Merge branch 'master' into enhancement/use_shard_bulk_for_single_ops

buildSrc/src/main/resources/checkstyle_suppressions.xml

@@ -349,7 +349,6 @@
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]fielddata[/\\]plain[/\\]ParentChildIndexFieldData.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]fielddata[/\\]plain[/\\]SortedNumericDVIndexFieldData.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]fielddata[/\\]plain[/\\]SortedSetDVOrdinalsIndexFieldData.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]get[/\\]GetResult.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]get[/\\]ShardGetService.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]mapper[/\\]DocumentFieldMappers.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]index[/\\]mapper[/\\]DocumentMapper.java" checks="LineLength" />

core/src/main/java/org/elasticsearch/ElasticsearchException.java

@@ -44,7 +44,7 @@ import java.util.stream.Collectors;
 
 import static java.util.Collections.unmodifiableMap;
 import static org.elasticsearch.cluster.metadata.IndexMetaData.INDEX_UUID_NA_VALUE;
-import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureFieldName;
+import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
 import static org.elasticsearch.common.xcontent.XContentParserUtils.throwUnknownField;
 
 /**
@@ -357,7 +357,8 @@ public class ElasticsearchException extends RuntimeException implements ToXConte
      * instances.
      */
     public static ElasticsearchException fromXContent(XContentParser parser) throws IOException {
-        XContentParser.Token token = ensureFieldName(parser.nextToken(), parser::getTokenLocation);
+        XContentParser.Token token = parser.nextToken();
+        ensureExpectedToken(XContentParser.Token.FIELD_NAME, token, parser::getTokenLocation);
 
         String type = null, reason = null, stack = null;
         ElasticsearchException cause = null;
@@ -786,7 +787,9 @@ public class ElasticsearchException extends RuntimeException implements ToXConte
         TASK_CANCELLED_EXCEPTION(org.elasticsearch.tasks.TaskCancelledException.class,
             org.elasticsearch.tasks.TaskCancelledException::new, 146, Version.V_5_1_1_UNRELEASED),
         SHARD_LOCK_OBTAIN_FAILED_EXCEPTION(org.elasticsearch.env.ShardLockObtainFailedException.class,
-                                           org.elasticsearch.env.ShardLockObtainFailedException::new, 147, Version.V_5_0_2);
+                                           org.elasticsearch.env.ShardLockObtainFailedException::new, 147, Version.V_5_0_2),
+        UNKNOWN_NAMED_OBJECT_EXCEPTION(org.elasticsearch.common.xcontent.NamedXContentRegistry.UnknownNamedObjectException.class,
+                org.elasticsearch.common.xcontent.NamedXContentRegistry.UnknownNamedObjectException::new, 148, Version.V_5_2_0_UNRELEASED);
 
         final Class<? extends ElasticsearchException> exceptionClass;
         final FunctionThatThrowsIOException<StreamInput, ? extends ElasticsearchException> constructor;

core/src/main/java/org/elasticsearch/ElasticsearchParseException.java

@@ -24,6 +24,9 @@ import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
 
+/**
+ * Unchecked exception that is translated into a {@code 400 BAD REQUEST} error when it bubbles out over HTTP.
+ */
 public class ElasticsearchParseException extends ElasticsearchException {
 
     public ElasticsearchParseException(String msg, Object... args) {

core/src/main/java/org/elasticsearch/action/DocWriteResponse.java

@@ -35,6 +35,8 @@ import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.Locale;
 
 /**
@@ -186,8 +188,9 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
     /**
      * Gets the location of the written document as a string suitable for a {@code Location} header.
      * @param routing any routing used in the request. If null the location doesn't include routing information.
+     *
      */
-    public String getLocation(@Nullable String routing) {
+    public String getLocation(@Nullable String routing) throws URISyntaxException {
         // Absolute path for the location of the document. This should be allowed as of HTTP/1.1:
         // https://tools.ietf.org/html/rfc7231#section-7.1.2
         String index = getIndex();
@@ -205,7 +208,9 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
         if (routing != null) {
             location.append(routingStart).append(routing);
         }
-        return location.toString();
+
+        URI uri = new URI(location.toString());
+        return uri.toASCIIString();
     }
 
     @Override

core/src/main/java/org/elasticsearch/action/admin/cluster/health/TransportClusterHealthAction.java

@@ -141,8 +141,8 @@ public class TransportClusterHealthAction extends TransportMasterNodeReadAction<
         }
 
         assert waitFor >= 0;
-        final ClusterStateObserver observer = new ClusterStateObserver(clusterService, logger, threadPool.getThreadContext());
-        final ClusterState state = observer.observedState();
+        final ClusterState state = clusterService.state();
+        final ClusterStateObserver observer = new ClusterStateObserver(state, clusterService, null, logger, threadPool.getThreadContext());
         if (request.timeout().millis() == 0) {
             listener.onResponse(getResponse(request, state, waitFor, request.timeout().millis() == 0));
             return;
@@ -163,8 +163,7 @@ public class TransportClusterHealthAction extends TransportMasterNodeReadAction<
 
             @Override
             public void onTimeout(TimeValue timeout) {
-                final ClusterState clusterState = clusterService.state();
-                final ClusterHealthResponse response = getResponse(request, clusterState, concreteWaitFor, true);
+                final ClusterHealthResponse response = getResponse(request, observer.setAndGetObservedState(), concreteWaitFor, true);
                 listener.onResponse(response);
             }
         };

core/src/main/java/org/elasticsearch/action/admin/cluster/node/tasks/get/TransportGetTaskAction.java

@@ -35,6 +35,7 @@ import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.AbstractRunnable;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.IndexNotFoundException;
@@ -67,14 +68,17 @@ public class TransportGetTaskAction extends HandledTransportAction<GetTaskReques
     private final ClusterService clusterService;
     private final TransportService transportService;
     private final Client client;
+    private final NamedXContentRegistry xContentRegistry;
 
     @Inject
     public TransportGetTaskAction(Settings settings, ThreadPool threadPool, TransportService transportService, ActionFilters actionFilters,
-            IndexNameExpressionResolver indexNameExpressionResolver, ClusterService clusterService, Client client) {
+            IndexNameExpressionResolver indexNameExpressionResolver, ClusterService clusterService, Client client,
+            NamedXContentRegistry xContentRegistry) {
         super(settings, GetTaskAction.NAME, threadPool, transportService, actionFilters, indexNameExpressionResolver, GetTaskRequest::new);
         this.clusterService = clusterService;
         this.transportService = transportService;
         this.client = client;
+        this.xContentRegistry = xContentRegistry;
     }
 
     @Override
@@ -246,7 +250,7 @@ public class TransportGetTaskAction extends HandledTransportAction<GetTaskReques
             listener.onFailure(new ElasticsearchException("Stored task status for [{}] didn't contain any source!", response.getId()));
             return;
         }
-        try (XContentParser parser = XContentHelper.createParser(response.getSourceAsBytesRef())) {
+        try (XContentParser parser = XContentHelper.createParser(xContentRegistry, response.getSourceAsBytesRef())) {
             TaskResult result = TaskResult.PARSER.apply(parser, () -> ParseFieldMatcher.STRICT);
             listener.onResponse(new GetTaskResponse(result));
         }

core/src/main/java/org/elasticsearch/action/admin/indices/create/CreateIndexRequest.java

@@ -35,6 +35,7 @@ import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
@@ -307,7 +308,8 @@ public class CreateIndexRequest extends AcknowledgedRequest<CreateIndexRequest>
      * Sets the aliases that will be associated with the index when it gets created
      */
     public CreateIndexRequest aliases(BytesReference source) {
-        try (XContentParser parser = XContentHelper.createParser(source)) {
+        // EMPTY is safe here because we never call namedObject
+        try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, source)) {
             //move to the first alias
             parser.nextToken();
             while ((parser.nextToken()) != XContentParser.Token.END_OBJECT) {
@@ -361,11 +363,7 @@ public class CreateIndexRequest extends AcknowledgedRequest<CreateIndexRequest>
     public CreateIndexRequest source(BytesReference source) {
         XContentType xContentType = XContentFactory.xContentType(source);
         if (xContentType != null) {
-            try (XContentParser parser = XContentFactory.xContent(xContentType).createParser(source)) {
-                source(parser.map());
-            } catch (IOException e) {
-                throw new ElasticsearchParseException("failed to parse source for create index", e);
-            }
+            source(XContentHelper.convertToMap(source, false).v2());
         } else {
             settings(source.utf8ToString());
         }

core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequest.java

@@ -36,6 +36,7 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
@@ -351,11 +352,7 @@ public class PutIndexTemplateRequest extends MasterNodeRequest<PutIndexTemplateR
      * The template source definition.
      */
     public PutIndexTemplateRequest source(String templateSource) {
-        try (XContentParser parser = XContentFactory.xContent(templateSource).createParser(templateSource)) {
-            return source(parser.mapOrdered());
-        } catch (Exception e) {
-            throw new IllegalArgumentException("failed to parse template source [" + templateSource + "]", e);
-        }
+        return source(XContentHelper.convertToMap(XContentFactory.xContent(templateSource), templateSource, true));
     }
 
     /**
@@ -369,22 +366,14 @@ public class PutIndexTemplateRequest extends MasterNodeRequest<PutIndexTemplateR
      * The template source definition.
      */
     public PutIndexTemplateRequest source(byte[] source, int offset, int length) {
-        try (XContentParser parser = XContentFactory.xContent(source, offset, length).createParser(source, offset, length)) {
-            return source(parser.mapOrdered());
-        } catch (IOException e) {
-            throw new IllegalArgumentException("failed to parse template source", e);
-        }
+        return source(new BytesArray(source, offset, length));
     }
 
     /**
      * The template source definition.
      */
     public PutIndexTemplateRequest source(BytesReference source) {
-        try (XContentParser parser = XContentFactory.xContent(source).createParser(source)) {
-            return source(parser.mapOrdered());
-        } catch (IOException e) {
-            throw new IllegalArgumentException("failed to parse template source", e);
-        }
+        return source(XContentHelper.convertToMap(source, true).v2());
     }
 
     public PutIndexTemplateRequest custom(IndexMetaData.Custom custom) {
@@ -432,7 +421,8 @@ public class PutIndexTemplateRequest extends MasterNodeRequest<PutIndexTemplateR
      * Sets the aliases that will be associated with the index when it gets created
      */
     public PutIndexTemplateRequest aliases(BytesReference source) {
-        try (XContentParser parser = XContentHelper.createParser(source)) {
+        // EMPTY is safe here because we never call namedObject
+        try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, source)) {
             //move to the first alias
             parser.nextToken();
             while ((parser.nextToken()) != XContentParser.Token.END_OBJECT) {

core/src/main/java/org/elasticsearch/action/bulk/BulkRequest.java

@@ -39,6 +39,7 @@ import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.lucene.uid.Versions;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -283,7 +284,8 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
             line++;
 
             // now parse the action
-            try (XContentParser parser = xContent.createParser(data.slice(from, nextMarker - from))) {
+            // EMPTY is safe here because we never call namedObject
+            try (XContentParser parser = xContent.createParser(NamedXContentRegistry.EMPTY, data.slice(from, nextMarker - from))) {
                 // move pointers
                 from = nextMarker + 1;
 
@@ -400,7 +402,8 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
                                 .version(version).versionType(versionType)
                                 .routing(routing)
                                 .parent(parent);
-                        try (XContentParser sliceParser = xContent.createParser(data.slice(from, nextMarker - from))) {
+                        // EMPTY is safe here because we never call namedObject
+                        try (XContentParser sliceParser = xContent.createParser(NamedXContentRegistry.EMPTY, data.slice(from, nextMarker - from))) {
                             updateRequest.fromXContent(sliceParser);
                         }
                         if (fetchSourceContext != null) {

core/src/main/java/org/elasticsearch/action/bulk/TransportBulkAction.java

@@ -240,7 +240,7 @@ public class TransportBulkAction extends HandledTransportAction<BulkRequest, Bul
 
         @Override
         protected void doRun() throws Exception {
-            final ClusterState clusterState = observer.observedState();
+            final ClusterState clusterState = observer.setAndGetObservedState();
             if (handleBlockExceptions(clusterState)) {
                 return;
             }

core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -109,7 +109,6 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
             BulkShardRequest request, IndexShard primary) throws Exception {
         final IndexMetaData metaData = primary.indexSettings().getIndexMetaData();
 
-        logger.info("TTRACE: in bulk shardOperationPrimary for [{}]", request);
         long[] preVersions = new long[request.items().length];
         VersionType[] preVersionTypes = new VersionType[request.items().length];
         Translog.Location location = null;
@@ -365,7 +364,6 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
 
     @Override
     public WriteReplicaResult<BulkShardRequest> shardOperationOnReplica(BulkShardRequest request, IndexShard replica) throws Exception {
-        logger.info("TTRACE: in bulk shardOperationReplica for [{}]", request);
         Translog.Location location = null;
         for (int i = 0; i < request.items().length; i++) {
             BulkItemRequest item = request.items()[i];

core/src/main/java/org/elasticsearch/action/get/GetResponse.java

@@ -27,12 +27,14 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.get.GetField;
 import org.elasticsearch.index.get.GetResult;
 
 import java.io.IOException;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * The response of a get action.
@@ -42,7 +44,7 @@ import java.util.Map;
  */
 public class GetResponse extends ActionResponse implements Iterable<GetField>, ToXContent {
 
-    private GetResult getResult;
+    GetResult getResult;
 
     GetResponse() {
     }
@@ -156,6 +158,11 @@ public class GetResponse extends ActionResponse implements Iterable<GetField>, T
         return getResult.toXContent(builder, params);
     }
 
+    public static GetResponse fromXContent(XContentParser parser) throws IOException {
+        GetResult getResult = GetResult.fromXContent(parser);
+        return new GetResponse(getResult);
+    }
+
     @Override
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
@@ -168,6 +175,23 @@ public class GetResponse extends ActionResponse implements Iterable<GetField>, T
         getResult.writeTo(out);
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        GetResponse getResponse = (GetResponse) o;
+        return Objects.equals(getResult, getResponse.getResult);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(getResult);
+    }
+
     @Override
     public String toString() {
         return Strings.toString(this, true);

core/src/main/java/org/elasticsearch/action/get/MultiGetResponse.java

@@ -140,9 +140,7 @@ public class MultiGetResponse extends ActionResponse implements Iterable<MultiGe
                 builder.endObject();
             } else {
                 GetResponse getResponse = response.getResponse();
-                builder.startObject();
                 getResponse.toXContent(builder, params);
-                builder.endObject();
             }
         }
         builder.endArray();
@@ -154,9 +152,6 @@ public class MultiGetResponse extends ActionResponse implements Iterable<MultiGe
         static final String _INDEX = "_index";
         static final String _TYPE = "_type";
         static final String _ID = "_id";
-        static final String ERROR = "error";
-        static final String ROOT_CAUSE = "root_cause";
-
     }
 
     @Override

core/src/main/java/org/elasticsearch/action/support/ActiveShardsObserver.java

@@ -69,9 +69,10 @@ public class ActiveShardsObserver extends AbstractComponent {
             return;
         }
 
-        final ClusterStateObserver observer = new ClusterStateObserver(clusterService, logger, threadPool.getThreadContext());
-        if (activeShardCount.enoughShardsActive(observer.observedState(), indexName)) {
-                onResult.accept(true);
+        final ClusterState state = clusterService.state();
+        final ClusterStateObserver observer = new ClusterStateObserver(state, clusterService, null, logger, threadPool.getThreadContext());
+        if (activeShardCount.enoughShardsActive(state, indexName)) {
+            onResult.accept(true);
         } else {
             final Predicate<ClusterState> shardsAllocatedPredicate = newState -> activeShardCount.enoughShardsActive(newState, indexName);
 

core/src/main/java/org/elasticsearch/action/support/master/TransportMasterNodeAction.java

@@ -121,12 +121,12 @@ public abstract class TransportMasterNodeAction<Request extends MasterNodeReques
         }
 
         public void start() {
-            this.observer = new ClusterStateObserver(clusterService, request.masterNodeTimeout(), logger, threadPool.getThreadContext());
-            doStart();
+            ClusterState state = clusterService.state();
+            this.observer = new ClusterStateObserver(state, clusterService, request.masterNodeTimeout(), logger, threadPool.getThreadContext());
+            doStart(state);
         }
 
-        protected void doStart() {
-            final ClusterState clusterState = observer.observedState();
+        protected void doStart(ClusterState clusterState) {
             final Predicate<ClusterState> masterChangePredicate = MasterNodeChangePredicate.build(clusterState);
             final DiscoveryNodes nodes = clusterState.nodes();
             if (nodes.isLocalNodeElectedMaster() || localExecute(request)) {
@@ -197,7 +197,7 @@ public abstract class TransportMasterNodeAction<Request extends MasterNodeReques
                 new ClusterStateObserver.Listener() {
                     @Override
                     public void onNewClusterState(ClusterState state) {
-                        doStart();
+                        doStart(state);
                     }
 
                     @Override

core/src/main/java/org/elasticsearch/action/support/replication/ReplicationResponse.java

@@ -23,19 +23,26 @@ import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.action.ShardOperationFailedException;
+import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Streamable;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
 
+import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
+import static org.elasticsearch.common.xcontent.XContentParserUtils.throwUnknownField;
+
 /**
  * Base class for write action responses.
  */
@@ -186,6 +193,48 @@ public class ReplicationResponse extends ActionResponse {
             return builder;
         }
 
+        public static ShardInfo fromXContent(XContentParser parser) throws IOException {
+            XContentParser.Token token = parser.nextToken();
+            ensureExpectedToken(XContentParser.Token.FIELD_NAME, token, parser::getTokenLocation);
+
+            String currentFieldName = parser.currentName();
+            if (_SHARDS.equals(currentFieldName) == false) {
+                throwUnknownField(currentFieldName, parser.getTokenLocation());
+            }
+            token = parser.nextToken();
+            ensureExpectedToken(XContentParser.Token.START_OBJECT, token, parser::getTokenLocation);
+
+            int total = 0, successful = 0;
+            List<Failure> failuresList = null;
+            while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+                if (token == XContentParser.Token.FIELD_NAME) {
+                    currentFieldName = parser.currentName();
+                } else if (token.isValue()) {
+                    if (TOTAL.equals(currentFieldName)) {
+                        total = parser.intValue();
+                    } else if (SUCCESSFUL.equals(currentFieldName)) {
+                        successful = parser.intValue();
+                    } else if (FAILED.equals(currentFieldName) == false) {
+                        throwUnknownField(currentFieldName, parser.getTokenLocation());
+                    }
+                } else if (token == XContentParser.Token.START_ARRAY) {
+                    if (FAILURES.equals(currentFieldName)) {
+                        failuresList = new ArrayList<>();
+                        while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
+                            failuresList.add(Failure.fromXContent(parser));
+                        }
+                    } else {
+                        throwUnknownField(currentFieldName, parser.getTokenLocation());
+                    }
+                }
+            }
+            Failure[] failures = EMPTY;
+            if (failuresList != null) {
+                failures = failuresList.toArray(new Failure[failuresList.size()]);
+            }
+            return new ShardInfo(total, successful, failures);
+        }
+
         @Override
         public String toString() {
             return "ShardInfo{" +
@@ -338,6 +387,45 @@ public class ReplicationResponse extends ActionResponse {
                 builder.endObject();
                 return builder;
             }
+
+            public static Failure fromXContent(XContentParser parser) throws IOException {
+                XContentParser.Token token = parser.currentToken();
+                ensureExpectedToken(XContentParser.Token.START_OBJECT, token, parser::getTokenLocation);
+
+                String shardIndex = null, nodeId = null;
+                int shardId = -1;
+                boolean primary = false;
+                RestStatus status = null;
+                ElasticsearchException reason = null;
+
+                String currentFieldName = null;
+                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+                    if (token == XContentParser.Token.FIELD_NAME) {
+                        currentFieldName = parser.currentName();
+                    } else if (token.isValue()) {
+                        if (_INDEX.equals(currentFieldName)) {
+                            shardIndex = parser.text();
+                        } else if (_SHARD.equals(currentFieldName)) {
+                            shardId = parser.intValue();
+                        } else if (_NODE.equals(currentFieldName)) {
+                            nodeId = parser.text();
+                        } else if (STATUS.equals(currentFieldName)) {
+                            status = RestStatus.valueOf(parser.text());
+                        } else if (PRIMARY.equals(currentFieldName)) {
+                            primary = parser.booleanValue();
+                        } else {
+                            throwUnknownField(currentFieldName, parser.getTokenLocation());
+                        }
+                    } else if (token == XContentParser.Token.START_OBJECT) {
+                        if (REASON.equals(currentFieldName)) {
+                            reason = ElasticsearchException.fromXContent(parser);
+                        } else {
+                            throwUnknownField(currentFieldName, parser.getTokenLocation());
+                        }
+                    }
+                }
+                return new Failure(new ShardId(shardIndex, IndexMetaData.INDEX_UUID_NA_VALUE, shardId), nodeId, reason, status, primary);
+            }
         }
     }
 }

core/src/main/java/org/elasticsearch/action/support/replication/TransportReplicationAction.java

