
         assert aliases != null;
         assert concreteIndices != null;
         if (concreteIndices.length == 0) {
@@ -521,7 +521,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
      *
      * @param onNextIndex a hook that gets notified for each index that's processed
      */
-    public ImmutableOpenMap<String, MappingMetadata> findMappings(
+    public Map<String, MappingMetadata> findMappings(
         String[] concreteIndices,
         Function<String, Predicate<String>> fieldFilter,
         Runnable onNextIndex
@@ -545,7 +545,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
     /**
      * Finds the parent data streams, if any, for the specified concrete indices.
      */
-    public ImmutableOpenMap<String, IndexAbstraction.DataStream> findDataStreams(String... concreteIndices) {
+    public Map<String, IndexAbstraction.DataStream> findDataStreams(String... concreteIndices) {
         assert concreteIndices != null;
         final ImmutableOpenMap.Builder<String, IndexAbstraction.DataStream> builder = ImmutableOpenMap.builder();
         final SortedMap<String, IndexAbstraction> lookup = getIndicesLookup();
@@ -934,7 +934,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
             .orElse(Collections.emptyMap());
     }
 
-    public ImmutableOpenMap<String, Custom> customs() {
+    public Map<String, Custom> customs() {
         return this.customs;
     }
 
@@ -1402,7 +1402,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
             return this;
         }
 
-        public Builder indices(ImmutableOpenMap<String, IndexMetadata> indices) {
+        public Builder indices(Map<String, IndexMetadata> indices) {
             for (var value : indices.values()) {
                 put(value, false);
             }
@@ -1484,7 +1484,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
             return this;
         }
 
-        public Builder templates(ImmutableOpenMap<String, IndexTemplateMetadata> templates) {
+        public Builder templates(Map<String, IndexTemplateMetadata> templates) {
             this.templates.putAllFromMap(templates);
             return this;
         }
@@ -1629,7 +1629,7 @@ public class Metadata extends AbstractCollection<IndexMetadata> implements Diffa
             return this;
         }
 
-        public Builder customs(ImmutableOpenMap<String, Custom> customs) {
+        public Builder customs(Map<String, Custom> customs) {
             customs.forEach((key, value) -> Objects.requireNonNull(value, key));
             this.customs.putAllFromMap(customs);
             return this;

server/src/test/java/org/elasticsearch/cluster/metadata/MetadataTests.java

@@ -93,7 +93,7 @@ public class MetadataTests extends ESTestCase {
 
         {
             GetAliasesRequest request = new GetAliasesRequest();
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), Strings.EMPTY_ARRAY);
+            Map<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), Strings.EMPTY_ARRAY);
             assertThat(aliases.size(), equalTo(0));
         }
         {
@@ -105,7 +105,7 @@ public class MetadataTests extends ESTestCase {
                 // replacing with empty aliases behaves as if aliases were unspecified at request building
                 request.replaceAliases(Strings.EMPTY_ARRAY);
             }
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
+            Map<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
             assertThat(aliases.size(), equalTo(1));
             List<AliasMetadata> aliasMetadataList = aliases.get("index");
             assertThat(aliasMetadataList.size(), equalTo(2));
@@ -114,7 +114,7 @@ public class MetadataTests extends ESTestCase {
         }
         {
             GetAliasesRequest request = new GetAliasesRequest("alias*");
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
+            Map<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
             assertThat(aliases.size(), equalTo(1));
             List<AliasMetadata> aliasMetadataList = aliases.get("index");
             assertThat(aliasMetadataList.size(), equalTo(2));
@@ -123,14 +123,14 @@ public class MetadataTests extends ESTestCase {
         }
         {
             GetAliasesRequest request = new GetAliasesRequest("alias1");
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
+            Map<String, List<AliasMetadata>> aliases = metadata.findAliases(request.aliases(), new String[] { "index" });
             assertThat(aliases.size(), equalTo(1));
             List<AliasMetadata> aliasMetadataList = aliases.get("index");
             assertThat(aliasMetadataList.size(), equalTo(1));
             assertThat(aliasMetadataList.get(0).alias(), equalTo("alias1"));
         }
         {
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAllAliases(new String[] { "index" });
+            Map<String, List<AliasMetadata>> aliases = metadata.findAllAliases(new String[] { "index" });
             assertThat(aliases.size(), equalTo(1));
             List<AliasMetadata> aliasMetadataList = aliases.get("index");
             assertThat(aliasMetadataList.size(), equalTo(2));
@@ -138,7 +138,7 @@ public class MetadataTests extends ESTestCase {
             assertThat(aliasMetadataList.get(1).alias(), equalTo("alias2"));
         }
         {
-            ImmutableOpenMap<String, List<AliasMetadata>> aliases = metadata.findAllAliases(Strings.EMPTY_ARRAY);
+            Map<String, List<AliasMetadata>> aliases = metadata.findAllAliases(Strings.EMPTY_ARRAY);
             assertThat(aliases.size(), equalTo(0));
         }
     }
@@ -169,7 +169,7 @@ public class MetadataTests extends ESTestCase {
         List<Index> allIndices = new ArrayList<>(result.indices);
         allIndices.addAll(result.backingIndices);
         String[] concreteIndices = allIndices.stream().map(Index::getName).toList().toArray(new String[] {});
-        ImmutableOpenMap<String, IndexAbstraction.DataStream> dataStreams = result.metadata.findDataStreams(concreteIndices);
+        Map<String, IndexAbstraction.DataStream> dataStreams = result.metadata.findDataStreams(concreteIndices);
         assertThat(dataStreams.size(), equalTo(numBackingIndices));
         for (Index backingIndex : result.backingIndices) {
             assertThat(dataStreams.containsKey(backingIndex.getName()), is(true));
@@ -656,7 +656,7 @@ public class MetadataTests extends ESTestCase {
 