@@ -638,7 +638,7 @@ public abstract class TransportReplicationAction<
         @Override
         protected void doRun() {
             setPhase(task, "routing");
-            final ClusterState state = observer.observedState();
+            final ClusterState state = observer.setAndGetObservedState();
             if (handleBlockExceptions(state)) {
                 return;
             }

core/src/main/java/org/elasticsearch/action/support/single/instance/TransportInstanceSingleOperationAction.java

@@ -111,7 +111,6 @@ public abstract class TransportInstanceSingleOperationAction<Request extends Ins
         private final Request request;
         private volatile ClusterStateObserver observer;
         private ShardIterator shardIt;
-        private DiscoveryNodes nodes;
 
         AsyncSingleAction(Request request, ActionListener<Response> listener) {
             this.request = request;
@@ -119,13 +118,12 @@ public abstract class TransportInstanceSingleOperationAction<Request extends Ins
         }
 
         public void start() {
-            this.observer = new ClusterStateObserver(clusterService, request.timeout(), logger, threadPool.getThreadContext());
-            doStart();
+            ClusterState state = clusterService.state();
+            this.observer = new ClusterStateObserver(state, clusterService, request.timeout(), logger, threadPool.getThreadContext());
+            doStart(state);
         }
 
-        protected void doStart() {
-            final ClusterState clusterState = observer.observedState();
-            nodes = clusterState.nodes();
+        protected void doStart(ClusterState clusterState) {
             try {
                 ClusterBlockException blockException = checkGlobalBlock(clusterState);
                 if (blockException != null) {
@@ -171,7 +169,7 @@ public abstract class TransportInstanceSingleOperationAction<Request extends Ins
             }
 
             request.shardId = shardIt.shardId();
-            DiscoveryNode node = nodes.get(shard.currentNodeId());
+            DiscoveryNode node = clusterState.nodes().get(shard.currentNodeId());
             transportService.sendRequest(node, shardActionName, request, transportOptions(), new TransportResponseHandler<Response>() {
 
                 @Override
@@ -221,18 +219,18 @@ public abstract class TransportInstanceSingleOperationAction<Request extends Ins
             observer.waitForNextChange(new ClusterStateObserver.Listener() {
                 @Override
                 public void onNewClusterState(ClusterState state) {
-                    doStart();
+                    doStart(state);
                 }
 
                 @Override
                 public void onClusterServiceClose() {
-                    listener.onFailure(new NodeClosedException(nodes.getLocalNode()));
+                    listener.onFailure(new NodeClosedException(clusterService.localNode()));
                 }
 
                 @Override
                 public void onTimeout(TimeValue timeout) {
                     // just to be on the safe side, see if we can start it now?
-                    doStart();
+                    doStart(observer.setAndGetObservedState());
                 }
             }, request.timeout());
         }

core/src/main/java/org/elasticsearch/bootstrap/Bootstrap.java

@@ -58,9 +58,7 @@ import java.net.URISyntaxException;
 import java.nio.file.Path;
 import java.security.NoSuchAlgorithmException;
 import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Objects;
+import java.util.Collections;
 import java.util.concurrent.CountDownLatch;
 
 /**
@@ -226,13 +224,14 @@ final class Bootstrap {
         };
     }
 
-    private static Environment initialEnvironment(boolean foreground, Path pidFile, Map<String, String> esSettings) {
+    private static Environment initialEnvironment(boolean foreground, Path pidFile, Settings initialSettings) {
         Terminal terminal = foreground ? Terminal.DEFAULT : null;
         Settings.Builder builder = Settings.builder();
         if (pidFile != null) {
             builder.put(Environment.PIDFILE_SETTING.getKey(), pidFile);
         }
-        return InternalSettingsPreparer.prepareEnvironment(builder.build(), terminal, esSettings);
+        builder.put(initialSettings);
+        return InternalSettingsPreparer.prepareEnvironment(builder.build(), terminal, Collections.emptyMap());
     }
 
     private void start() throws NodeValidationException {
@@ -262,7 +261,7 @@ final class Bootstrap {
             final boolean foreground,
             final Path pidFile,
             final boolean quiet,
-            final Map<String, String> esSettings) throws BootstrapException, NodeValidationException, UserException {
+            final Settings initialSettings) throws BootstrapException, NodeValidationException, UserException {
         // Set the system property before anything has a chance to trigger its use
         initLoggerPrefix();
 
@@ -272,7 +271,7 @@ final class Bootstrap {
 
         INSTANCE = new Bootstrap();
 
-        Environment environment = initialEnvironment(foreground, pidFile, esSettings);
+        Environment environment = initialEnvironment(foreground, pidFile, initialSettings);
         try {
             LogConfigurator.configure(environment);
         } catch (IOException e) {

core/src/main/java/org/elasticsearch/bootstrap/BootstrapException.java

@@ -20,14 +20,14 @@
 package org.elasticsearch.bootstrap;
 
 import java.nio.file.Path;
-import java.util.Map;
 
 /**
  * Wrapper exception for checked exceptions thrown during the bootstrap process. Methods invoked
  * during bootstrap should explicitly declare the checked exceptions that they can throw, rather
  * than declaring the top-level checked exception {@link Exception}. This exception exists to wrap
- * these checked exceptions so that {@link Bootstrap#init(boolean, Path, boolean, Map)} does not have to
- * declare all of these checked exceptions.
+ * these checked exceptions so that
+ * {@link Bootstrap#init(boolean, Path, boolean, org.elasticsearch.common.settings.Settings)}
+ * does not have to declare all of these checked exceptions.
  */
 class BootstrapException extends Exception {
 

core/src/main/java/org/elasticsearch/bootstrap/Elasticsearch.java

@@ -25,9 +25,11 @@ import joptsimple.OptionSpecBuilder;
 import joptsimple.util.PathConverter;
 import org.elasticsearch.Build;
 import org.elasticsearch.cli.ExitCodes;
-import org.elasticsearch.cli.SettingCommand;
+import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.cli.UserException;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.env.Environment;
 import org.elasticsearch.monitor.jvm.JvmInfo;
 import org.elasticsearch.node.NodeValidationException;
 
@@ -40,7 +42,7 @@ import java.util.Map;
 /**
  * This class starts elasticsearch.
  */
-class Elasticsearch extends SettingCommand {
+class Elasticsearch extends EnvironmentAwareCommand {
 
     private final OptionSpecBuilder versionOption;
     private final OptionSpecBuilder daemonizeOption;
@@ -90,7 +92,7 @@ class Elasticsearch extends SettingCommand {
     }
 
     @Override
-    protected void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws UserException {
+    protected void execute(Terminal terminal, OptionSet options, Environment env) throws UserException {
         if (options.nonOptionArguments().isEmpty() == false) {
             throw new UserException(ExitCodes.USAGE, "Positional arguments not allowed, found " + options.nonOptionArguments());
         }
@@ -109,16 +111,16 @@ class Elasticsearch extends SettingCommand {
         final boolean quiet = options.has(quietOption);
 
         try {
-            init(daemonize, pidFile, quiet, settings);
+            init(daemonize, pidFile, quiet, env.settings());
         } catch (NodeValidationException e) {
             throw new UserException(ExitCodes.CONFIG, e.getMessage());
         }
     }
 
-    void init(final boolean daemonize, final Path pidFile, final boolean quiet, final Map<String, String> esSettings)
+    void init(final boolean daemonize, final Path pidFile, final boolean quiet, Settings initialSettings)
         throws NodeValidationException, UserException {
         try {
-            Bootstrap.init(!daemonize, pidFile, quiet, esSettings);
+            Bootstrap.init(!daemonize, pidFile, quiet, initialSettings);
         } catch (BootstrapException | RuntimeException e) {
             // format exceptions to the console in a special way
             // to avoid 2MB stacktraces from guice, etc.

core/src/main/java/org/elasticsearch/cli/EnvironmentAwareCommand.java

@@ -22,16 +22,20 @@ package org.elasticsearch.cli;
 import joptsimple.OptionSet;
 import joptsimple.OptionSpec;
 import joptsimple.util.KeyValuePair;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.env.Environment;
+import org.elasticsearch.node.internal.InternalSettingsPreparer;
 
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
-public abstract class SettingCommand extends Command {
+/** A cli command which requires an {@link org.elasticsearch.env.Environment} to use current paths and settings. */
+public abstract class EnvironmentAwareCommand extends Command {
 
     private final OptionSpec<KeyValuePair> settingOption;
 
-    public SettingCommand(String description) {
+    public EnvironmentAwareCommand(String description) {
         super(description);
         this.settingOption = parser.accepts("E", "Configure a setting").withRequiredArg().ofType(KeyValuePair.class);
     }
@@ -51,9 +55,15 @@ public abstract class SettingCommand extends Command {
         putSystemPropertyIfSettingIsMissing(settings, "path.home", "es.path.home");
         putSystemPropertyIfSettingIsMissing(settings, "path.logs", "es.path.logs");
 
-        execute(terminal, options, settings);
+        execute(terminal, options, createEnv(terminal, settings));
     }
 
+    /** Create an {@link Environment} for the command to use. Overrideable for tests. */
+    protected Environment createEnv(Terminal terminal, Map<String, String> settings) {
+        return InternalSettingsPreparer.prepareEnvironment(Settings.EMPTY, terminal, settings);
+    }
+
+    /** Ensure the given setting exists, reading it from system properties if not already set. */
     protected static void putSystemPropertyIfSettingIsMissing(final Map<String, String> settings, final String setting, final String key) {
         final String value = System.getProperty(key);
         if (value != null) {
@@ -72,6 +82,7 @@ public abstract class SettingCommand extends Command {
         }
     }
 
-    protected abstract void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws Exception;
+    /** Execute the command with the initialized {@link Environment}. */
+    protected abstract void execute(Terminal terminal, OptionSet options, Environment env) throws Exception;
 
 }

core/src/main/java/org/elasticsearch/client/transport/TransportClient.java

@@ -41,6 +41,7 @@ import org.elasticsearch.common.settings.SettingsModule;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.BigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.node.Node;
 import org.elasticsearch.node.internal.InternalSettingsPreparer;
@@ -63,8 +64,11 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
+import static java.util.stream.Collectors.toList;
 import static org.elasticsearch.common.unit.TimeValue.timeValueSeconds;
 
 /**
@@ -140,6 +144,11 @@ public abstract class TransportClient extends AbstractClient {
                                          .flatMap(p -> p.getNamedWriteables().stream())
                                          .collect(Collectors.toList()));
             NamedWriteableRegistry namedWriteableRegistry = new NamedWriteableRegistry(entries);
+            NamedXContentRegistry xContentRegistry = new NamedXContentRegistry(Stream.of(
+                    searchModule.getNamedXContents().stream(),
+                    pluginsService.filterPlugins(Plugin.class).stream()
+                            .flatMap(p -> p.getNamedXContent().stream())
+                    ).flatMap(Function.identity()).collect(toList()));
 
             ModulesBuilder modules = new ModulesBuilder();
             // plugin modules must be added here, before others or we can get crazy injection errors...
@@ -158,7 +167,7 @@ public abstract class TransportClient extends AbstractClient {
             resourcesToClose.add(bigArrays);
             modules.add(settingsModule);
             NetworkModule networkModule = new NetworkModule(settings, true, pluginsService.filterPlugins(NetworkPlugin.class), threadPool,
-                bigArrays, circuitBreakerService, namedWriteableRegistry, networkService);
+                bigArrays, circuitBreakerService, namedWriteableRegistry, xContentRegistry, networkService);
             final Transport transport = networkModule.getTransportSupplier().get();
             final TransportService transportService = new TransportService(settings, transport, threadPool,
                 networkModule.getTransportInterceptor(), null);

core/src/main/java/org/elasticsearch/cluster/ClusterState.java

@@ -22,6 +22,7 @@ package org.elasticsearch.cluster;
 import com.carrotsearch.hppc.cursors.IntObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
+
 import org.elasticsearch.cluster.block.ClusterBlock;
 import org.elasticsearch.cluster.block.ClusterBlocks;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
@@ -40,6 +41,7 @@ import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.UUIDs;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.compress.CompressedXContent;
@@ -49,8 +51,7 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.common.xcontent.XContentFactory;
-import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.discovery.Discovery;
 import org.elasticsearch.discovery.zen.PublishClusterStateAction;
 
@@ -403,11 +404,7 @@ public class ClusterState implements ToXContent, Diffable<ClusterState> {
 
                 builder.startObject("mappings");
                 for (ObjectObjectCursor<String, CompressedXContent> cursor1 : templateMetaData.mappings()) {
-                    byte[] mappingSource = cursor1.value.uncompressed();
-                    Map<String, Object> mapping;
-                    try (XContentParser parser = XContentFactory.xContent(mappingSource).createParser(mappingSource)) {
-                        mapping = parser.map();
-                    }
+                    Map<String, Object> mapping = XContentHelper.convertToMap(new BytesArray(cursor1.value.uncompressed()), false).v2();
                     if (mapping.size() == 1 && mapping.containsKey(cursor1.key)) {
                         // the type name is the root value, reduce it
                         mapping = (Map<String, Object>) mapping.get(cursor1.key);
@@ -435,11 +432,8 @@ public class ClusterState implements ToXContent, Diffable<ClusterState> {
 
                 builder.startObject("mappings");
                 for (ObjectObjectCursor<String, MappingMetaData> cursor : indexMetaData.getMappings()) {
-                    byte[] mappingSource = cursor.value.source().uncompressed();
-                    Map<String, Object> mapping;
-                    try (XContentParser parser = XContentFactory.xContent(mappingSource).createParser(mappingSource)) {
-                        mapping = parser.map();
-                    }
+                    Map<String, Object> mapping = XContentHelper
+                            .convertToMap(new BytesArray(cursor.value.source().uncompressed()), false).v2();
                     if (mapping.size() == 1 && mapping.containsKey(cursor.key)) {
                         // the type name is the root value, reduce it
                         mapping = (Map<String, Object>) mapping.get(cursor.key);

core/src/main/java/org/elasticsearch/cluster/ClusterStateObserver.java

@@ -26,6 +26,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Predicate;
 
@@ -45,7 +46,7 @@ public class ClusterStateObserver {
     volatile TimeValue timeOutValue;
 
 
-    final AtomicReference<ClusterState> lastObservedState;
+    final AtomicReference<StoredState> lastObservedState;
     final TimeoutClusterStateListener clusterStateListener = new ObserverClusterStateListener();
     // observingContext is not null when waiting on cluster state changes
     final AtomicReference<ObservingContext> observingContext = new AtomicReference<>(null);
@@ -73,7 +74,7 @@ public class ClusterStateObserver {
     public ClusterStateObserver(ClusterState initialState, ClusterService clusterService, @Nullable TimeValue timeout, Logger logger,
                                 ThreadContext contextHolder) {
         this.clusterService = clusterService;
-        this.lastObservedState = new AtomicReference<>(initialState);
+        this.lastObservedState = new AtomicReference<>(new StoredState(initialState));
         this.timeOutValue = timeout;
         if (timeOutValue != null) {
             this.startTimeNS = System.nanoTime();
@@ -82,11 +83,14 @@ public class ClusterStateObserver {
         this.contextHolder = contextHolder;
     }
 
-    /** last cluster state and status observed by this observer. Note that this may not be the current one */
-    public ClusterState observedState() {
-        ClusterState state = lastObservedState.get();
-        assert state != null;
-        return state;
+    /** sets the last observed state to the currently applied cluster state and returns it */
+    public ClusterState setAndGetObservedState() {
+        if (observingContext.get() != null) {
+            throw new ElasticsearchException("cannot set current cluster state while waiting for a cluster state change");
+        }
+        ClusterState clusterState = clusterService.state();
+        lastObservedState.set(new StoredState(clusterState));
+        return clusterState;
     }
 
     /** indicates whether this observer has timedout */
@@ -130,7 +134,7 @@ public class ClusterStateObserver {
                     logger.trace("observer timed out. notifying listener. timeout setting [{}], time since start [{}]", timeOutValue, new TimeValue(timeSinceStartMS));
                     // update to latest, in case people want to retry
                     timedOut = true;
-                    lastObservedState.set(clusterService.state());
+                    lastObservedState.set(new StoredState(clusterService.state()));
                     listener.onTimeout(timeOutValue);
                     return;
                 }
@@ -146,11 +150,10 @@ public class ClusterStateObserver {
 
         // sample a new state
         ClusterState newState = clusterService.state();
-        ClusterState lastState = lastObservedState.get();
-        if (newState != lastState && statePredicate.test(newState)) {
+        if (lastObservedState.get().sameState(newState) == false && statePredicate.test(newState)) {
             // good enough, let's go.
             logger.trace("observer: sampled state accepted by predicate ({})", newState);
-            lastObservedState.set(newState);
+            lastObservedState.set(new StoredState(newState));
             listener.onNewClusterState(newState);
         } else {
             logger.trace("observer: sampled state rejected by predicate ({}). adding listener to ClusterService", newState);
@@ -177,7 +180,7 @@ public class ClusterStateObserver {
                 if (observingContext.compareAndSet(context, null)) {
                     clusterService.removeTimeoutListener(this);
                     logger.trace("observer: accepting cluster state change ({})", state);
-                    lastObservedState.set(state);
+                    lastObservedState.set(new StoredState(state));
                     context.listener.onNewClusterState(state);
                 } else {
                     logger.trace("observer: predicate approved change but observing context has changed - ignoring (new cluster state version [{}])", state.version());
@@ -195,13 +198,12 @@ public class ClusterStateObserver {
                 return;
             }
             ClusterState newState = clusterService.state();
-            ClusterState lastState = lastObservedState.get();
-            if (newState != lastState && context.statePredicate.test(newState)) {
+            if (lastObservedState.get().sameState(newState) == false && context.statePredicate.test(newState)) {
                 // double check we're still listening
                 if (observingContext.compareAndSet(context, null)) {
                     logger.trace("observer: post adding listener: accepting current cluster state ({})", newState);
                     clusterService.removeTimeoutListener(this);
-                    lastObservedState.set(newState);
+                    lastObservedState.set(new StoredState(newState));
                     context.listener.onNewClusterState(newState);
                 } else {
                     logger.trace("observer: postAdded - predicate approved state but observing context has changed - ignoring ({})", newState);
@@ -230,13 +232,30 @@ public class ClusterStateObserver {
                 long timeSinceStartMS = TimeValue.nsecToMSec(System.nanoTime() - startTimeNS);
                 logger.trace("observer: timeout notification from cluster service. timeout setting [{}], time since start [{}]", timeOutValue, new TimeValue(timeSinceStartMS));
                 // update to latest, in case people want to retry
-                lastObservedState.set(clusterService.state());
+                lastObservedState.set(new StoredState(clusterService.state()));
                 timedOut = true;
                 context.listener.onTimeout(timeOutValue);
             }
         }
     }
 
+    /**
+     * The observer considers two cluster states to be the same if they have the same version and master node id (i.e. null or set)
+     */
+    private static class StoredState {
+        private final String masterNodeId;
+        private final long version;
+
+        public StoredState(ClusterState clusterState) {
+            this.masterNodeId = clusterState.nodes().getMasterNodeId();
+            this.version = clusterState.version();
+        }
+
+        public boolean sameState(ClusterState clusterState) {
+            return version == clusterState.version() && Objects.equals(masterNodeId, clusterState.nodes().getMasterNodeId());
+        }
+    }
+
     public interface Listener {
 
         /** called when a new state is observed */

core/src/main/java/org/elasticsearch/cluster/action/shard/ShardStateAction.java

@@ -69,6 +69,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
+import java.util.function.Predicate;
 
 public class ShardStateAction extends AbstractComponent {
 
@@ -91,11 +92,13 @@ public class ShardStateAction extends AbstractComponent {
         transportService.registerRequestHandler(SHARD_FAILED_ACTION_NAME, ShardEntry::new, ThreadPool.Names.SAME, new ShardFailedTransportHandler(clusterService, new ShardFailedClusterStateTaskExecutor(allocationService, routingService, logger), logger));
     }
 
-    private void sendShardAction(final String actionName, final ClusterStateObserver observer, final ShardEntry shardEntry, final Listener listener) {
-        DiscoveryNode masterNode = observer.observedState().nodes().getMasterNode();
+    private void sendShardAction(final String actionName, final ClusterState currentState, final ShardEntry shardEntry, final Listener listener) {
+        ClusterStateObserver observer = new ClusterStateObserver(currentState, clusterService, null, logger, threadPool.getThreadContext());
+        DiscoveryNode masterNode = currentState.nodes().getMasterNode();
+        Predicate<ClusterState> changePredicate = MasterNodeChangePredicate.build(currentState);
         if (masterNode == null) {
             logger.warn("{} no master known for action [{}] for shard entry [{}]", shardEntry.shardId, actionName, shardEntry);
-            waitForNewMasterAndRetry(actionName, observer, shardEntry, listener);
+            waitForNewMasterAndRetry(actionName, observer, shardEntry, listener, changePredicate);
         } else {
             logger.debug("{} sending [{}] to [{}] for shard entry [{}]", shardEntry.shardId, actionName, masterNode.getId(), shardEntry);
             transportService.sendRequest(masterNode,
@@ -108,7 +111,7 @@ public class ShardStateAction extends AbstractComponent {
                     @Override
                     public void handleException(TransportException exp) {
                         if (isMasterChannelException(exp)) {
-                            waitForNewMasterAndRetry(actionName, observer, shardEntry, listener);
+                            waitForNewMasterAndRetry(actionName, observer, shardEntry, listener, changePredicate);
                         } else {
                             logger.warn((Supplier<?>) () -> new ParameterizedMessage("{} unexpected failure while sending request [{}] to [{}] for shard entry [{}]", shardEntry.shardId, actionName, masterNode, shardEntry), exp);
                             listener.onFailure(exp instanceof RemoteTransportException ? (Exception) (exp.getCause() instanceof Exception ? exp.getCause() : new ElasticsearchException(exp.getCause())) : exp);
@@ -162,20 +165,19 @@ public class ShardStateAction extends AbstractComponent {
 
     private void shardFailed(final ShardId shardId, String allocationId, long primaryTerm, final String message,
                              @Nullable final Exception failure, Listener listener, ClusterState currentState) {
-        ClusterStateObserver observer = new ClusterStateObserver(currentState, clusterService, null, logger, threadPool.getThreadContext());
         ShardEntry shardEntry = new ShardEntry(shardId, allocationId, primaryTerm, message, failure);
-        sendShardAction(SHARD_FAILED_ACTION_NAME, observer, shardEntry, listener);
+        sendShardAction(SHARD_FAILED_ACTION_NAME, currentState, shardEntry, listener);
     }
 
     // visible for testing
-    protected void waitForNewMasterAndRetry(String actionName, ClusterStateObserver observer, ShardEntry shardEntry, Listener listener) {
+    protected void waitForNewMasterAndRetry(String actionName, ClusterStateObserver observer, ShardEntry shardEntry, Listener listener, Predicate<ClusterState> changePredicate) {
         observer.waitForNextChange(new ClusterStateObserver.Listener() {
             @Override
             public void onNewClusterState(ClusterState state) {
                 if (logger.isTraceEnabled()) {
                     logger.trace("new cluster state [{}] after waiting for master election to fail shard entry [{}]", state, shardEntry);
                 }
-                sendShardAction(actionName, observer, shardEntry, listener);
+                sendShardAction(actionName, state, shardEntry, listener);
             }
 
             @Override
@@ -189,7 +191,7 @@ public class ShardStateAction extends AbstractComponent {
                 // we wait indefinitely for a new master
                 assert false;
             }
-        }, MasterNodeChangePredicate.build(observer.observedState()));
+        }, changePredicate);
     }
 
     private static class ShardFailedTransportHandler implements TransportRequestHandler<ShardEntry> {
@@ -354,9 +356,8 @@ public class ShardStateAction extends AbstractComponent {
         shardStarted(shardRouting, message, listener, clusterService.state());
     }
     public void shardStarted(final ShardRouting shardRouting, final String message, Listener listener, ClusterState currentState) {
-        ClusterStateObserver observer = new ClusterStateObserver(currentState, clusterService, null, logger, threadPool.getThreadContext());
         ShardEntry shardEntry = new ShardEntry(shardRouting.shardId(), shardRouting.allocationId().getId(), 0L, message, null);
-        sendShardAction(SHARD_STARTED_ACTION_NAME, observer, shardEntry, listener);
+        sendShardAction(SHARD_STARTED_ACTION_NAME, currentState, shardEntry, listener);
     }
 
     private static class ShardStartedTransportHandler implements TransportRequestHandler<ShardEntry> {

core/src/main/java/org/elasticsearch/cluster/metadata/AliasMetaData.java

@@ -22,12 +22,14 @@ package org.elasticsearch.cluster.metadata;
 import org.elasticsearch.ElasticsearchGenerationException;
 import org.elasticsearch.cluster.AbstractDiffable;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 
 import java.io.IOException;
@@ -225,14 +227,7 @@ public class AliasMetaData extends AbstractDiffable<AliasMetaData> {
                 this.filter = null;
                 return this;
             }
-            try {
-                try (XContentParser parser = XContentFactory.xContent(filter).createParser(filter)) {
-                    filter(parser.mapOrdered());
-                }
-                return this;
-            } catch (IOException e) {
-                throw new ElasticsearchGenerationException("Failed to generate [" + filter + "]", e);
-            }
+            return filter(XContentHelper.convertToMap(XContentFactory.xContent(filter), filter, true));
         }
 
         public Builder filter(Map<String, Object> filter) {
@@ -286,11 +281,7 @@ public class AliasMetaData extends AbstractDiffable<AliasMetaData> {
                 if (binary) {
                     builder.field("filter", aliasMetaData.filter.compressed());
                 } else {
-                    byte[] data = aliasMetaData.filter().uncompressed();
-                    try (XContentParser parser = XContentFactory.xContent(data).createParser(data)) {
-                        Map<String, Object> filter = parser.mapOrdered();
-                        builder.field("filter", filter);
-                    }
+                    builder.field("filter", XContentHelper.convertToMap(new BytesArray(aliasMetaData.filter().uncompressed()), true).v2());
                 }
             }
             if (aliasMetaData.indexRouting() != null) {

core/src/main/java/org/elasticsearch/cluster/metadata/AliasValidator.java

@@ -25,7 +25,9 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.index.query.QueryParseContext;
@@ -74,8 +76,8 @@ public class AliasValidator extends AbstractComponent {
     public void validateAliasStandalone(Alias alias) {
         validateAliasStandalone(alias.name(), alias.indexRouting());
         if (Strings.hasLength(alias.filter())) {
-            try (XContentParser parser = XContentFactory.xContent(alias.filter()).createParser(alias.filter())) {
-                parser.map();
+            try {
+                XContentHelper.convertToMap(XContentFactory.xContent(alias.filter()), alias.filter(), false);
             } catch (Exception e) {
                 throw new IllegalArgumentException("failed to parse filter for alias [" + alias.name() + "]", e);
             }
@@ -113,9 +115,10 @@ public class AliasValidator extends AbstractComponent {
      * provided {@link org.elasticsearch.index.query.QueryShardContext}
      * @throws IllegalArgumentException if the filter is not valid
      */
-    public void validateAliasFilter(String alias, String filter, QueryShardContext queryShardContext) {
+    public void validateAliasFilter(String alias, String filter, QueryShardContext queryShardContext,
+            NamedXContentRegistry xContentRegistry) {
         assert queryShardContext != null;
-        try (XContentParser parser = XContentFactory.xContent(filter).createParser(filter)) {
+        try (XContentParser parser = XContentFactory.xContent(filter).createParser(xContentRegistry, filter)) {
             validateAliasFilter(parser, queryShardContext);
         } catch (Exception e) {
             throw new IllegalArgumentException("failed to parse filter for alias [" + alias + "]", e);
@@ -127,9 +130,10 @@ public class AliasValidator extends AbstractComponent {
      * provided {@link org.elasticsearch.index.query.QueryShardContext}
      * @throws IllegalArgumentException if the filter is not valid
      */
-    public void validateAliasFilter(String alias, byte[] filter, QueryShardContext queryShardContext) {
+    public void validateAliasFilter(String alias, byte[] filter, QueryShardContext queryShardContext,
+            NamedXContentRegistry xContentRegistry) {
         assert queryShardContext != null;
-        try (XContentParser parser = XContentFactory.xContent(filter).createParser(filter)) {
+        try (XContentParser parser = XContentFactory.xContent(filter).createParser(xContentRegistry, filter)) {
             validateAliasFilter(parser, queryShardContext);
         } catch (Exception e) {
             throw new IllegalArgumentException("failed to parse filter for alias [" + alias + "]", e);

core/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java

@@ -23,6 +23,7 @@ import com.carrotsearch.hppc.LongArrayList;
 import com.carrotsearch.hppc.cursors.IntObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
+
 import org.elasticsearch.Version;
 import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.cluster.Diff;
@@ -34,6 +35,7 @@ import org.elasticsearch.cluster.node.DiscoveryNodeFilters;
 import org.elasticsearch.cluster.routing.allocation.IndexMetaDataUpdater;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.collect.ImmutableOpenIntMap;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.collect.MapBuilder;
@@ -48,6 +50,7 @@ import org.elasticsearch.common.xcontent.FromXContentBuilder;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.gateway.MetaDataStateFormat;
@@ -831,9 +834,7 @@ public class IndexMetaData implements Diffable<IndexMetaData>, FromXContentBuild
         }
 
         public Builder putMapping(String type, String source) throws IOException {
-            try (XContentParser parser = XContentFactory.xContent(source).createParser(source)) {
-                putMapping(new MappingMetaData(type, parser.mapOrdered()));
-            }
+            putMapping(new MappingMetaData(type, XContentHelper.convertToMap(XContentFactory.xContent(source), source, true)));
             return this;
         }
 
@@ -1047,11 +1048,7 @@ public class IndexMetaData implements Diffable<IndexMetaData>, FromXContentBuild
                 if (binary) {
                     builder.value(cursor.value.source().compressed());
                 } else {
-                    byte[] data = cursor.value.source().uncompressed();
-                    try (XContentParser parser = XContentFactory.xContent(data).createParser(data)) {
-                        Map<String, Object> mapping = parser.mapOrdered();
-                        builder.map(mapping);
-                    }
+                    builder.map(XContentHelper.convertToMap(new BytesArray(cursor.value.source().uncompressed()), true).v2());
                 }
             }
             builder.endArray();

core/src/main/java/org/elasticsearch/cluster/metadata/IndexTemplateMetaData.java

@@ -24,6 +24,7 @@ import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.AbstractDiffable;
 import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.compress.CompressedXContent;
@@ -37,6 +38,7 @@ import org.elasticsearch.common.util.set.Sets;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 
 import java.io.IOException;
@@ -395,10 +397,7 @@ public class IndexTemplateMetaData extends AbstractDiffable<IndexTemplateMetaDat
                 builder.startObject("mappings");
                 for (ObjectObjectCursor<String, CompressedXContent> cursor : indexTemplateMetaData.mappings()) {
                     byte[] mappingSource = cursor.value.uncompressed();
-                    Map<String, Object> mapping;
-                    try (XContentParser parser = XContentFactory.xContent(mappingSource).createParser(mappingSource)) {;
-                        mapping = parser.map();
-                    }
+                    Map<String, Object> mapping = XContentHelper.convertToMap(new BytesArray(mappingSource), false).v2();
                     if (mapping.size() == 1 && mapping.containsKey(cursor.key)) {
                         // the type name is the root value, reduce it
                         mapping = (Map<String, Object>) mapping.get(cursor.key);
@@ -411,10 +410,7 @@ public class IndexTemplateMetaData extends AbstractDiffable<IndexTemplateMetaDat
                 builder.startArray("mappings");
                 for (ObjectObjectCursor<String, CompressedXContent> cursor : indexTemplateMetaData.mappings()) {
                     byte[] data = cursor.value.uncompressed();
-                    try (XContentParser parser = XContentFactory.xContent(data).createParser(data)) {
-                        Map<String, Object> mapping = parser.mapOrdered();
-                        builder.map(mapping);
-                    }
+                    builder.map(XContentHelper.convertToMap(new BytesArray(data), true).v2());
                 }
                 builder.endArray();
             }

core/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java

@@ -27,7 +27,6 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
-import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.mapper.DateFieldMapper;
 import org.elasticsearch.index.mapper.DocumentMapper;
 
@@ -89,10 +88,7 @@ public class MappingMetaData extends AbstractDiffable<MappingMetaData> {
 
     public MappingMetaData(CompressedXContent mapping) throws IOException {
         this.source = mapping;
-        Map<String, Object> mappingMap;
-        try (XContentParser parser = XContentHelper.createParser(mapping.compressedReference())) {
-            mappingMap = parser.mapOrdered();
-        }
+        Map<String, Object> mappingMap = XContentHelper.convertToMap(mapping.compressedReference(), true).v2();
         if (mappingMap.size() != 1) {
             throw new IllegalStateException("Can't derive type from mapping, no root type: " + mapping.string());
         }

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -59,6 +59,7 @@ import org.elasticsearch.common.io.PathUtils;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.Index;
@@ -113,12 +114,14 @@ public class MetaDataCreateIndexService extends AbstractComponent {
     private final Environment env;
     private final IndexScopedSettings indexScopedSettings;
     private final ActiveShardsObserver activeShardsObserver;
+    private final NamedXContentRegistry xContentRegistry;
 
     @Inject
     public MetaDataCreateIndexService(Settings settings, ClusterService clusterService,
                                       IndicesService indicesService, AllocationService allocationService,
                                       AliasValidator aliasValidator, Environment env,
-                                      IndexScopedSettings indexScopedSettings, ThreadPool threadPool) {
+                                      IndexScopedSettings indexScopedSettings, ThreadPool threadPool,
+                                      NamedXContentRegistry xContentRegistry) {
         super(settings);
         this.clusterService = clusterService;
         this.indicesService = indicesService;
@@ -127,6 +130,7 @@ public class MetaDataCreateIndexService extends AbstractComponent {
         this.env = env;
         this.indexScopedSettings = indexScopedSettings;
         this.activeShardsObserver = new ActiveShardsObserver(settings, clusterService, threadPool);
+        this.xContentRegistry = xContentRegistry;
     }
 
     /**
@@ -248,7 +252,7 @@ public class MetaDataCreateIndexService extends AbstractComponent {
                             List<String> templateNames = new ArrayList<>();
 
                             for (Map.Entry<String, String> entry : request.mappings().entrySet()) {
-                                mappings.put(entry.getKey(), MapperService.parseMapping(entry.getValue()));
+                                mappings.put(entry.getKey(), MapperService.parseMapping(xContentRegistry, entry.getValue()));
                             }
 
                             for (Map.Entry<String, Custom> entry : request.customs().entrySet()) {
@@ -260,9 +264,10 @@ public class MetaDataCreateIndexService extends AbstractComponent {
                                 templateNames.add(template.getName());
                                 for (ObjectObjectCursor<String, CompressedXContent> cursor : template.mappings()) {
                                     if (mappings.containsKey(cursor.key)) {
-                                        XContentHelper.mergeDefaults(mappings.get(cursor.key), MapperService.parseMapping(cursor.value.string()));
+                                        XContentHelper.mergeDefaults(mappings.get(cursor.key),
+                                                MapperService.parseMapping(xContentRegistry, cursor.value.string()));
                                     } else {
-                                        mappings.put(cursor.key, MapperService.parseMapping(cursor.value.string()));
+                                        mappings.put(cursor.key, MapperService.parseMapping(xContentRegistry, cursor.value.string()));
                                     }
                                 }
                                 // handle custom
@@ -368,12 +373,13 @@ public class MetaDataCreateIndexService extends AbstractComponent {
                             final QueryShardContext queryShardContext = indexService.newQueryShardContext(0, null, () -> 0L);
                             for (Alias alias : request.aliases()) {
                                 if (Strings.hasLength(alias.filter())) {
-                                    aliasValidator.validateAliasFilter(alias.name(), alias.filter(), queryShardContext);
+                                    aliasValidator.validateAliasFilter(alias.name(), alias.filter(), queryShardContext, xContentRegistry);
                                 }
                             }
                             for (AliasMetaData aliasMetaData : templatesAliases.values()) {
                                 if (aliasMetaData.filter() != null) {
-                                    aliasValidator.validateAliasFilter(aliasMetaData.alias(), aliasMetaData.filter().uncompressed(), queryShardContext);
+                                    aliasValidator.validateAliasFilter(aliasMetaData.alias(), aliasMetaData.filter().uncompressed(),
+                                            queryShardContext, xContentRegistry);
                                 }
                             }
 

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexAliasesService.java

@@ -33,6 +33,7 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.IndexService;
@@ -64,18 +65,17 @@ public class MetaDataIndexAliasesService extends AbstractComponent {
 
     private final MetaDataDeleteIndexService deleteIndexService;
 
+    private final NamedXContentRegistry xContentRegistry;
+
     @Inject
-    public MetaDataIndexAliasesService(
-        Settings settings,
-        ClusterService clusterService,
-        IndicesService indicesService,
-        AliasValidator aliasValidator,
-        MetaDataDeleteIndexService deleteIndexService) {
+    public MetaDataIndexAliasesService(Settings settings, ClusterService clusterService, IndicesService indicesService,
+            AliasValidator aliasValidator, MetaDataDeleteIndexService deleteIndexService, NamedXContentRegistry xContentRegistry) {
         super(settings);
         this.clusterService = clusterService;
         this.indicesService = indicesService;
         this.aliasValidator = aliasValidator;
         this.deleteIndexService = deleteIndexService;
+        this.xContentRegistry = xContentRegistry;
     }
 
     public void indicesAliases(final IndicesAliasesClusterStateUpdateRequest request,
@@ -151,7 +151,8 @@ public class MetaDataIndexAliasesService extends AbstractComponent {
                         }
                         // the context is only used for validation so it's fine to pass fake values for the shard id and the current
                         // timestamp
-                        aliasValidator.validateAliasFilter(alias, filter, indexService.newQueryShardContext(0, null, () -> 0L));
+                        aliasValidator.validateAliasFilter(alias, filter, indexService.newQueryShardContext(0, null, () -> 0L),
+                                xContentRegistry);
                     }
                 };
                 changed |= action.apply(newAliasValidator, metadata, index);

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexTemplateService.java

@@ -35,6 +35,7 @@ import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.MapperParsingException;
@@ -65,18 +66,20 @@ public class MetaDataIndexTemplateService extends AbstractComponent {
     private final IndicesService indicesService;
     private final MetaDataCreateIndexService metaDataCreateIndexService;
     private final IndexScopedSettings indexScopedSettings;
+    private final NamedXContentRegistry xContentRegistry;
 
     @Inject
     public MetaDataIndexTemplateService(Settings settings, ClusterService clusterService,
                                         MetaDataCreateIndexService metaDataCreateIndexService,
                                         AliasValidator aliasValidator, IndicesService indicesService,
-                                        IndexScopedSettings indexScopedSettings) {
+                                        IndexScopedSettings indexScopedSettings, NamedXContentRegistry xContentRegistry) {
         super(settings);
         this.clusterService = clusterService;
         this.aliasValidator = aliasValidator;
         this.indicesService = indicesService;
         this.metaDataCreateIndexService = metaDataCreateIndexService;
         this.indexScopedSettings = indexScopedSettings;
+        this.xContentRegistry = xContentRegistry;
     }
 
     public void removeTemplates(final RemoveRequest request, final RemoveListener listener) {
@@ -165,7 +168,7 @@ public class MetaDataIndexTemplateService extends AbstractComponent {
                     throw new IllegalArgumentException("index_template [" + request.name + "] already exists");
                 }
 