         {
             AtomicInteger onNextIndexCalls = new AtomicInteger(0);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 Strings.EMPTY_ARRAY,
                 MapperPlugin.NOOP_FIELD_FILTER,
                 onNextIndexCalls::incrementAndGet
@@ -666,7 +666,7 @@ public class MetadataTests extends ESTestCase {
         }
         {
             AtomicInteger onNextIndexCalls = new AtomicInteger(0);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1" },
                 MapperPlugin.NOOP_FIELD_FILTER,
                 onNextIndexCalls::incrementAndGet
@@ -677,7 +677,7 @@ public class MetadataTests extends ESTestCase {
         }
         {
             AtomicInteger onNextIndexCalls = new AtomicInteger(0);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1", "index2" },
                 MapperPlugin.NOOP_FIELD_FILTER,
                 onNextIndexCalls::incrementAndGet
@@ -709,7 +709,7 @@ public class MetadataTests extends ESTestCase {
             .build();
 
         {
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1" },
                 MapperPlugin.NOOP_FIELD_FILTER,
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -718,7 +718,7 @@ public class MetadataTests extends ESTestCase {
             assertSame(originalMappingMetadata, mappingMetadata);
         }
         {
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1" },
                 index -> field -> randomBoolean(),
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -774,22 +774,18 @@ public class MetadataTests extends ESTestCase {
             .build();
 
         {
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
-                new String[] { "index1", "index2", "index3" },
-                index -> {
-                    if (index.equals("index1")) {
-                        return field -> field.startsWith("name.") == false
-                            && field.startsWith("properties.key.") == false
-                            && field.equals("age") == false
-                            && field.equals("address.location") == false;
-                    }
-                    if (index.equals("index2")) {
-                        return field -> false;
-                    }
-                    return MapperPlugin.NOOP_FIELD_PREDICATE;
-                },
-                Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
-            );
+            Map<String, MappingMetadata> mappings = metadata.findMappings(new String[] { "index1", "index2", "index3" }, index -> {
+                if (index.equals("index1")) {
+                    return field -> field.startsWith("name.") == false
+                        && field.startsWith("properties.key.") == false
+                        && field.equals("age") == false
+                        && field.equals("address.location") == false;
+                }
+                if (index.equals("index2")) {
+                    return field -> false;
+                }
+                return MapperPlugin.NOOP_FIELD_PREDICATE;
+            }, Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP);
 
             assertIndexMappingsNoFields(mappings, "index2");
             assertIndexMappingsNotFiltered(mappings, "index3");
@@ -836,7 +832,7 @@ public class MetadataTests extends ESTestCase {
         }
 
         {
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1", "index2", "index3" },
                 index -> field -> (index.equals("index3") && field.endsWith("keyword")),
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -872,7 +868,7 @@ public class MetadataTests extends ESTestCase {
         }
 
         {
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index1", "index2", "index3" },
                 index -> field -> (index.equals("index2")),
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -930,7 +926,7 @@ public class MetadataTests extends ESTestCase {
     }
 