-                validateAndAddTemplate(request, templateBuilder, indicesService);
+                validateAndAddTemplate(request, templateBuilder, indicesService, xContentRegistry);
 
                 for (Alias alias : request.aliases) {
                     AliasMetaData aliasMetaData = AliasMetaData.builder(alias.name()).filter(alias.filter())
@@ -190,7 +193,7 @@ public class MetaDataIndexTemplateService extends AbstractComponent {
     }
 
     private static void validateAndAddTemplate(final PutRequest request, IndexTemplateMetaData.Builder templateBuilder,
-            IndicesService indicesService) throws Exception {
+            IndicesService indicesService, NamedXContentRegistry xContentRegistry) throws Exception {
         Index createdIndex = null;
         final String temporaryIndexName = UUIDs.randomBase64UUID();
         try {
@@ -220,7 +223,7 @@ public class MetaDataIndexTemplateService extends AbstractComponent {
                 } catch (Exception e) {
                     throw new MapperParsingException("Failed to parse mapping [{}]: {}", e, entry.getKey(), e.getMessage());
                 }
-                mappingsForValidation.put(entry.getKey(), MapperService.parseMapping(entry.getValue()));
+                mappingsForValidation.put(entry.getKey(), MapperService.parseMapping(xContentRegistry, entry.getValue()));
             }
 
             dummyIndexService.mapperService().merge(mappingsForValidation, MergeReason.MAPPING_UPDATE, false);

core/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeService.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.AnalyzerScope;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -50,12 +51,15 @@ import java.util.Set;
  */
 public class MetaDataIndexUpgradeService extends AbstractComponent {
 
+    private final NamedXContentRegistry xContentRegistry;
     private final MapperRegistry mapperRegistry;
     private final IndexScopedSettings indexScopedSettings;
 
     @Inject
-    public MetaDataIndexUpgradeService(Settings settings, MapperRegistry mapperRegistry, IndexScopedSettings indexScopedSettings) {
+    public MetaDataIndexUpgradeService(Settings settings, NamedXContentRegistry xContentRegistry, MapperRegistry mapperRegistry,
+            IndexScopedSettings indexScopedSettings) {
         super(settings);
+        this.xContentRegistry = xContentRegistry;
         this.mapperRegistry = mapperRegistry;
         this.indexScopedSettings = indexScopedSettings;
     }
@@ -146,7 +150,8 @@ public class MetaDataIndexUpgradeService extends AbstractComponent {
                 }
             };
             try (IndexAnalyzers fakeIndexAnalzyers = new IndexAnalyzers(indexSettings, fakeDefault, fakeDefault, fakeDefault, analyzerMap)) {
-                MapperService mapperService = new MapperService(indexSettings, fakeIndexAnalzyers, similarityService, mapperRegistry, () -> null);
+                MapperService mapperService = new MapperService(indexSettings, fakeIndexAnalzyers, xContentRegistry, similarityService,
+                        mapperRegistry, () -> null);
                 mapperService.merge(indexMetaData, MapperService.MergeReason.MAPPING_RECOVERY, false);
             }
         } catch (Exception ex) {

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/AwarenessAllocationDecider.java

@@ -125,7 +125,7 @@ public class AwarenessAllocationDecider extends AllocationDecider {
     private Decision underCapacity(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation, boolean moveToNode) {
         if (awarenessAttributes.length == 0) {
             return allocation.decision(Decision.YES, NAME,
-                "allocation awareness is not enabled, set [%s] to enable it",
+                "allocation awareness is not enabled, set cluster setting [%s] to enable it",
                 CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.getKey());
         }
 
@@ -135,7 +135,7 @@ public class AwarenessAllocationDecider extends AllocationDecider {
             // the node the shard exists on must be associated with an awareness attribute
             if (!node.node().getAttributes().containsKey(awarenessAttribute)) {
                 return allocation.decision(Decision.NO, NAME,
-                    "node does not contain the awareness attribute [%s]; required attributes [%s=%s]",
+                    "node does not contain the awareness attribute [%s]; required attributes cluster setting [%s=%s]",
                     awarenessAttribute, CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.getKey(),
                     allocation.debugDecision() ? Strings.arrayToCommaDelimitedString(awarenessAttributes) : null);
             }

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/ClusterRebalanceAllocationDecider.java

@@ -120,13 +120,13 @@ public class ClusterRebalanceAllocationDecider extends AllocationDecider {
             // check if there are unassigned primaries.
             if ( allocation.routingNodes().hasUnassignedPrimaries() ) {
                 return allocation.decision(Decision.NO, NAME,
-                        "the cluster has unassigned primary shards and [%s] is set to [%s]",
+                        "the cluster has unassigned primary shards and cluster setting [%s] is set to [%s]",
                         CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE, type);
             }
             // check if there are initializing primaries that don't have a relocatingNodeId entry.
             if ( allocation.routingNodes().hasInactivePrimaries() ) {
                 return allocation.decision(Decision.NO, NAME,
-                        "the cluster has inactive primary shards and [%s] is set to [%s]",
+                        "the cluster has inactive primary shards and cluster setting [%s] is set to [%s]",
                         CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE, type);
             }
 
@@ -136,14 +136,14 @@ public class ClusterRebalanceAllocationDecider extends AllocationDecider {
             // check if there are unassigned shards.
             if (allocation.routingNodes().hasUnassignedShards() ) {
                 return allocation.decision(Decision.NO, NAME,
-                        "the cluster has unassigned shards and [%s] is set to [%s]",
+                        "the cluster has unassigned shards and cluster setting [%s] is set to [%s]",
                         CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE, type);
             }
             // in case all indices are assigned, are there initializing shards which
             // are not relocating?
             if ( allocation.routingNodes().hasInactiveShards() ) {
                 return allocation.decision(Decision.NO, NAME,
-                        "the cluster has inactive shards and [%s] is set to [%s]",
+                        "the cluster has inactive shards and cluster setting [%s] is set to [%s]",
                         CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE, type);
             }
         }

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/ConcurrentRebalanceAllocationDecider.java

@@ -67,7 +67,7 @@ public class ConcurrentRebalanceAllocationDecider extends AllocationDecider {
         int relocatingShards = allocation.routingNodes().getRelocatingShardCount();
         if (relocatingShards >= clusterConcurrentRebalance) {
             return allocation.decision(Decision.THROTTLE, NAME,
-                    "reached the limit of concurrently rebalancing shards [%d], [%s=%d]",
+                    "reached the limit of concurrently rebalancing shards [%d], cluster setting [%s=%d]",
                     relocatingShards,
                     CLUSTER_ROUTING_ALLOCATION_CLUSTER_CONCURRENT_REBALANCE_SETTING.getKey(),
                     clusterConcurrentRebalance);

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/DiskThresholdDecider.java

@@ -138,7 +138,8 @@ public class DiskThresholdDecider extends AllocationDecider {
                             diskThresholdSettings.getFreeBytesThresholdLow(), freeBytes, node.nodeId());
                 }
                 return allocation.decision(Decision.NO, NAME,
-                    "the node is above the low watermark [%s=%s], having less than the minimum required [%s] free space, actual free: [%s]",
+                    "the node is above the low watermark cluster setting [%s=%s], having less than the minimum required [%s] free " +
+                    "space, actual free: [%s]",
                     CLUSTER_ROUTING_ALLOCATION_LOW_DISK_WATERMARK_SETTING.getKey(),
                     diskThresholdSettings.getLowWatermarkRaw(),
                     diskThresholdSettings.getFreeBytesThresholdLow(), new ByteSizeValue(freeBytes));
@@ -162,8 +163,8 @@ public class DiskThresholdDecider extends AllocationDecider {
                             diskThresholdSettings.getFreeBytesThresholdHigh(), freeBytes, node.nodeId());
                 }
                 return allocation.decision(Decision.NO, NAME,
-                    "the node is above the high watermark [%s=%s], having less than the minimum required [%s] free space, " +
-                    "actual free: [%s]",
+                    "the node is above the high watermark cluster setting [%s=%s], having less than the minimum required [%s] free " +
+                    "space, actual free: [%s]",
                     CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                     diskThresholdSettings.getHighWatermarkRaw(),
                     diskThresholdSettings.getFreeBytesThresholdHigh(), new ByteSizeValue(freeBytes));
@@ -180,8 +181,8 @@ public class DiskThresholdDecider extends AllocationDecider {
                             Strings.format1Decimals(usedDiskPercentage, "%"), node.nodeId());
                 }
                 return allocation.decision(Decision.NO, NAME,
-                    "the node is above the low watermark [%s=%s], using more disk space than the maximum allowed [%s%%], " +
-                    "actual free: [%s%%]",
+                    "the node is above the low watermark cluster setting [%s=%s], using more disk space than the maximum allowed " +
+                    "[%s%%], actual free: [%s%%]",
                     CLUSTER_ROUTING_ALLOCATION_LOW_DISK_WATERMARK_SETTING.getKey(),
                     diskThresholdSettings.getLowWatermarkRaw(), usedDiskThresholdLow, freeDiskPercentage);
             } else if (freeDiskPercentage > diskThresholdSettings.getFreeDiskThresholdHigh()) {
@@ -206,8 +207,8 @@ public class DiskThresholdDecider extends AllocationDecider {
                             Strings.format1Decimals(freeDiskPercentage, "%"), node.nodeId());
                 }
                 return allocation.decision(Decision.NO, NAME,
-                    "the node is above the high watermark [%s=%s], using more disk space than the maximum allowed [%s%%], " +
-                    "actual free: [%s%%]",
+                    "the node is above the high watermark cluster setting [%s=%s], using more disk space than the maximum allowed " +
+                    "[%s%%], actual free: [%s%%]",
                     CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                     diskThresholdSettings.getHighWatermarkRaw(), usedDiskThresholdHigh, freeDiskPercentage);
             }
@@ -222,7 +223,7 @@ public class DiskThresholdDecider extends AllocationDecider {
                     "{} free bytes threshold ({} bytes free), preventing allocation",
                     node.nodeId(), diskThresholdSettings.getFreeBytesThresholdHigh(), freeBytesAfterShard);
             return allocation.decision(Decision.NO, NAME,
-                "allocating the shard to this node will bring the node above the high watermark [%s=%s] " +
+                "allocating the shard to this node will bring the node above the high watermark cluster setting [%s=%s] " +
                     "and cause it to have less than the minimum required [%s] of free space (free bytes after shard added: [%s])",
                 CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                 diskThresholdSettings.getHighWatermarkRaw(),
@@ -234,7 +235,7 @@ public class DiskThresholdDecider extends AllocationDecider {
                     node.nodeId(), Strings.format1Decimals(diskThresholdSettings.getFreeDiskThresholdHigh(), "%"),
                                                            Strings.format1Decimals(freeSpaceAfterShard, "%"));
             return allocation.decision(Decision.NO, NAME,
-                "allocating the shard to this node will bring the node above the high watermark [%s=%s] " +
+                "allocating the shard to this node will bring the node above the high watermark cluster setting [%s=%s] " +
                     "and cause it to use more disk space than the maximum allowed [%s%%] (free space after shard added: [%s%%])",
                 CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                 diskThresholdSettings.getHighWatermarkRaw(), usedDiskThresholdHigh, freeSpaceAfterShard);
@@ -279,7 +280,7 @@ public class DiskThresholdDecider extends AllocationDecider {
                         diskThresholdSettings.getFreeBytesThresholdHigh(), freeBytes, node.nodeId());
             }
             return allocation.decision(Decision.NO, NAME,
-                "the shard cannot remain on this node because it is above the high watermark [%s=%s] " +
+                "the shard cannot remain on this node because it is above the high watermark cluster setting [%s=%s] " +
                     "and there is less than the required [%s] free space on node, actual free: [%s]",
                 CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                 diskThresholdSettings.getHighWatermarkRaw(),
@@ -291,7 +292,7 @@ public class DiskThresholdDecider extends AllocationDecider {
                         diskThresholdSettings.getFreeDiskThresholdHigh(), freeDiskPercentage, node.nodeId());
             }
             return allocation.decision(Decision.NO, NAME,
-                "the shard cannot remain on this node because it is above the high watermark [%s=%s] " +
+                "the shard cannot remain on this node because it is above the high watermark cluster setting [%s=%s] " +
                     "and there is less than the required [%s%%] free disk on node, actual free: [%s%%]",
                 CLUSTER_ROUTING_ALLOCATION_HIGH_DISK_WATERMARK_SETTING.getKey(),
                 diskThresholdSettings.getHighWatermarkRaw(),

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/EnableAllocationDecider.java

@@ -189,10 +189,12 @@ public class EnableAllocationDecider extends AllocationDecider {
     }
 
     private static String setting(Rebalance rebalance, boolean usedIndexSetting) {
-        StringBuilder buf = new StringBuilder("[");
+        StringBuilder buf = new StringBuilder();
         if (usedIndexSetting) {
+            buf.append("index setting [");
             buf.append(INDEX_ROUTING_REBALANCE_ENABLE_SETTING.getKey());
         } else {
+            buf.append("cluster setting [");
             buf.append(CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey());
         }
         buf.append("=").append(rebalance.toString().toLowerCase(Locale.ROOT)).append("]");

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/FilterAllocationDecider.java

@@ -141,19 +141,19 @@ public class FilterAllocationDecider extends AllocationDecider {
     private Decision shouldIndexFilter(IndexMetaData indexMd, RoutingNode node, RoutingAllocation allocation) {
         if (indexMd.requireFilters() != null) {
             if (!indexMd.requireFilters().match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node does not match [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node does not match index setting [%s] filters [%s]",
                     IndexMetaData.INDEX_ROUTING_REQUIRE_GROUP_PREFIX, indexMd.requireFilters());
             }
         }
         if (indexMd.includeFilters() != null) {
             if (!indexMd.includeFilters().match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node does not match [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node does not match index setting [%s] filters [%s]",
                     IndexMetaData.INDEX_ROUTING_INCLUDE_GROUP_PREFIX, indexMd.includeFilters());
             }
         }
         if (indexMd.excludeFilters() != null) {
             if (indexMd.excludeFilters().match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node matches [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node matches index setting [%s] filters [%s]",
                     IndexMetaData.INDEX_ROUTING_EXCLUDE_GROUP_SETTING.getKey(), indexMd.excludeFilters());
             }
         }
@@ -163,19 +163,19 @@ public class FilterAllocationDecider extends AllocationDecider {
     private Decision shouldClusterFilter(RoutingNode node, RoutingAllocation allocation) {
         if (clusterRequireFilters != null) {
             if (!clusterRequireFilters.match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node does not match [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node does not match cluster setting [%s] filters [%s]",
                     CLUSTER_ROUTING_REQUIRE_GROUP_PREFIX, clusterRequireFilters);
             }
         }
         if (clusterIncludeFilters != null) {
             if (!clusterIncludeFilters.match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node does not [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node does not cluster setting [%s] filters [%s]",
                     CLUSTER_ROUTING_INCLUDE_GROUP_PREFIX, clusterIncludeFilters);
             }
         }
         if (clusterExcludeFilters != null) {
             if (clusterExcludeFilters.match(node.node())) {
-                return allocation.decision(Decision.NO, NAME, "node matches [%s] filters [%s]",
+                return allocation.decision(Decision.NO, NAME, "node matches cluster setting [%s] filters [%s]",
                     CLUSTER_ROUTING_EXCLUDE_GROUP_PREFIX, clusterExcludeFilters);
             }
         }

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/SameShardAllocationDecider.java

@@ -88,7 +88,8 @@ public class SameShardAllocationDecider extends AllocationDecider {
                             String host = checkNodeOnSameHostAddress ? node.node().getHostAddress() : node.node().getHostName();
                             return allocation.decision(Decision.NO, NAME,
                                 "the shard cannot be allocated on host %s [%s], where it already exists on node [%s]; " +
-                                    "set [%s] to false to allow multiple nodes on the same host to hold the same shard copies",
+                                    "set cluster setting [%s] to false to allow multiple nodes on the same host to hold the same " +
+                                    "shard copies",
                                 hostType, host, node.nodeId(), CLUSTER_ROUTING_ALLOCATION_SAME_HOST_SETTING.getKey());
                         }
                     }

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/ShardsLimitAllocationDecider.java

@@ -122,12 +122,12 @@ public class ShardsLimitAllocationDecider extends AllocationDecider {
 
         if (clusterShardLimit > 0 && decider.test(nodeShardCount, clusterShardLimit)) {
             return allocation.decision(Decision.NO, NAME,
-                "too many shards [%d] allocated to this node, [%s=%d]",
+                "too many shards [%d] allocated to this node, cluster setting [%s=%d]",
                 nodeShardCount, CLUSTER_TOTAL_SHARDS_PER_NODE_SETTING.getKey(), clusterShardLimit);
         }
         if (indexShardLimit > 0 && decider.test(indexShardCount, indexShardLimit)) {
             return allocation.decision(Decision.NO, NAME,
-                "too many shards [%d] allocated to this node for index [%s], [%s=%d]",
+                "too many shards [%d] allocated to this node for index [%s], index setting [%s=%d]",
                 indexShardCount, shardRouting.getIndexName(), INDEX_TOTAL_SHARDS_PER_NODE_SETTING.getKey(), indexShardLimit);
         }
         return allocation.decision(Decision.YES, NAME,
@@ -157,7 +157,7 @@ public class ShardsLimitAllocationDecider extends AllocationDecider {
         }
         if (clusterShardLimit >= 0 && nodeShardCount >= clusterShardLimit) {
             return allocation.decision(Decision.NO, NAME,
-                "too many shards [%d] allocated to this node, [%s=%d]",
+                "too many shards [%d] allocated to this node, cluster setting [%s=%d]",
                 nodeShardCount, CLUSTER_TOTAL_SHARDS_PER_NODE_SETTING.getKey(), clusterShardLimit);
         }
         return allocation.decision(Decision.YES, NAME,

core/src/main/java/org/elasticsearch/cluster/routing/allocation/decider/ThrottlingAllocationDecider.java

@@ -126,7 +126,8 @@ public class ThrottlingAllocationDecider extends AllocationDecider {
             }
             if (primariesInRecovery >= primariesInitialRecoveries) {
                 // TODO: Should index creation not be throttled for primary shards?
-                return allocation.decision(THROTTLE, NAME, "reached the limit of ongoing initial primary recoveries [%d], [%s=%d]",
+                return allocation.decision(THROTTLE, NAME,
+                    "reached the limit of ongoing initial primary recoveries [%d], cluster setting [%s=%d]",
                     primariesInRecovery, CLUSTER_ROUTING_ALLOCATION_NODE_INITIAL_PRIMARIES_RECOVERIES_SETTING.getKey(),
                     primariesInitialRecoveries);
             } else {
@@ -140,7 +141,7 @@ public class ThrottlingAllocationDecider extends AllocationDecider {
             int currentInRecoveries = allocation.routingNodes().getIncomingRecoveries(node.nodeId());
             if (currentInRecoveries >= concurrentIncomingRecoveries) {
                 return allocation.decision(THROTTLE, NAME,
-                    "reached the limit of incoming shard recoveries [%d], [%s=%d] (can also be set via [%s])",
+                    "reached the limit of incoming shard recoveries [%d], cluster setting [%s=%d] (can also be set via [%s])",
                     currentInRecoveries, CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_INCOMING_RECOVERIES_SETTING.getKey(),
                     concurrentIncomingRecoveries,
                     CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_RECOVERIES_SETTING.getKey());
@@ -154,7 +155,7 @@ public class ThrottlingAllocationDecider extends AllocationDecider {
                 if (primaryNodeOutRecoveries >= concurrentOutgoingRecoveries) {
                     return allocation.decision(THROTTLE, NAME,
                         "reached the limit of outgoing shard recoveries [%d] on the node [%s] which holds the primary, " +
-                        "[%s=%d] (can also be set via [%s])",
+                        "cluster setting [%s=%d] (can also be set via [%s])",
                         primaryNodeOutRecoveries, node.nodeId(),
                         CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_OUTGOING_RECOVERIES_SETTING.getKey(),
                         concurrentOutgoingRecoveries,

core/src/main/java/org/elasticsearch/common/ParseField.java

@@ -101,14 +101,10 @@ public class ParseField {
     /**
      * @param fieldName
      *            the field name to match against this {@link ParseField}
-     * @param strict
-     *            if true an exception will be thrown if a deprecated field name
-     *            is given. If false the deprecated name will be matched but a
-     *            message will also be logged to the {@link DeprecationLogger}
      * @return true if <code>fieldName</code> matches any of the acceptable
      *         names for this {@link ParseField}.
      */
-    boolean match(String fieldName, boolean strict) {
+    public boolean match(String fieldName) {
         Objects.requireNonNull(fieldName, "fieldName cannot be null");
         // if this parse field has not been completely deprecated then try to
         // match the preferred name
@@ -128,11 +124,7 @@ public class ParseField {
                     // message to indicate what should be used instead
                     msg = "Deprecated field [" + fieldName + "] used, replaced by [" + allReplacedWith + "]";
                 }
-                if (strict) {
-                    throw new IllegalArgumentException(msg);
-                } else {
-                    DEPRECATION_LOGGER.deprecated(msg);
-                }
+                DEPRECATION_LOGGER.deprecated(msg);
                 return true;
             }
         }

core/src/main/java/org/elasticsearch/common/ParseFieldMatcher.java

@@ -22,38 +22,29 @@ package org.elasticsearch.common;
 import org.elasticsearch.common.settings.Settings;
 