     @SuppressWarnings("unchecked")
-    private static void assertIndexMappingsNoFields(ImmutableOpenMap<String, MappingMetadata> mappings, String index) {
+    private static void assertIndexMappingsNoFields(Map<String, MappingMetadata> mappings, String index) {
         MappingMetadata docMapping = mappings.get(index);
         assertNotNull(docMapping);
         Map<String, Object> sourceAsMap = docMapping.getSourceAsMap();
@@ -942,7 +938,7 @@ public class MetadataTests extends ESTestCase {
     }
 
     @SuppressWarnings("unchecked")
-    private static void assertIndexMappingsNotFiltered(ImmutableOpenMap<String, MappingMetadata> mappings, String index) {
+    private static void assertIndexMappingsNotFiltered(Map<String, MappingMetadata> mappings, String index) {
         MappingMetadata docMapping = mappings.get(index);
         assertNotNull(docMapping);
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/job/persistence/ElasticsearchMappings.java

@@ -19,7 +19,6 @@ import org.elasticsearch.cluster.metadata.IndexAbstraction;
 import org.elasticsearch.cluster.metadata.MappingMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.common.CheckedSupplier;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.plugins.MapperPlugin;
@@ -100,7 +99,7 @@ public class ElasticsearchMappings {
     static String[] mappingRequiresUpdate(ClusterState state, String[] concreteIndices, Version minVersion) {
         List<String> indicesToUpdate = new ArrayList<>();
 
-        ImmutableOpenMap<String, MappingMetadata> currentMapping = state.metadata()
+        Map<String, MappingMetadata> currentMapping = state.metadata()
             .findMappings(concreteIndices, MapperPlugin.NOOP_FIELD_FILTER, Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP);
 
         for (String index : concreteIndices) {

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/authz/accesscontrol/FieldSubsetReaderTests.java

@@ -57,7 +57,6 @@ import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.MappingMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.lucene.index.SequentialStoredFieldsLeafReader;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentHelper;
@@ -1078,7 +1077,7 @@ public class FieldSubsetReaderTests extends ESTestCase {
         {
             FieldPermissionsDefinition definition = new FieldPermissionsDefinition(new String[] { "*inner1" }, Strings.EMPTY_ARRAY);
             FieldPermissions fieldPermissions = new FieldPermissions(definition);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index" },
                 index -> fieldPermissions::grantsAccessTo,
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -1118,7 +1117,7 @@ public class FieldSubsetReaderTests extends ESTestCase {
         {
             FieldPermissionsDefinition definition = new FieldPermissionsDefinition(new String[] { "object*" }, Strings.EMPTY_ARRAY);
             FieldPermissions fieldPermissions = new FieldPermissions(definition);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index" },
                 index -> fieldPermissions::grantsAccessTo,
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -1157,7 +1156,7 @@ public class FieldSubsetReaderTests extends ESTestCase {
         {
             FieldPermissionsDefinition definition = new FieldPermissionsDefinition(new String[] { "object" }, Strings.EMPTY_ARRAY);
             FieldPermissions fieldPermissions = new FieldPermissions(definition);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index" },
                 index -> fieldPermissions::grantsAccessTo,
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP
@@ -1186,7 +1185,7 @@ public class FieldSubsetReaderTests extends ESTestCase {
         {
             FieldPermissionsDefinition definition = new FieldPermissionsDefinition(new String[] { "nested.inner2" }, Strings.EMPTY_ARRAY);
             FieldPermissions fieldPermissions = new FieldPermissions(definition);
-            ImmutableOpenMap<String, MappingMetadata> mappings = metadata.findMappings(
+            Map<String, MappingMetadata> mappings = metadata.findMappings(
                 new String[] { "index" },
                 index -> fieldPermissions::grantsAccessTo,
                 Metadata.ON_NEXT_INDEX_FIND_MAPPINGS_NOOP

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authz/IndicesAndAliasesResolver.java

@@ -19,7 +19,6 @@ import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.ClusterSettings;
 import org.elasticsearch.common.settings.Settings;
@@ -332,7 +331,7 @@ class IndicesAndAliasesResolver {
         } else {
             // the user is not authorized to put mappings for this index, but could have been
             // authorized for a write using an alias that triggered a dynamic mapping update
-            ImmutableOpenMap<String, List<AliasMetadata>> foundAliases = metadata.findAllAliases(new String[] { concreteIndexName });
+            Map<String, List<AliasMetadata>> foundAliases = metadata.findAllAliases(new String[] { concreteIndexName });
             List<AliasMetadata> aliasMetadata = foundAliases.get(concreteIndexName);
             if (aliasMetadata != null) {
                 Optional<String> foundAlias = aliasMetadata.stream()