 /**
- * Matcher to use in combination with {@link ParseField} while parsing requests. Matches a {@link ParseField}
- * against a field name and throw deprecation exception depending on the current value of the {@link #PARSE_STRICT} setting.
+ * Matcher to use in combination with {@link ParseField} while parsing requests.
+ *
+ * @deprecated This class used to be useful to parse in strict mode and emit errors rather than deprecation warnings. Now that we return
+ * warnings as response headers all the time, it is no longer useful and will soon be removed. The removal is in progress and there is
+ * already no strict mode in fact. Use {@link ParseField} directly.
  */
+@Deprecated
 public class ParseFieldMatcher {
-    public static final String PARSE_STRICT = "index.query.parse.strict";
-    public static final ParseFieldMatcher EMPTY = new ParseFieldMatcher(false);
-    public static final ParseFieldMatcher STRICT = new ParseFieldMatcher(true);
-
-    private final boolean strict;
+    public static final ParseFieldMatcher EMPTY = new ParseFieldMatcher(Settings.EMPTY);
+    public static final ParseFieldMatcher STRICT = new ParseFieldMatcher(Settings.EMPTY);
 
     public ParseFieldMatcher(Settings settings) {
-        this(settings.getAsBoolean(PARSE_STRICT, false));
-    }
-
-    public ParseFieldMatcher(boolean strict) {
-        this.strict = strict;
-    }
-
-    /** Should deprecated settings be rejected? */
-    public boolean isStrict() {
-        return strict;
+        //we don't do anything with the settings argument, this whole class will be soon removed
     }
 
     /**
-     * Matches a {@link ParseField} against a field name, and throws deprecation exception depending on the current
-     * value of the {@link #PARSE_STRICT} setting.
+     * Matches a {@link ParseField} against a field name,
      * @param fieldName the field name found in the request while parsing
      * @param parseField the parse field that we are looking for
      * @throws IllegalArgumentException whenever we are in strict mode and the request contained a deprecated field
      * @return true whenever the parse field that we are looking for was found, false otherwise
      */
     public boolean match(String fieldName, ParseField parseField) {
-        return parseField.match(fieldName, strict);
+        return parseField.match(fieldName);
     }
 }

core/src/main/java/org/elasticsearch/common/logging/DeprecationLogger.java

@@ -21,7 +21,6 @@ package org.elasticsearch.common.logging;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.elasticsearch.common.SuppressLoggerChecks;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 
@@ -42,7 +41,7 @@ public class DeprecationLogger {
      *
      * https://tools.ietf.org/html/rfc7234#section-5.5
      */
-    public static final String DEPRECATION_HEADER = "Warning";
+    public static final String WARNING_HEADER = "Warning";
 
     /**
      * This is set once by the {@code Node} constructor, but it uses {@link CopyOnWriteArraySet} to ensure that tests can run in parallel.
@@ -128,7 +127,7 @@ public class DeprecationLogger {
 
             while (iterator.hasNext()) {
                 try {
-                    iterator.next().addResponseHeader(DEPRECATION_HEADER, formattedMessage);
+                    iterator.next().addResponseHeader(WARNING_HEADER, formattedMessage);
                 } catch (IllegalStateException e) {
                     // ignored; it should be removed shortly
                 }

core/src/main/java/org/elasticsearch/common/network/NetworkModule.java

@@ -35,6 +35,7 @@ import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.BigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.http.HttpServerTransport;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.plugins.NetworkPlugin;
@@ -107,13 +108,14 @@ public final class NetworkModule {
                          BigArrays bigArrays,
                          CircuitBreakerService circuitBreakerService,
                          NamedWriteableRegistry namedWriteableRegistry,
+                         NamedXContentRegistry xContentRegistry,
                          NetworkService networkService) {
         this.settings = settings;
         this.transportClient = transportClient;
         for (NetworkPlugin plugin : plugins) {
             if (transportClient == false && HTTP_ENABLED.get(settings)) {
                 Map<String, Supplier<HttpServerTransport>> httpTransportFactory = plugin.getHttpTransports(settings, threadPool, bigArrays,
-                    circuitBreakerService, namedWriteableRegistry, networkService);
+                    circuitBreakerService, namedWriteableRegistry, xContentRegistry, networkService);
                 for (Map.Entry<String, Supplier<HttpServerTransport>> entry : httpTransportFactory.entrySet()) {
                     registerHttpTransport(entry.getKey(), entry.getValue());
                 }

core/src/main/java/org/elasticsearch/common/settings/Setting.java

@@ -32,6 +32,7 @@ import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.unit.MemorySizeValue;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -702,7 +703,8 @@ public class Setting<T> extends ToXContentToBytes {
     }
 
     private static List<String> parseableStringToList(String parsableString) {
-        try (XContentParser xContentParser = XContentType.JSON.xContent().createParser(parsableString)) {
+        // EMPTY is safe here because we never call namedObject
+        try (XContentParser xContentParser = XContentType.JSON.xContent().createParser(NamedXContentRegistry.EMPTY, parsableString)) {
             XContentParser.Token token = xContentParser.nextToken();
             if (token != XContentParser.Token.START_ARRAY) {
                 throw new IllegalArgumentException("expected START_ARRAY but got " + token);

core/src/main/java/org/elasticsearch/common/settings/loader/XContentSettingsLoader.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.common.settings.loader;
 
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
@@ -46,14 +47,16 @@ public abstract class XContentSettingsLoader implements SettingsLoader {
 
     @Override
     public Map<String, String> load(String source) throws IOException {
-        try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(source)) {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(NamedXContentRegistry.EMPTY, source)) {
             return load(parser);
         }
     }
 
     @Override
     public Map<String, String> load(byte[] source) throws IOException {
-        try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(source)) {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = XContentFactory.xContent(contentType()).createParser(NamedXContentRegistry.EMPTY, source)) {
             return load(parser);
         }
     }

core/src/main/java/org/elasticsearch/common/text/Text.java

@@ -100,7 +100,10 @@ public final class Text implements Comparable<Text> {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == null) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
             return false;
         }
         return bytes().equals(((Text) obj).bytes());

core/src/main/java/org/elasticsearch/common/xcontent/NamedXContentRegistry.java

@@ -0,0 +1,211 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.common.xcontent;
+
+import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.unmodifiableMap;
+import static java.util.Objects.requireNonNull;
+
+public class NamedXContentRegistry {
+    /**
+     * The empty {@link NamedXContentRegistry} for use when you are sure that you aren't going to call
+     * {@link XContentParser#namedObject(Class, String, Object)}. Be *very* careful with this singleton because a parser using it will fail
+     * every call to {@linkplain XContentParser#namedObject(Class, String, Object)}. Every non-test usage really should be checked thorowly
+     * and marked with a comment about how it was checked. That way anyone that sees code that uses it knows that it is potentially
+     * dangerous.
+     */
+    public static final NamedXContentRegistry EMPTY = new NamedXContentRegistry(emptyList());
+
+    /**
+     * Parses an object with the type T from parser.
+     */
+    public interface FromXContent<T> {
+        /**
+         * Parses an object with the type T from parser.
+         */
+        T fromXContent(XContentParser parser) throws IOException;
+    }
+
+    /**
+     * Parses an object with the type T from parser.
+     * @deprecated prefer {@link FromXContent} if possible
+     */
+    @Deprecated
+    public interface FromXContentWithContext<T> {
+        T fromXContent(XContentParser parser, Object context) throws IOException;
+    }
+
+    /**
+     * An entry in the {@linkplain NamedXContentRegistry} containing the name of the object and the parser that can parse it.
+     */
+    public static class Entry {
+        /** The class that this entry can read. */
+        public final Class<?> categoryClass;
+
+        /** A name for the entry which is unique within the {@link #categoryClass}. */
+        public final ParseField name;
+
+        /** A parser capability of parser the entry's class. */
+        private final FromXContentWithContext<?> parser;
+
+        /** Creates a new entry which can be stored by the registry. */
+        public <T> Entry(Class<T> categoryClass, ParseField name, FromXContent<? extends T> parser) {
+            this.categoryClass = Objects.requireNonNull(categoryClass);
+            this.name = Objects.requireNonNull(name);
+            this.parser = Objects.requireNonNull((p, c) -> parser.fromXContent(p));
+        }
+        /**
+         * Creates a new entry which can be stored by the registry.
+         * @deprecated prefer {@link Entry#Entry(Class, ParseField, FromXContent)}. Contexts will be removed when possible
+         */
+        @Deprecated
+        public <T> Entry(Class<T> categoryClass, ParseField name, FromXContentWithContext<? extends T> parser) {
+            this.categoryClass = Objects.requireNonNull(categoryClass);
+            this.name = Objects.requireNonNull(name);
+            this.parser = Objects.requireNonNull(parser);
+        }
+    }
+
+    private final Map<Class<?>, Map<String, Entry>> registry;
+
+    public NamedXContentRegistry(List<Entry> entries) {
+        if (entries.isEmpty()) {
+            registry = emptyMap();
+            return;
+        }
+        entries = new ArrayList<>(entries);
+        entries.sort((e1, e2) -> e1.categoryClass.getName().compareTo(e2.categoryClass.getName()));
+
+        Map<Class<?>, Map<String, Entry>> registry = new HashMap<>();
+        Map<String, Entry> parsers = null;
+        Class<?> currentCategory = null;
+        for (Entry entry : entries) {
+            if (currentCategory != entry.categoryClass) {
+                if (currentCategory != null) {
+                    // we've seen the last of this category, put it into the big map
+                    registry.put(currentCategory, unmodifiableMap(parsers));
+                }
+                parsers = new HashMap<>();
+                currentCategory = entry.categoryClass;
+            }
+
+            for (String name : entry.name.getAllNamesIncludedDeprecated()) {
+                Object old = parsers.put(name, entry);
+                if (old != null) {
+                    throw new IllegalArgumentException("NamedXContent [" + currentCategory.getName() + "][" + entry.name + "]" +
+                        " is already registered for [" + old.getClass().getName() + "]," +
+                        " cannot register [" + entry.parser.getClass().getName() + "]");
+                }
+            }
+        }
+        // handle the last category
+        registry.put(currentCategory, unmodifiableMap(parsers));
+
+        this.registry = unmodifiableMap(registry);
+    }
+
+    /**
+     * Parse a named object, throwing an exception if the parser isn't found. Throws an {@link ElasticsearchException} if the
+     * {@code categoryClass} isn't registered because this is almost always a bug. Throws a {@link UnknownNamedObjectException} if the
+     * {@code categoryClass} is registered but the {@code name} isn't.
+     */
+    public <T, C> T parseNamedObject(Class<T> categoryClass, String name, XContentParser parser, C context) throws IOException {
+        Map<String, Entry> parsers = registry.get(categoryClass);
+        if (parsers == null) {
+            if (registry.isEmpty()) {
+                // The "empty" registry will never work so we throw a better exception as a hint.
+                throw new ElasticsearchException("namedObject is not supported for this parser");
+            }
+            throw new ElasticsearchException("Unknown namedObject category [" + categoryClass.getName() + "]");
+        }
+        Entry entry = parsers.get(name);
+        if (entry == null) {
+            throw new UnknownNamedObjectException(parser.getTokenLocation(), categoryClass, name);
+        }
+        if (false == entry.name.match(name)) {
+            /* Note that this shouldn't happen because we already looked up the entry using the names but we need to call `match` anyway
+             * because it is responsible for logging deprecation warnings. */
+            throw new ParsingException(parser.getTokenLocation(),
+                    "Unknown " + categoryClass.getSimpleName() + " [" + name + "]: Parser didn't match");
+        }
+        return categoryClass.cast(entry.parser.fromXContent(parser, context));
+    }
+
+    /**
+     * Thrown when {@link NamedXContentRegistry#parseNamedObject(Class, String, XContentParser, Object)} is called with an unregistered
+     * name. When this bubbles up to the rest layer it is converted into a response with {@code 400 BAD REQUEST} status.
+     */
+    public static class UnknownNamedObjectException extends ParsingException {
+        private final String categoryClass;
+        private final String name;
+
+        public UnknownNamedObjectException(XContentLocation contentLocation, Class<?> categoryClass,
+                String name) {
+            super(contentLocation, "Unknown " + categoryClass.getSimpleName() + " [" + name + "]");
+            this.categoryClass = requireNonNull(categoryClass, "categoryClass is required").getName();
+            this.name = requireNonNull(name, "name is required");
+        }
+
+        /**
+         * Read from a stream.
+         */
+        public UnknownNamedObjectException(StreamInput in) throws IOException {
+            super(in);
+            categoryClass = in.readString();
+            name = in.readString();
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            super.writeTo(out);
+            out.writeString(categoryClass);
+            out.writeString(name);
+        }
+
+        /**
+         * Category class that was missing a parser. This is a String instead of a class because the class might not be on the classpath
+         * of all nodes or it might be exclusive to a plugin or something.
+         */
+        public String getCategoryClass() {
+            return categoryClass;
+        }
+
+        /**
+         * Name of the missing parser.
+         */
+        public String getName() {
+            return name;
+        }
+    }
+}

core/src/main/java/org/elasticsearch/common/xcontent/XContent.java

@@ -83,31 +83,31 @@ public interface XContent {
     /**
      * Creates a parser over the provided string content.
      */
-    XContentParser createParser(String content) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, String content) throws IOException;
 
     /**
      * Creates a parser over the provided input stream.
      */
-    XContentParser createParser(InputStream is) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, InputStream is) throws IOException;
 
     /**
      * Creates a parser over the provided bytes.
      */
-    XContentParser createParser(byte[] data) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data) throws IOException;
 
     /**
      * Creates a parser over the provided bytes.
      */
-    XContentParser createParser(byte[] data, int offset, int length) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data, int offset, int length) throws IOException;
 
     /**
      * Creates a parser over the provided bytes.
      */
-    XContentParser createParser(BytesReference bytes) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException;
 
     /**
      * Creates a parser over the provided reader.
      */
-    XContentParser createParser(Reader reader) throws IOException;
+    XContentParser createParser(NamedXContentRegistry xContentRegistry, Reader reader) throws IOException;
 
 }

core/src/main/java/org/elasticsearch/common/xcontent/XContentHelper.java

@@ -41,7 +41,7 @@ import static org.elasticsearch.common.xcontent.ToXContent.EMPTY_PARAMS;
 @SuppressWarnings("unchecked")
 public class XContentHelper {
 
-    public static XContentParser createParser(BytesReference bytes) throws IOException {
+    public static XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException {
         Compressor compressor = CompressorFactory.compressor(bytes);
         if (compressor != null) {
             InputStream compressedInput = compressor.streamInput(bytes.streamInput());
@@ -49,13 +49,14 @@ public class XContentHelper {
                 compressedInput = new BufferedInputStream(compressedInput);
             }
             XContentType contentType = XContentFactory.xContentType(compressedInput);
-            return XContentFactory.xContent(contentType).createParser(compressedInput);
+            return XContentFactory.xContent(contentType).createParser(xContentRegistry, compressedInput);
         } else {
-            return XContentFactory.xContent(bytes).createParser(bytes.streamInput());
+            return XContentFactory.xContent(bytes).createParser(xContentRegistry, bytes.streamInput());
         }
     }
 
-    public static Tuple<XContentType, Map<String, Object>> convertToMap(BytesReference bytes, boolean ordered) throws ElasticsearchParseException {
+    public static Tuple<XContentType, Map<String, Object>> convertToMap(BytesReference bytes, boolean ordered)
+            throws ElasticsearchParseException {
         try {
             XContentType contentType;
             InputStream input;
@@ -71,13 +72,34 @@ public class XContentHelper {
                 contentType = XContentFactory.xContentType(bytes);
                 input = bytes.streamInput();
             }
-            try (XContentParser parser = XContentFactory.xContent(contentType).createParser(input)) {
-                if (ordered) {
-                    return Tuple.tuple(contentType, parser.mapOrdered());
-                } else {
-                    return Tuple.tuple(contentType, parser.map());
-                }
-            }
+            return new Tuple<>(contentType, convertToMap(XContentFactory.xContent(contentType), input, ordered));
+        } catch (IOException e) {
+            throw new ElasticsearchParseException("Failed to parse content to map", e);
+        }
+    }
+
+    /**
+     * Convert a string in some {@link XContent} format to a {@link Map}. Throws an {@link ElasticsearchParseException} if there is any
+     * error.
+     */
+    public static Map<String, Object> convertToMap(XContent xContent, String string, boolean ordered) throws ElasticsearchParseException {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = xContent.createParser(NamedXContentRegistry.EMPTY, string)) {
+            return ordered ? parser.mapOrdered() : parser.map();
+        } catch (IOException e) {
+            throw new ElasticsearchParseException("Failed to parse content to map", e);
+        }
+    }
+
+    /**
+     * Convert a string in some {@link XContent} format to a {@link Map}. Throws an {@link ElasticsearchParseException} if there is any
+     * error. Note that unlike {@link #convertToMap(BytesReference, boolean)}, this doesn't automatically uncompress the input.
+     */
+    public static Map<String, Object> convertToMap(XContent xContent, InputStream input, boolean ordered)
+            throws ElasticsearchParseException {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = xContent.createParser(NamedXContentRegistry.EMPTY, input)) {
+            return ordered ? parser.mapOrdered() : parser.map();
         } catch (IOException e) {
             throw new ElasticsearchParseException("Failed to parse content to map", e);
         }
@@ -92,7 +114,9 @@ public class XContentHelper {
         if (xContentType == XContentType.JSON && !reformatJson) {
             return bytes.utf8ToString();
         }
-        try (XContentParser parser = XContentFactory.xContent(xContentType).createParser(bytes.streamInput())) {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = XContentFactory.xContent(xContentType).createParser(NamedXContentRegistry.EMPTY,
+                bytes.streamInput())) {
             parser.nextToken();
             XContentBuilder builder = XContentFactory.jsonBuilder();
             if (prettyPrint) {
@@ -191,7 +215,6 @@ public class XContentHelper {
      * Merges the defaults provided as the second parameter into the content of the first. Only does recursive merge
      * for inner maps.
      */
-    @SuppressWarnings({"unchecked"})
     public static void mergeDefaults(Map<String, Object> content, Map<String, Object> defaults) {
         for (Map.Entry<String, Object> defaultEntry : defaults.entrySet()) {
             if (!content.containsKey(defaultEntry.getKey())) {
@@ -255,33 +278,36 @@ public class XContentHelper {
         return true;
     }
 
-    public static void copyCurrentStructure(XContentGenerator generator, XContentParser parser) throws IOException {
+    /**
+     * Low level implementation detail of {@link XContentGenerator#copyCurrentStructure(XContentParser)}.
+     */
+    public static void copyCurrentStructure(XContentGenerator destination, XContentParser parser) throws IOException {
         XContentParser.Token token = parser.currentToken();
 
         // Let's handle field-name separately first
         if (token == XContentParser.Token.FIELD_NAME) {
-            generator.writeFieldName(parser.currentName());
+            destination.writeFieldName(parser.currentName());
             token = parser.nextToken();
             // fall-through to copy the associated value
         }
 
         switch (token) {
             case START_ARRAY:
-                generator.writeStartArray();
+                destination.writeStartArray();
                 while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
-                    copyCurrentStructure(generator, parser);
+                    copyCurrentStructure(destination, parser);
                 }
-                generator.writeEndArray();
+                destination.writeEndArray();
                 break;
             case START_OBJECT:
-                generator.writeStartObject();
+                destination.writeStartObject();
                 while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
-                    copyCurrentStructure(generator, parser);
+                    copyCurrentStructure(destination, parser);
                 }
-                generator.writeEndObject();
+                destination.writeEndObject();
                 break;
             default: // others are simple:
-                copyCurrentEvent(generator, parser);
+                copyCurrentEvent(destination, parser);
         }
     }
 
@@ -349,4 +375,22 @@ public class XContentHelper {
             builder.rawField(field, source);
         }
     }
+
+    /**
+     * Returns the bytes that represent the XContent output of the provided {@link ToXContent} object, using the provided
+     * {@link XContentType}. Wraps the output into a new anonymous object depending on the value of the wrapInObject argument.
+     */
+    public static BytesReference toXContent(ToXContent toXContent, XContentType xContentType, boolean wrapInObject) throws IOException {
+        try (XContentBuilder builder = XContentBuilder.builder(xContentType.xContent())) {
+            if (wrapInObject) {
+                builder.startObject();
+            }
+            toXContent.toXContent(builder, ToXContent.EMPTY_PARAMS);
+            if (wrapInObject) {
+                builder.endObject();
+            }
+            return builder.bytes();
+        }
+    }
+
 }

core/src/main/java/org/elasticsearch/common/xcontent/XContentParser.java

@@ -249,5 +249,16 @@ public interface XContentParser extends Releasable {
      */
     XContentLocation getTokenLocation();
 
+    // TODO remove context entirely when it isn't needed
+    /**
+     * Parse an object by name.
+     */
+    <T> T namedObject(Class<T> categoryClass, String name, Object context) throws IOException;
+
+    /**
+     * The registry used to resolve {@link #namedObject(Class, String, Object)}. Use this when building a sub-parser from this parser.
+     */
+    NamedXContentRegistry getXContentRegistry();
+
     boolean isClosed();
 }

core/src/main/java/org/elasticsearch/common/xcontent/XContentParserUtils.java

@@ -22,7 +22,6 @@ package org.elasticsearch.common.xcontent;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 
-import java.io.IOException;
 import java.util.Locale;
 import java.util.function.Supplier;
 
@@ -35,34 +34,6 @@ public final class XContentParserUtils {
     private XContentParserUtils() {
     }
 
-    /**
-     * Makes sure that current token is of type {@link XContentParser.Token#FIELD_NAME}
-     *
-     * @return the token
-     * @throws ParsingException if the token is not of type {@link XContentParser.Token#FIELD_NAME}
-     */
-    public static Token ensureFieldName(Token token, Supplier<XContentLocation> location) throws IOException {
-        return ensureType(Token.FIELD_NAME, token, location);
-    }
-
-    /**
-     * Makes sure that current token is of type {@link XContentParser.Token#FIELD_NAME} and the the field name is equal to the provided one
-     *
-     * @return the token
-     * @throws ParsingException if the token is not of type {@link XContentParser.Token#FIELD_NAME} or is not equal to the given
-     *                          field name
-     */
-    public static Token ensureFieldName(XContentParser parser, Token token, String fieldName) throws IOException {
-        Token t = ensureType(Token.FIELD_NAME, token, parser::getTokenLocation);
-
-        String current = parser.currentName() != null ? parser.currentName() : "<null>";
-        if (current.equals(fieldName) == false) {
-            String message = "Failed to parse object: expecting field with name [%s] but found [%s]";
-            throw new ParsingException(parser.getTokenLocation(), String.format(Locale.ROOT, message, fieldName, current));
-        }
-        return t;
-    }
-
     /**
      * @throws ParsingException with a "unknown field found" reason
      */
@@ -72,16 +43,14 @@ public final class XContentParserUtils {
     }
 
     /**
-     * Makes sure that current token is of the expected type
+     * Makes sure that provided token is of the expected type
      *
-     * @return the token
      * @throws ParsingException if the token is not equal to the expected type
      */
-    private static Token ensureType(Token expected, Token current, Supplier<XContentLocation> location) {
-        if (current != expected) {
+    public static void ensureExpectedToken(Token expected, Token actual, Supplier<XContentLocation> location) {
+        if (actual != expected) {
             String message = "Failed to parse object: expecting token of type [%s] but found [%s]";
-            throw new ParsingException(location.get(), String.format(Locale.ROOT, message, expected, current));
+            throw new ParsingException(location.get(), String.format(Locale.ROOT, message, expected, actual));
         }
-        return current;
     }
 }

core/src/main/java/org/elasticsearch/common/xcontent/cbor/CborXContent.java

@@ -26,6 +26,7 @@ import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -78,33 +79,33 @@ public class CborXContent implements XContent {
     }
 
     @Override
-    public XContentParser createParser(String content) throws IOException {
-        return new CborXContentParser(cborFactory.createParser(new FastStringReader(content)));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, String content) throws IOException {
+        return new CborXContentParser(xContentRegistry, cborFactory.createParser(new FastStringReader(content)));
     }
 
     @Override
-    public XContentParser createParser(InputStream is) throws IOException {
-        return new CborXContentParser(cborFactory.createParser(is));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, InputStream is) throws IOException {
+        return new CborXContentParser(xContentRegistry, cborFactory.createParser(is));
     }
 
     @Override
-    public XContentParser createParser(byte[] data) throws IOException {
-        return new CborXContentParser(cborFactory.createParser(data));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data) throws IOException {
+        return new CborXContentParser(xContentRegistry, cborFactory.createParser(data));
     }
 
     @Override
-    public XContentParser createParser(byte[] data, int offset, int length) throws IOException {
-        return new CborXContentParser(cborFactory.createParser(data, offset, length));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data, int offset, int length) throws IOException {
+        return new CborXContentParser(xContentRegistry, cborFactory.createParser(data, offset, length));
     }
 
     @Override
-    public XContentParser createParser(BytesReference bytes) throws IOException {
-        return createParser(bytes.streamInput());
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException {
+        return createParser(xContentRegistry, bytes.streamInput());
     }
 
     @Override
-    public XContentParser createParser(Reader reader) throws IOException {
-        return new CborXContentParser(cborFactory.createParser(reader));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, Reader reader) throws IOException {
+        return new CborXContentParser(xContentRegistry, cborFactory.createParser(reader));
     }
 
 }

core/src/main/java/org/elasticsearch/common/xcontent/cbor/CborXContentParser.java

@@ -20,13 +20,15 @@
 package org.elasticsearch.common.xcontent.cbor;
 
 import com.fasterxml.jackson.core.JsonParser;
+
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.common.xcontent.json.JsonXContentParser;
 
 public class CborXContentParser extends JsonXContentParser {
 
-    public CborXContentParser(JsonParser parser) {
-        super(parser);
+    public CborXContentParser(NamedXContentRegistry xContentRegistry, JsonParser parser) {
+        super(xContentRegistry, parser);
     }
 
     @Override

core/src/main/java/org/elasticsearch/common/xcontent/json/JsonXContent.java

@@ -25,6 +25,7 @@ import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonParser;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -79,32 +80,32 @@ public class JsonXContent implements XContent {
     }
 
     @Override
-    public XContentParser createParser(String content) throws IOException {
-        return new JsonXContentParser(jsonFactory.createParser(new FastStringReader(content)));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, String content) throws IOException {
+        return new JsonXContentParser(xContentRegistry, jsonFactory.createParser(new FastStringReader(content)));
     }
 
     @Override
-    public XContentParser createParser(InputStream is) throws IOException {
-        return new JsonXContentParser(jsonFactory.createParser(is));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, InputStream is) throws IOException {
+        return new JsonXContentParser(xContentRegistry, jsonFactory.createParser(is));
     }
 
     @Override
-    public XContentParser createParser(byte[] data) throws IOException {
-        return new JsonXContentParser(jsonFactory.createParser(data));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data) throws IOException {
+        return new JsonXContentParser(xContentRegistry, jsonFactory.createParser(data));
     }
 
     @Override
-    public XContentParser createParser(byte[] data, int offset, int length) throws IOException {
-        return new JsonXContentParser(jsonFactory.createParser(data, offset, length));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data, int offset, int length) throws IOException {
+        return new JsonXContentParser(xContentRegistry, jsonFactory.createParser(data, offset, length));
     }
 
     @Override
-    public XContentParser createParser(BytesReference bytes) throws IOException {
-        return createParser(bytes.streamInput());
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException {
+        return createParser(xContentRegistry, bytes.streamInput());
     }
 
     @Override
-    public XContentParser createParser(Reader reader) throws IOException {
-        return new JsonXContentParser(jsonFactory.createParser(reader));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, Reader reader) throws IOException {
+        return new JsonXContentParser(xContentRegistry, jsonFactory.createParser(reader));
     }
 }

core/src/main/java/org/elasticsearch/common/xcontent/json/JsonXContentGenerator.java

@@ -31,6 +31,7 @@ import com.fasterxml.jackson.core.util.JsonGeneratorDelegate;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.Streams;
 import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -312,7 +313,8 @@ public class JsonXContentGenerator implements XContentGenerator {
             throw new IllegalArgumentException("Can't write raw bytes whose xcontent-type can't be guessed");
         }
         if (mayWriteRawData(contentType) == false) {
-            try (XContentParser parser = XContentFactory.xContent(contentType).createParser(content)) {
+            // EMPTY is safe here because we never call namedObject when writing raw data
+            try (XContentParser parser = XContentFactory.xContent(contentType).createParser(NamedXContentRegistry.EMPTY, content)) {
                 parser.nextToken();
                 writeFieldName(name);
                 copyCurrentStructure(parser);
@@ -378,8 +380,9 @@ public class JsonXContentGenerator implements XContentGenerator {
     }
 
     protected void copyRawValue(BytesReference content, XContent xContent) throws IOException {
+        // EMPTY is safe here because we never call namedObject
         try (StreamInput input = content.streamInput();
-             XContentParser parser = xContent.createParser(input)) {
+             XContentParser parser = xContent.createParser(NamedXContentRegistry.EMPTY, input)) {
             copyCurrentStructure(parser);
         }
     }

core/src/main/java/org/elasticsearch/common/xcontent/json/JsonXContentParser.java

@@ -22,8 +22,10 @@ package org.elasticsearch.common.xcontent.json;
 import com.fasterxml.jackson.core.JsonLocation;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
+
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentLocation;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.common.xcontent.support.AbstractXContentParser;
@@ -35,7 +37,8 @@ public class JsonXContentParser extends AbstractXContentParser {
 
     final JsonParser parser;
 
-    public JsonXContentParser(JsonParser parser) {
+    public JsonXContentParser(NamedXContentRegistry xContentRegistry, JsonParser parser) {
+        super(xContentRegistry);
         this.parser = parser;
     }
 

core/src/main/java/org/elasticsearch/common/xcontent/smile/SmileXContent.java

@@ -26,6 +26,7 @@ import com.fasterxml.jackson.dataformat.smile.SmileFactory;
 import com.fasterxml.jackson.dataformat.smile.SmileGenerator;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -79,32 +80,32 @@ public class SmileXContent implements XContent {
     }
 
     @Override
-    public XContentParser createParser(String content) throws IOException {
-        return new SmileXContentParser(smileFactory.createParser(new FastStringReader(content)));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, String content) throws IOException {
+        return new SmileXContentParser(xContentRegistry, smileFactory.createParser(new FastStringReader(content)));
     }
 
     @Override
-    public XContentParser createParser(InputStream is) throws IOException {
-        return new SmileXContentParser(smileFactory.createParser(is));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, InputStream is) throws IOException {
+        return new SmileXContentParser(xContentRegistry, smileFactory.createParser(is));
     }
 
     @Override
-    public XContentParser createParser(byte[] data) throws IOException {
-        return new SmileXContentParser(smileFactory.createParser(data));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data) throws IOException {
+        return new SmileXContentParser(xContentRegistry, smileFactory.createParser(data));
     }
 
     @Override
-    public XContentParser createParser(byte[] data, int offset, int length) throws IOException {
-        return new SmileXContentParser(smileFactory.createParser(data, offset, length));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data, int offset, int length) throws IOException {
+        return new SmileXContentParser(xContentRegistry, smileFactory.createParser(data, offset, length));
     }
 
     @Override
-    public XContentParser createParser(BytesReference bytes) throws IOException {
-        return createParser(bytes.streamInput());
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException {
+        return createParser(xContentRegistry, bytes.streamInput());
     }
 
     @Override
-    public XContentParser createParser(Reader reader) throws IOException {
-        return new SmileXContentParser(smileFactory.createParser(reader));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, Reader reader) throws IOException {
+        return new SmileXContentParser(xContentRegistry, smileFactory.createParser(reader));
     }
 }

core/src/main/java/org/elasticsearch/common/xcontent/smile/SmileXContentParser.java

@@ -20,13 +20,15 @@
 package org.elasticsearch.common.xcontent.smile;
 
 import com.fasterxml.jackson.core.JsonParser;
+
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.common.xcontent.json.JsonXContentParser;
 
 public class SmileXContentParser extends JsonXContentParser {
 
-    public SmileXContentParser(JsonParser parser) {
-        super(parser);
+    public SmileXContentParser(NamedXContentRegistry xContentRegistry, JsonParser parser) {
+        super(xContentRegistry, parser);
     }
 
     @Override

core/src/main/java/org/elasticsearch/common/xcontent/support/AbstractXContentParser.java

@@ -22,6 +22,7 @@ package org.elasticsearch.common.xcontent.support;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.Booleans;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentParser;
 
 import java.io.IOException;
@@ -49,7 +50,11 @@ public abstract class AbstractXContentParser implements XContentParser {
         }
     }
 
+    private final NamedXContentRegistry xContentRegistry;
 
+    public AbstractXContentParser(NamedXContentRegistry xContentRegistry) {
+        this.xContentRegistry = xContentRegistry;
+    }
 
     // The 3rd party parsers we rely on are known to silently truncate fractions: see
     //   http://fasterxml.github.io/jackson-core/javadoc/2.3.0/com/fasterxml/jackson/core/JsonParser.html#getShortValue()
@@ -356,6 +361,16 @@ public abstract class AbstractXContentParser implements XContentParser {
         return null;
     }
 
+    @Override
+    public <T> T namedObject(Class<T> categoryClass, String name, Object context) throws IOException {
+        return xContentRegistry.parseNamedObject(categoryClass, name, this, context);
+    }
+
+    @Override
+    public NamedXContentRegistry getXContentRegistry() {
+        return xContentRegistry;
+    }
+
     @Override
     public abstract boolean isClosed();
 }

core/src/main/java/org/elasticsearch/common/xcontent/yaml/YamlXContent.java

@@ -25,6 +25,7 @@ import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentGenerator;
@@ -74,32 +75,32 @@ public class YamlXContent implements XContent {
     }
 
     @Override
-    public XContentParser createParser(String content) throws IOException {
-        return new YamlXContentParser(yamlFactory.createParser(new FastStringReader(content)));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, String content) throws IOException {
+        return new YamlXContentParser(xContentRegistry, yamlFactory.createParser(new FastStringReader(content)));
     }
 
     @Override
-    public XContentParser createParser(InputStream is) throws IOException {
-        return new YamlXContentParser(yamlFactory.createParser(is));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, InputStream is) throws IOException {
+        return new YamlXContentParser(xContentRegistry, yamlFactory.createParser(is));
     }
 
     @Override
-    public XContentParser createParser(byte[] data) throws IOException {
-        return new YamlXContentParser(yamlFactory.createParser(data));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data) throws IOException {
+        return new YamlXContentParser(xContentRegistry, yamlFactory.createParser(data));
     }
 
     @Override
-    public XContentParser createParser(byte[] data, int offset, int length) throws IOException {
-        return new YamlXContentParser(yamlFactory.createParser(data, offset, length));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, byte[] data, int offset, int length) throws IOException {
+        return new YamlXContentParser(xContentRegistry, yamlFactory.createParser(data, offset, length));
     }
 
     @Override
-    public XContentParser createParser(BytesReference bytes) throws IOException {
-        return createParser(bytes.streamInput());
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, BytesReference bytes) throws IOException {
+        return createParser(xContentRegistry, bytes.streamInput());
     }
 
     @Override
-    public XContentParser createParser(Reader reader) throws IOException {
-        return new YamlXContentParser(yamlFactory.createParser(reader));
+    public XContentParser createParser(NamedXContentRegistry xContentRegistry, Reader reader) throws IOException {
+        return new YamlXContentParser(xContentRegistry, yamlFactory.createParser(reader));
     }
 }

core/src/main/java/org/elasticsearch/common/xcontent/yaml/YamlXContentParser.java

@@ -20,13 +20,15 @@
 package org.elasticsearch.common.xcontent.yaml;
 
 import com.fasterxml.jackson.core.JsonParser;
+
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.common.xcontent.json.JsonXContentParser;
 
 public class YamlXContentParser extends JsonXContentParser {
 
-    public YamlXContentParser(JsonParser parser) {
-        super(parser);
+    public YamlXContentParser(NamedXContentRegistry xContentRegistry, JsonParser parser) {
+        super(xContentRegistry, parser);
     }
 
     @Override

core/src/main/java/org/elasticsearch/gateway/MetaDataStateFormat.java

@@ -35,6 +35,7 @@ import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.lucene.store.IndexOutputOutputStream;
 import org.elasticsearch.common.lucene.store.InputStreamIndexInput;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
@@ -196,8 +197,9 @@ public abstract class MetaDataStateFormat<T> {
                 long filePointer = indexInput.getFilePointer();
                 long contentSize = indexInput.length() - CodecUtil.footerLength() - filePointer;
                 try (IndexInput slice = indexInput.slice("state_xcontent", filePointer, contentSize)) {
-                    try (XContentParser parser = XContentFactory.xContent(xContentType).createParser(new InputStreamIndexInput(slice,
-                        contentSize))) {
+                    // It is safe to use EMPTY here because this never uses namedObject
+                    try (XContentParser parser = XContentFactory.xContent(xContentType).createParser(NamedXContentRegistry.EMPTY,
+                            new InputStreamIndexInput(slice, contentSize))) {
                         return fromXContent(parser);
                     }
                 }
@@ -311,7 +313,8 @@ public abstract class MetaDataStateFormat<T> {
                         logger.debug("{}: no data for [{}], ignoring...", prefix, stateFile.toAbsolutePath());
                         continue;
                     }
-                    try (final XContentParser parser = XContentHelper.createParser(new BytesArray(data))) {
+                    // EMPTY is safe here because no parser uses namedObject
+                    try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, new BytesArray(data))) {
                         state = fromXContent(parser);
                     }
                     if (state == null) {

core/src/main/java/org/elasticsearch/index/IndexModule.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.BigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.index.analysis.AnalysisRegistry;
 import org.elasticsearch.index.cache.query.DisabledQueryCache;
@@ -320,6 +321,7 @@ public final class IndexModule {
 
     public IndexService newIndexService(
         NodeEnvironment environment,
+        NamedXContentRegistry xContentRegistry,
         IndexService.ShardStoreDeleter shardStoreDeleter,
         CircuitBreakerService circuitBreakerService,
         BigArrays bigArrays,
@@ -362,18 +364,18 @@ public final class IndexModule {
         } else {
             queryCache = new DisabledQueryCache(indexSettings);
         }
-        return new IndexService(indexSettings, environment, new SimilarityService(indexSettings, similarities), shardStoreDeleter,
-                analysisRegistry, engineFactory.get(), circuitBreakerService, bigArrays, threadPool, scriptService, indicesQueriesRegistry,
-                clusterService, client, queryCache, store, eventListener, searcherWrapperFactory, mapperRegistry, indicesFieldDataCache,
-                globalCheckpointSyncer, searchOperationListeners, indexOperationListeners);
+        return new IndexService(indexSettings, environment, xContentRegistry, new SimilarityService(indexSettings, similarities),
+                shardStoreDeleter, analysisRegistry, engineFactory.get(), circuitBreakerService, bigArrays, threadPool, scriptService,
+                indicesQueriesRegistry, clusterService, client, queryCache, store, eventListener, searcherWrapperFactory, mapperRegistry,
+                indicesFieldDataCache, globalCheckpointSyncer, searchOperationListeners, indexOperationListeners);
     }
 
     /**
      * creates a new mapper service to do administrative work like mapping updates. This *should not* be used for document parsing.
      * doing so will result in an exception.
      */
-    public MapperService newIndexMapperService(MapperRegistry mapperRegistry) throws IOException {
-        return new MapperService(indexSettings, analysisRegistry.build(indexSettings),
+    public MapperService newIndexMapperService(NamedXContentRegistry xContentRegistry, MapperRegistry mapperRegistry) throws IOException {
+        return new MapperService(indexSettings, analysisRegistry.build(indexSettings), xContentRegistry,
             new SimilarityService(indexSettings, similarities), mapperRegistry,
             () -> { throw new UnsupportedOperationException("no index query shard context available"); });
     }

core/src/main/java/org/elasticsearch/index/IndexService.java

@@ -34,6 +34,7 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.concurrent.FutureUtils;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.env.ShardLock;
 import org.elasticsearch.env.ShardLockObtainFailedException;
@@ -102,6 +103,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     private final IndexSearcherWrapper searcherWrapper;
     private final IndexCache indexCache;
     private final MapperService mapperService;
+    private final NamedXContentRegistry xContentRegistry;
     private final SimilarityService similarityService;
     private final EngineFactory engineFactory;
     private final IndexWarmer warmer;
@@ -123,6 +125,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     private final Client client;
 
     public IndexService(IndexSettings indexSettings, NodeEnvironment nodeEnv,
+                        NamedXContentRegistry xContentRegistry,
                         SimilarityService similarityService,
                         ShardStoreDeleter shardStoreDeleter,
                         AnalysisRegistry registry,
@@ -146,8 +149,10 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
         super(indexSettings);
         this.indexSettings = indexSettings;
         this.globalCheckpointSyncer = globalCheckpointSyncer;
+        this.xContentRegistry = xContentRegistry;
         this.similarityService = similarityService;
-        this.mapperService = new MapperService(indexSettings, registry.build(indexSettings), similarityService, mapperRegistry,
+        this.mapperService = new MapperService(indexSettings, registry.build(indexSettings), xContentRegistry, similarityService,
+            mapperRegistry,
             // we parse all percolator queries as they would be parsed on shard 0
             () -> newQueryShardContext(0, null, () -> {
                 throw new IllegalArgumentException("Percolator queries are not allowed to use the current timestamp");
@@ -236,6 +241,10 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
         return mapperService;
     }
 
+    public NamedXContentRegistry xContentRegistry() {
+        return xContentRegistry;
+    }
+
     public SimilarityService similarityService() {
         return similarityService;
     }
@@ -469,7 +478,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     public QueryShardContext newQueryShardContext(int shardId, IndexReader indexReader, LongSupplier nowInMillis) {
         return new QueryShardContext(
             shardId, indexSettings, indexCache.bitsetFilterCache(), indexFieldData, mapperService(),
-                similarityService(), scriptService, queryRegistry,
+                similarityService(), scriptService, xContentRegistry, queryRegistry,
                 client, indexReader,
             nowInMillis);
     }

core/src/main/java/org/elasticsearch/index/get/GetField.java

@@ -19,17 +19,25 @@
 
 package org.elasticsearch.index.get;
 
+import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Streamable;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.mapper.MapperService;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
 
-public class GetField implements Streamable, Iterable<Object> {
+import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
+
+public class GetField implements Streamable, ToXContent, Iterable<Object> {
 
     private String name;
     private List<Object> values;
@@ -38,8 +46,8 @@ public class GetField implements Streamable, Iterable<Object> {
     }
 
     public GetField(String name, List<Object> values) {
-        this.name = name;
-        this.values = values;
+        this.name = Objects.requireNonNull(name, "name must not be null");
+        this.values = Objects.requireNonNull(values, "values must not be null");
     }
 
     public String getName() {
@@ -90,4 +98,69 @@ public class GetField implements Streamable, Iterable<Object> {
             out.writeGenericValue(obj);
         }
     }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startArray(name);
+        for (Object value : values) {
+            //this call doesn't really need to support writing any kind of object.
+            //Stored fields values are converted using MappedFieldType#valueForDisplay.
+            //As a result they can either be Strings, Numbers, Booleans, or BytesReference, that's all.
+            builder.value(value);
+        }
+        builder.endArray();
+        return builder;
+    }
+
+    public static GetField fromXContent(XContentParser parser) throws IOException {
+        ensureExpectedToken(XContentParser.Token.FIELD_NAME, parser.currentToken(), parser::getTokenLocation);
+        String fieldName = parser.currentName();
+        XContentParser.Token token = parser.nextToken();
+        ensureExpectedToken(XContentParser.Token.START_ARRAY, token, parser::getTokenLocation);
+        List<Object> values = new ArrayList<>();
+        while((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
+            Object value;
+            if (token == XContentParser.Token.VALUE_STRING) {
+                //binary values will be parsed back and returned as base64 strings when reading from json and yaml
+                value = parser.text();
+            } else if (token == XContentParser.Token.VALUE_NUMBER) {
+                value = parser.numberValue();
+            } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
+                value = parser.booleanValue();
+            } else if (token == XContentParser.Token.VALUE_EMBEDDED_OBJECT) {
+                //binary values will be parsed back and returned as BytesArray when reading from cbor and smile
+                value = new BytesArray(parser.binaryValue());
+            } else {
+                throw new ParsingException(parser.getTokenLocation(), "Failed to parse object: unsupported token found [" + token + "]");
+            }
+            values.add(value);
+        }
+        return new GetField(fieldName, values);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        GetField objects = (GetField) o;
+        return Objects.equals(name, objects.name) &&
+                Objects.equals(values, objects.values);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, values);
+    }
+
+    @Override
+    public String toString() {
+        return "GetField{" +
+                "name='" + name + '\'' +
+                ", values=" + values +
+                '}';
+    }
 }

core/src/main/java/org/elasticsearch/index/get/GetResult.java

@@ -28,6 +28,7 @@ import org.elasticsearch.common.io.stream.Streamable;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.mapper.SourceFieldMapper;
 import org.elasticsearch.search.lookup.SourceLookup;
 
@@ -38,12 +39,22 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 import static java.util.Collections.emptyMap;
+import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
+import static org.elasticsearch.common.xcontent.XContentParserUtils.throwUnknownField;
 import static org.elasticsearch.index.get.GetField.readGetField;
 
 public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
 
+    private static final String _INDEX = "_index";
+    private static final String _TYPE = "_type";
+    private static final String _ID = "_id";
+    private static final String _VERSION = "_version";
+    private static final String FOUND = "found";
+    private static final String FIELDS = "fields";
+    
     private String index;
     private String type;
     private String id;
@@ -57,7 +68,8 @@ public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
     GetResult() {
     }
 
-    public GetResult(String index, String type, String id, long version, boolean exists, BytesReference source, Map<String, GetField> fields) {
+    public GetResult(String index, String type, String id, long version, boolean exists, BytesReference source,
+                     Map<String, GetField> fields) {
         this.index = index;
         this.type = type;
         this.id = id;
@@ -196,15 +208,6 @@ public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
         return fields.values().iterator();
     }
 
-    static final class Fields {
-        static final String _INDEX = "_index";
-        static final String _TYPE = "_type";
-        static final String _ID = "_id";
-        static final String _VERSION = "_version";
-        static final String FOUND = "found";
-        static final String FIELDS = "fields";
-    }
-
     public XContentBuilder toXContentEmbedded(XContentBuilder builder, Params params) throws IOException {
         List<GetField> metaFields = new ArrayList<>();
         List<GetField> otherFields = new ArrayList<>();
@@ -225,20 +228,16 @@ public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
             builder.field(field.getName(), field.getValue());
         }
 
-        builder.field(Fields.FOUND, exists);
+        builder.field(FOUND, exists);
 
         if (source != null) {
             XContentHelper.writeRawField(SourceFieldMapper.NAME, source, builder, params);
         }
 
         if (!otherFields.isEmpty()) {
-            builder.startObject(Fields.FIELDS);
+            builder.startObject(FIELDS);
             for (GetField field : otherFields) {
-                builder.startArray(field.getName());
-                for (Object value : field.getValues()) {
-                    builder.value(value);
-                }
-                builder.endArray();
+                field.toXContent(builder, params);
             }
             builder.endObject();
         }
@@ -247,23 +246,69 @@ public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-        if (!isExists()) {
-            builder.field(Fields._INDEX, index);
-            builder.field(Fields._TYPE, type);
-            builder.field(Fields._ID, id);
-            builder.field(Fields.FOUND, false);
-        } else {
-            builder.field(Fields._INDEX, index);
-            builder.field(Fields._TYPE, type);
-            builder.field(Fields._ID, id);
+        builder.startObject();
+        builder.field(_INDEX, index);
+        builder.field(_TYPE, type);
+        builder.field(_ID, id);
+        if (isExists()) {
             if (version != -1) {
-                builder.field(Fields._VERSION, version);
+                builder.field(_VERSION, version);
             }
             toXContentEmbedded(builder, params);
+        } else {
+            builder.field(FOUND, false);
         }
+        builder.endObject();
         return builder;
     }
 
+    public static GetResult fromXContent(XContentParser parser) throws IOException {
+        XContentParser.Token token = parser.nextToken();
+        ensureExpectedToken(XContentParser.Token.START_OBJECT, token, parser::getTokenLocation);
+        String currentFieldName = null;
+        String index = null, type = null, id = null;
+        long version = -1;
+        boolean found = false;
+        BytesReference source = null;
+        Map<String, GetField> fields = new HashMap<>();
+        while((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+            } else if (token.isValue()) {
+                if (_INDEX.equals(currentFieldName)) {
+                    index = parser.text();
+                } else if (_TYPE.equals(currentFieldName)) {
+                    type = parser.text();
+                } else if (_ID.equals(currentFieldName)) {
+                    id = parser.text();
+                }  else if (_VERSION.equals(currentFieldName)) {
+                    version = parser.longValue();
+                } else if (FOUND.equals(currentFieldName)) {
+                    found = parser.booleanValue();
+                } else {
+                    fields.put(currentFieldName, new GetField(currentFieldName, Collections.singletonList(parser.objectText())));
+                }
+            } else if (token == XContentParser.Token.START_OBJECT) {
+                if (SourceFieldMapper.NAME.equals(currentFieldName)) {
+                    try (XContentBuilder builder = XContentBuilder.builder(parser.contentType().xContent())) {
+                        //the original document gets slightly modified: whitespaces or pretty printing are not preserved,
+                        //it all depends on the current builder settings
+                        builder.copyCurrentStructure(parser);
+                        source = builder.bytes();
+                    }
+                } else if (FIELDS.equals(currentFieldName)) {
+                    while(parser.nextToken() != XContentParser.Token.END_OBJECT) {
+                        GetField getField = GetField.fromXContent(parser);
+                        fields.put(getField.getName(), getField);
+                    }
+                } else {
+                    throwUnknownField(currentFieldName, parser.getTokenLocation());
+                }
+            }
+        }
+        return new GetResult(index, type, id, version, found, source, fields);
+    }
+
     public static GetResult readGetResult(StreamInput in) throws IOException {
         GetResult result = new GetResult();
         result.readFrom(in);
@@ -314,5 +359,28 @@ public class GetResult implements Streamable, Iterable<GetField>, ToXContent {
             }
         }
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        GetResult getResult = (GetResult) o;
+        return version == getResult.version &&
+                exists == getResult.exists &&
+                Objects.equals(index, getResult.index) &&
+                Objects.equals(type, getResult.type) &&
+                Objects.equals(id, getResult.id) &&
+                Objects.equals(fields, getResult.fields) &&
+                Objects.equals(sourceAsMap(), getResult.sourceAsMap());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(index, type, id, version, exists, fields, sourceAsMap());
+    }
 }
 

core/src/main/java/org/elasticsearch/index/mapper/DocumentMapperParser.java

@@ -24,6 +24,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.compress.CompressedXContent;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -44,6 +45,7 @@ public class DocumentMapperParser {
 
     final MapperService mapperService;
     final IndexAnalyzers indexAnalyzers;
+    private final NamedXContentRegistry xContentRegistry;
     private final SimilarityService similarityService;
     private final Supplier<QueryShardContext> queryShardContextSupplier;
 
@@ -56,11 +58,12 @@ public class DocumentMapperParser {
     private final Map<String, MetadataFieldMapper.TypeParser> rootTypeParsers;
 
     public DocumentMapperParser(IndexSettings indexSettings, MapperService mapperService, IndexAnalyzers indexAnalyzers,
-                                SimilarityService similarityService, MapperRegistry mapperRegistry,
+                                NamedXContentRegistry xContentRegistry, SimilarityService similarityService, MapperRegistry mapperRegistry,
                                 Supplier<QueryShardContext> queryShardContextSupplier) {
         this.parseFieldMatcher = new ParseFieldMatcher(indexSettings.getSettings());
         this.mapperService = mapperService;
         this.indexAnalyzers = indexAnalyzers;
+        this.xContentRegistry = xContentRegistry;
         this.similarityService = similarityService;
         this.queryShardContextSupplier = queryShardContextSupplier;
         this.typeParsers = mapperRegistry.getMapperParsers();
@@ -159,7 +162,7 @@ public class DocumentMapperParser {
 
     private Tuple<String, Map<String, Object>> extractMapping(String type, String source) throws MapperParsingException {
         Map<String, Object> root;
-        try (XContentParser parser = XContentFactory.xContent(source).createParser(source)) {
+        try (XContentParser parser = XContentFactory.xContent(source).createParser(xContentRegistry, source)) {
             root = parser.mapOrdered();
         } catch (Exception e) {
             throw new MapperParsingException("failed to parse mapping definition", e);
@@ -182,4 +185,8 @@ public class DocumentMapperParser {
         }
         return mapping;
     }
+
+    NamedXContentRegistry getXContentRegistry() {
+        return xContentRegistry;
+    }
 }

core/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java

@@ -58,7 +58,7 @@ final class DocumentParser {
 
         final Mapping mapping = docMapper.mapping();
         final ParseContext.InternalParseContext context;
-        try (XContentParser parser = XContentHelper.createParser(source.source())) {
+        try (XContentParser parser = XContentHelper.createParser(docMapperParser.getXContentRegistry(), source.source())) {
             context = new ParseContext.InternalParseContext(indexSettings.getSettings(),
                     docMapperParser, docMapper, source, parser);
             validateStart(parser);

core/src/main/java/org/elasticsearch/index/mapper/MapperService.java

@@ -33,6 +33,7 @@ import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.AbstractIndexComponent;
@@ -127,13 +128,14 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
 
     final MapperRegistry mapperRegistry;
 
-    public MapperService(IndexSettings indexSettings, IndexAnalyzers indexAnalyzers,
+    public MapperService(IndexSettings indexSettings, IndexAnalyzers indexAnalyzers, NamedXContentRegistry xContentRegistry,
                          SimilarityService similarityService, MapperRegistry mapperRegistry,
                          Supplier<QueryShardContext> queryShardContextSupplier) {
         super(indexSettings);
         this.indexAnalyzers = indexAnalyzers;
         this.fieldTypes = new FieldTypeLookup();
-        this.documentParser = new DocumentMapperParser(indexSettings, this, indexAnalyzers, similarityService, mapperRegistry, queryShardContextSupplier);
+        this.documentParser = new DocumentMapperParser(indexSettings, this, indexAnalyzers, xContentRegistry, similarityService,
+                mapperRegistry, queryShardContextSupplier);
         this.indexAnalyzer = new MapperAnalyzerWrapper(indexAnalyzers.getDefaultIndexAnalyzer(), p -> p.indexAnalyzer());
         this.searchAnalyzer = new MapperAnalyzerWrapper(indexAnalyzers.getDefaultSearchAnalyzer(), p -> p.searchAnalyzer());
         this.searchQuoteAnalyzer = new MapperAnalyzerWrapper(indexAnalyzers.getDefaultSearchQuoteAnalyzer(), p -> p.searchQuoteAnalyzer());
@@ -186,8 +188,8 @@ public class MapperService extends AbstractIndexComponent implements Closeable {
         return this.documentParser;
     }
 
-    public static Map<String, Object> parseMapping(String mappingSource) throws Exception {
-        try (XContentParser parser = XContentFactory.xContent(mappingSource).createParser(mappingSource)) {
+    public static Map<String, Object> parseMapping(NamedXContentRegistry xContentRegistry, String mappingSource) throws Exception {
+        try (XContentParser parser = XContentFactory.xContent(mappingSource).createParser(xContentRegistry, mappingSource)) {
             return parser.map();
         }
     }

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

@@ -25,7 +25,6 @@ import org.elasticsearch.Version;
 import org.elasticsearch.common.joda.FormatDateTimeFormatter;
 import org.elasticsearch.common.joda.Joda;
 import org.elasticsearch.common.logging.DeprecationLogger;
-import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
@@ -43,7 +42,6 @@ import java.util.Set;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.isArray;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.lenientNodeBooleanValue;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeFloatValue;
-import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeIntegerValue;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeMapValue;
 import static org.elasticsearch.common.xcontent.support.XContentMapValues.nodeStringValue;
 
@@ -59,16 +57,11 @@ public class TypeParsers {
     private static final Set<String> BOOLEAN_STRINGS = new HashSet<>(Arrays.asList("true", "false"));
 
     public static boolean nodeBooleanValue(String name, Object node, Mapper.TypeParser.ParserContext parserContext) {
-        // Hook onto ParseFieldMatcher so that parsing becomes strict when setting index.query.parse.strict
-        if (parserContext.parseFieldMatcher().isStrict()) {
-            return XContentMapValues.nodeBooleanValue(node);
-        } else {
-            // TODO: remove this leniency in 6.0
-            if (BOOLEAN_STRINGS.contains(node.toString()) == false) {
-                DEPRECATION_LOGGER.deprecated("Expected a boolean for property [{}] but got [{}]", name, node);
-            }
-            return XContentMapValues.lenientNodeBooleanValue(node);
+        // TODO: remove this leniency in 6.0
+        if (BOOLEAN_STRINGS.contains(node.toString()) == false) {
+            DEPRECATION_LOGGER.deprecated("Expected a boolean for property [{}] but got [{}]", name, node);
         }
+        return XContentMapValues.lenientNodeBooleanValue(node);
     }
 
     private static void parseAnalyzersAndTermVectors(FieldMapper.Builder builder, String name, Map<String, Object> fieldNode, Mapper.TypeParser.ParserContext parserContext) {
@@ -211,10 +204,10 @@ public class TypeParsers {
                 throw new MapperParsingException("[" + propName + "] must not have a [null] value");
             }
             if (propName.equals("store")) {
-                builder.store(parseStore(name, propNode.toString(), parserContext));
+                builder.store(parseStore(propNode.toString()));
                 iterator.remove();
             } else if (propName.equals("index")) {
-                builder.index(parseIndex(name, propNode.toString(), parserContext));
+                builder.index(parseIndex(name, propNode.toString()));
                 iterator.remove();
             } else if (propName.equals(DOC_VALUES)) {
                 builder.docValues(nodeBooleanValue(DOC_VALUES, propNode, parserContext));
@@ -229,7 +222,11 @@ public class TypeParsers {
                 builder.indexOptions(nodeIndexOptionValue(propNode));
                 iterator.remove();
             } else if (propName.equals("include_in_all")) {
-                builder.includeInAll(nodeBooleanValue("include_in_all", propNode, parserContext));
+                if (parserContext.isWithinMultiField()) {
+                    throw new MapperParsingException("include_in_all in multi fields is not allowed. Found the include_in_all in field [" + name + "] which is within a multi field.");
+                } else {
+                    builder.includeInAll(nodeBooleanValue("include_in_all", propNode, parserContext));
+                }
                 iterator.remove();
             } else if (propName.equals("similarity")) {
                 SimilarityProvider similarityProvider = resolveSimilarity(parserContext, name, propNode.toString());
@@ -346,7 +343,7 @@ public class TypeParsers {
         }
     }
 
-    public static boolean parseIndex(String fieldName, String index, Mapper.TypeParser.ParserContext parserContext) throws MapperParsingException {
+    private static boolean parseIndex(String fieldName, String index) throws MapperParsingException {
         switch (index) {
         case "true":
             return true;
@@ -355,31 +352,23 @@ public class TypeParsers {
         case "not_analyzed":
         case "analyzed":
         case "no":
-            if (parserContext.parseFieldMatcher().isStrict() == false) {
-                DEPRECATION_LOGGER.deprecated("Expected a boolean for property [index] but got [{}]", index);
-                return "no".equals(index) == false;
-            } else {
-                throw new IllegalArgumentException("Can't parse [index] value [" + index + "] for field [" + fieldName + "], expected [true] or [false]");
-            }
+            DEPRECATION_LOGGER.deprecated("Expected a boolean for property [index] but got [{}]", index);
+            return "no".equals(index) == false;
         default:
             throw new IllegalArgumentException("Can't parse [index] value [" + index + "] for field [" + fieldName + "], expected [true] or [false]");
         }
     }
 
-    public static boolean parseStore(String fieldName, String store, Mapper.TypeParser.ParserContext parserContext) throws MapperParsingException {
-        if (parserContext.parseFieldMatcher().isStrict()) {
-            return XContentMapValues.nodeBooleanValue(store);
+    private static boolean parseStore(String store) throws MapperParsingException {
+        if (BOOLEAN_STRINGS.contains(store) == false) {
+            DEPRECATION_LOGGER.deprecated("Expected a boolean for property [store] but got [{}]", store);
+        }
+        if ("no".equals(store)) {
+            return false;
+        } else if ("yes".equals(store)) {
+            return true;
         } else {
-            if (BOOLEAN_STRINGS.contains(store) == false) {
-                DEPRECATION_LOGGER.deprecated("Expected a boolean for property [store] but got [{}]", store);
-            }
-            if ("no".equals(store)) {
-                return false;
-            } else if ("yes".equals(store)) {
-                return true;
-            } else {
-                return lenientNodeBooleanValue(store);
-            }
+            return lenientNodeBooleanValue(store);
         }
     }
 

core/src/main/java/org/elasticsearch/index/query/GeoBoundingBoxQueryBuilder.java

@@ -62,9 +62,9 @@ public class GeoBoundingBoxQueryBuilder extends AbstractQueryBuilder<GeoBounding
     private static final ParseField TYPE_FIELD = new ParseField("type");
     private static final ParseField VALIDATION_METHOD_FIELD = new ParseField("validation_method");
     private static final ParseField COERCE_FIELD =new ParseField("coerce", "normalize")
-            .withAllDeprecated("use field validation_method instead");
+            .withAllDeprecated("validation_method");
     private static final ParseField IGNORE_MALFORMED_FIELD = new ParseField("ignore_malformed")
-            .withAllDeprecated("use field validation_method instead");
+            .withAllDeprecated("validation_method");
     private static final ParseField FIELD_FIELD = new ParseField("field");
     private static final ParseField TOP_FIELD = new ParseField("top");
     private static final ParseField BOTTOM_FIELD = new ParseField("bottom");

core/src/main/java/org/elasticsearch/index/query/GeoDistanceQueryBuilder.java

@@ -66,10 +66,8 @@ public class GeoDistanceQueryBuilder extends AbstractQueryBuilder<GeoDistanceQue
     public static final boolean DEFAULT_IGNORE_UNMAPPED = false;
 
     private static final ParseField VALIDATION_METHOD_FIELD = new ParseField("validation_method");
-    private static final ParseField IGNORE_MALFORMED_FIELD = new ParseField("ignore_malformed")
-            .withAllDeprecated("use validation_method instead");
-    private static final ParseField COERCE_FIELD = new ParseField("coerce", "normalize")
-            .withAllDeprecated("use validation_method instead");
+    private static final ParseField IGNORE_MALFORMED_FIELD = new ParseField("ignore_malformed").withAllDeprecated("validation_method");
+    private static final ParseField COERCE_FIELD = new ParseField("coerce", "normalize").withAllDeprecated("validation_method");
     @Deprecated
     private static final ParseField OPTIMIZE_BBOX_FIELD = new ParseField("optimize_bbox")
             .withAllDeprecated("no replacement: `optimize_bbox` is no longer supported due to recent improvements");

core/src/main/java/org/elasticsearch/index/query/GeoPolygonQueryBuilder.java

@@ -49,10 +49,8 @@ public class GeoPolygonQueryBuilder extends AbstractQueryBuilder<GeoPolygonQuery
      */
     public static final boolean DEFAULT_IGNORE_UNMAPPED = false;
 
-    private static final ParseField COERCE_FIELD = new ParseField("coerce", "normalize")
-            .withAllDeprecated("use validation_method instead");
-    private static final ParseField IGNORE_MALFORMED_FIELD = new ParseField("ignore_malformed")
-            .withAllDeprecated("use validation_method instead");
+    private static final ParseField COERCE_FIELD = new ParseField("coerce", "normalize").withAllDeprecated("validation_method");
+    private static final ParseField IGNORE_MALFORMED_FIELD = new ParseField("ignore_malformed").withAllDeprecated("validation_method");
     private static final ParseField VALIDATION_METHOD = new ParseField("validation_method");
     private static final ParseField POINTS_FIELD = new ParseField("points");
     private static final ParseField IGNORE_UNMAPPED_FIELD = new ParseField("ignore_unmapped");

core/src/main/java/org/elasticsearch/index/query/GeoShapeQueryBuilder.java

@@ -39,6 +39,7 @@ import org.elasticsearch.common.geo.SpatialStrategy;
 import org.elasticsearch.common.geo.builders.ShapeBuilder;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -383,7 +384,8 @@ public class GeoShapeQueryBuilder extends AbstractQueryBuilder<GeoShapeQueryBuil
         String[] pathElements = path.split("\\.");
         int currentPathSlot = 0;
 
-        try (XContentParser parser = XContentHelper.createParser(response.getSourceAsBytesRef())) {
+        // It is safe to use EMPTY here because this never uses namedObject
+        try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, response.getSourceAsBytesRef())) {
             XContentParser.Token currentToken;
             while ((currentToken = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                 if (currentToken == XContentParser.Token.FIELD_NAME) {

core/src/main/java/org/elasticsearch/index/query/MoreLikeThisQueryBuilder.java

@@ -52,10 +52,10 @@ import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.index.VersionType;
-import org.elasticsearch.index.mapper.MappedFieldType;
-import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.mapper.KeywordFieldMapper.KeywordFieldType;
+import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.TextFieldMapper.TextFieldType;
+import org.elasticsearch.index.mapper.UidFieldMapper;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -421,11 +421,7 @@ public class MoreLikeThisQueryBuilder extends AbstractQueryBuilder<MoreLikeThisQ
                 if (contentType == builder.contentType()) {
                     builder.rawField(Field.DOC.getPreferredName(), this.doc);
                 } else {
-                    try (XContentParser parser = XContentFactory.xContent(contentType).createParser(this.doc)) {
-                        parser.nextToken();
-                        builder.field(Field.DOC.getPreferredName());
-                        builder.copyCurrentStructure(parser);
-                    }
+                    builder.rawField(Field.DOC.getPreferredName(), doc);
                 }
             }
             if (this.fields != null) {

core/src/main/java/org/elasticsearch/index/query/QueryRewriteContext.java

@@ -23,6 +23,7 @@ import org.elasticsearch.client.Client;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParseFieldMatcherSupplier;
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.MapperService;
@@ -41,17 +42,19 @@ public class QueryRewriteContext implements ParseFieldMatcherSupplier {
     protected final MapperService mapperService;
     protected final ScriptService scriptService;
     protected final IndexSettings indexSettings;
+    private final NamedXContentRegistry xContentRegistry;
     protected final IndicesQueriesRegistry indicesQueriesRegistry;
     protected final Client client;
     protected final IndexReader reader;
     protected final LongSupplier nowInMillis;
 
     public QueryRewriteContext(IndexSettings indexSettings, MapperService mapperService, ScriptService scriptService,
-                               IndicesQueriesRegistry indicesQueriesRegistry, Client client, IndexReader reader,
-                               LongSupplier nowInMillis) {
+            NamedXContentRegistry xContentRegistry, IndicesQueriesRegistry indicesQueriesRegistry, Client client, IndexReader reader,
+            LongSupplier nowInMillis) {
         this.mapperService = mapperService;
         this.scriptService = scriptService;
         this.indexSettings = indexSettings;
+        this.xContentRegistry = xContentRegistry;
         this.indicesQueriesRegistry = indicesQueriesRegistry;
         this.client = client;
         this.reader = reader;
@@ -92,6 +95,13 @@ public class QueryRewriteContext implements ParseFieldMatcherSupplier {
         return this.indexSettings.getParseFieldMatcher();
     }
 
+    /**
+     * The registry used to build new {@link XContentParser}s. Contains registered named parsers needed to parse the query.
+     */
+    public NamedXContentRegistry getXContentRegistry() {
+        return xContentRegistry;
+    }
+
     /**
      * Returns a new {@link QueryParseContext} that wraps the provided parser, using the ParseFieldMatcher settings that
      * are configured in the index settings. The default script language will always default to Painless.

core/src/main/java/org/elasticsearch/index/query/QueryShardContext.java

@@ -33,6 +33,7 @@ import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.lucene.search.Queries;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.analysis.IndexAnalyzers;
@@ -98,10 +99,10 @@ public class QueryShardContext extends QueryRewriteContext {
     private boolean isFilter;
 
     public QueryShardContext(int shardId, IndexSettings indexSettings, BitsetFilterCache bitsetFilterCache,
-                             IndexFieldDataService indexFieldDataService, MapperService mapperService, SimilarityService similarityService,
-                             ScriptService scriptService, final IndicesQueriesRegistry indicesQueriesRegistry, Client client,
-                             IndexReader reader, LongSupplier nowInMillis) {
-        super(indexSettings, mapperService, scriptService, indicesQueriesRegistry, client, reader, nowInMillis);
+            IndexFieldDataService indexFieldDataService, MapperService mapperService, SimilarityService similarityService,
+            ScriptService scriptService, NamedXContentRegistry xContentRegistry, IndicesQueriesRegistry indicesQueriesRegistry,
+            Client client, IndexReader reader, LongSupplier nowInMillis) {
+        super(indexSettings, mapperService, scriptService, xContentRegistry, indicesQueriesRegistry, client, reader, nowInMillis);
         this.shardId = shardId;
         this.indexSettings = indexSettings;
         this.similarityService = similarityService;
@@ -116,7 +117,7 @@ public class QueryShardContext extends QueryRewriteContext {
 
     public QueryShardContext(QueryShardContext source) {
         this(source.shardId, source.indexSettings, source.bitsetFilterCache, source.indexFieldDataService, source.mapperService,
-                source.similarityService, source.scriptService, source.indicesQueriesRegistry, source.client,
+                source.similarityService, source.scriptService, source.getXContentRegistry(), source.indicesQueriesRegistry, source.client,
                 source.reader, source.nowInMillis);
         this.types = source.getTypes();
     }

core/src/main/java/org/elasticsearch/index/query/WrapperQueryBuilder.java

@@ -160,7 +160,7 @@ public class WrapperQueryBuilder extends AbstractQueryBuilder<WrapperQueryBuilde
 
     @Override
     protected QueryBuilder doRewrite(QueryRewriteContext context) throws IOException {
-        try (XContentParser qSourceParser = XContentFactory.xContent(source).createParser(source)) {
+        try (XContentParser qSourceParser = XContentFactory.xContent(source).createParser(context.getXContentRegistry(), source)) {
             QueryParseContext parseContext = context.newParseContext(qSourceParser);
 
             final QueryBuilder queryBuilder = parseContext.parseInnerQueryBuilder();

core/src/main/java/org/elasticsearch/index/query/functionscore/DecayFunctionBuilder.java

@@ -34,6 +34,7 @@ import org.elasticsearch.common.lucene.search.function.LeafScoreFunction;
 import org.elasticsearch.common.lucene.search.function.ScoreFunction;
 import org.elasticsearch.common.unit.DistanceUnit;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -145,10 +146,7 @@ public abstract class DecayFunctionBuilder<DFB extends DecayFunctionBuilder<DFB>
     @Override
     public void doXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(getName());
-        builder.field(fieldName);
-        try (XContentParser parser = XContentFactory.xContent(functionBytes).createParser(functionBytes)) {
-            builder.copyCurrentStructure(parser);
-        }
+        builder.rawField(fieldName, functionBytes);
         builder.field(DecayFunctionParser.MULTI_VALUE_MODE.getPreferredName(), multiValueMode.name());
         builder.endObject();
     }
@@ -181,7 +179,8 @@ public abstract class DecayFunctionBuilder<DFB extends DecayFunctionBuilder<DFB>
     @Override
     protected ScoreFunction doToFunction(QueryShardContext context) throws IOException {
         AbstractDistanceScoreFunction scoreFunction;
-        try (XContentParser parser = XContentFactory.xContent(functionBytes).createParser(functionBytes)) {
+        // EMPTY is safe because parseVariable doesn't use namedObject
+        try (XContentParser parser = XContentFactory.xContent(functionBytes).createParser(NamedXContentRegistry.EMPTY, functionBytes)) {
             scoreFunction = parseVariable(fieldName, parser, context, multiValueMode);
         }
         return scoreFunction;

core/src/main/java/org/elasticsearch/index/query/functionscore/FunctionScoreQueryBuilder.java

@@ -31,7 +31,6 @@ import org.elasticsearch.common.lucene.search.function.FiltersFunctionScoreQuery
 import org.elasticsearch.common.lucene.search.function.FiltersFunctionScoreQuery.FilterFunction;
 import org.elasticsearch.common.lucene.search.function.FunctionScoreQuery;
 import org.elasticsearch.common.lucene.search.function.ScoreFunction;
-import org.elasticsearch.common.xcontent.ParseFieldRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentLocation;
@@ -436,8 +435,7 @@ public class FunctionScoreQueryBuilder extends AbstractQueryBuilder<FunctionScor
         InnerHitBuilder.extractInnerHits(query(), innerHits);
     }
 
-    public static FunctionScoreQueryBuilder fromXContent(ParseFieldRegistry<ScoreFunctionParser<?>> scoreFunctionsRegistry,
-            QueryParseContext parseContext) throws IOException {
+    public static FunctionScoreQueryBuilder fromXContent(QueryParseContext parseContext) throws IOException {
         XContentParser parser = parseContext.parser();
 
         QueryBuilder query = null;
@@ -481,11 +479,8 @@ public class FunctionScoreQueryBuilder extends AbstractQueryBuilder<FunctionScor
                     singleFunctionFound = true;
                     singleFunctionName = currentFieldName;
 
-                    // we try to parse a score function. If there is no score function for the current field name,
-                    // getScoreFunction will throw.
-                    ScoreFunctionBuilder<?> scoreFunction = scoreFunctionsRegistry
-                            .lookup(currentFieldName, parseContext.getParseFieldMatcher(), parser.getTokenLocation())
-                            .fromXContent(parseContext);
+                        ScoreFunctionBuilder<?> scoreFunction = parser.namedObject(ScoreFunctionBuilder.class, currentFieldName,
+                                parseContext);
                     filterFunctionBuilders.add(new FunctionScoreQueryBuilder.FilterFunctionBuilder(scoreFunction));
                 }
             } else if (token == XContentParser.Token.START_ARRAY) {
@@ -495,7 +490,7 @@ public class FunctionScoreQueryBuilder extends AbstractQueryBuilder<FunctionScor
                         handleMisplacedFunctionsDeclaration(parser.getTokenLocation(), errorString);
                     }
                     functionArrayFound = true;
-                    currentFieldName = parseFiltersAndFunctions(scoreFunctionsRegistry, parseContext, filterFunctionBuilders);
+                    currentFieldName = parseFiltersAndFunctions(parseContext, filterFunctionBuilders);
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), "failed to parse [{}] query. array [{}] is not supported",
                             NAME, currentFieldName);
@@ -562,9 +557,8 @@ public class FunctionScoreQueryBuilder extends AbstractQueryBuilder<FunctionScor
                 MISPLACED_FUNCTION_MESSAGE_PREFIX + errorString);
     }
 
-    private static String parseFiltersAndFunctions(ParseFieldRegistry<ScoreFunctionParser<?>> scoreFunctionsRegistry,
-            QueryParseContext parseContext, List<FunctionScoreQueryBuilder.FilterFunctionBuilder> filterFunctionBuilders)
-                    throws IOException {
+    private static String parseFiltersAndFunctions(QueryParseContext parseContext,
+            List<FunctionScoreQueryBuilder.FilterFunctionBuilder> filterFunctionBuilders) throws IOException {
         String currentFieldName = null;
         XContentParser.Token token;
         XContentParser parser = parseContext.parser();
@@ -589,8 +583,7 @@ public class FunctionScoreQueryBuilder extends AbstractQueryBuilder<FunctionScor
                                         "failed to parse function_score functions. already found [{}], now encountering [{}].",
                                         scoreFunction.getName(), currentFieldName);
                             }
-                            scoreFunction = scoreFunctionsRegistry.lookup(currentFieldName, parseContext.getParseFieldMatcher(),
-                                    parser.getTokenLocation()).fromXContent(parseContext);
+                            scoreFunction = parser.namedObject(ScoreFunctionBuilder.class, currentFieldName, parseContext);
                         }
                     } else if (token.isValue()) {
                         if (parseContext.getParseFieldMatcher().match(currentFieldName, WEIGHT_FIELD)) {

core/src/main/java/org/elasticsearch/index/shard/CommitPoints.java

@@ -21,6 +21,7 @@ package org.elasticsearch.index.shard;
 
 import org.apache.lucene.util.CollectionUtil;
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -118,7 +119,8 @@ public class CommitPoints implements Iterable<CommitPoint> {
     }
 
     public static CommitPoint fromXContent(byte[] data) throws Exception {
-        try (XContentParser parser = XContentFactory.xContent(XContentType.JSON).createParser(data)) {
+        // EMPTY is safe here because we never call namedObject
+        try (XContentParser parser = XContentFactory.xContent(XContentType.JSON).createParser(NamedXContentRegistry.EMPTY, data)) {
             String currentFieldName = null;
             XContentParser.Token token = parser.nextToken();
             if (token == null) {

core/src/main/java/org/elasticsearch/index/translog/TruncateTranslogCommand.java

@@ -34,10 +34,11 @@ import org.apache.lucene.store.OutputStreamDataOutput;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
 import org.elasticsearch.ElasticsearchException;
-import org.elasticsearch.cli.SettingCommand;
+import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.common.SuppressForbidden;
 import org.elasticsearch.common.io.PathUtils;
+import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.seqno.SequenceNumbersService;
 
@@ -55,7 +56,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-public class TruncateTranslogCommand extends SettingCommand {
+public class TruncateTranslogCommand extends EnvironmentAwareCommand {
 
     private final OptionSpec<String> translogFolder;
     private final OptionSpec<Void> batchMode;
@@ -87,7 +88,7 @@ public class TruncateTranslogCommand extends SettingCommand {
     }
 
     @Override
-    protected void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws Exception {
+    protected void execute(Terminal terminal, OptionSet options, Environment env) throws Exception {
         boolean batch = options.has(batchMode);
 
         Path translogPath = getTranslogPath(options);

core/src/main/java/org/elasticsearch/indices/IndicesService.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.indices;
 
 import com.carrotsearch.hppc.cursors.ObjectCursor;
+
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.apache.lucene.index.DirectoryReader;
@@ -68,6 +69,8 @@ import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.Callback;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
 import org.elasticsearch.common.util.iterable.Iterables;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.env.ShardLock;
@@ -133,7 +136,6 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
-import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -151,6 +153,7 @@ public class IndicesService extends AbstractLifecycleComponent
         Setting.positiveTimeSetting("indices.cache.cleanup_interval", TimeValue.timeValueMinutes(1), Property.NodeScope);
     private final PluginsService pluginsService;
     private final NodeEnvironment nodeEnv;
+    private final NamedXContentRegistry xContentRegistry;
     private final TimeValue shardsClosedTimeout;
     private final AnalysisRegistry analysisRegistry;
     private final IndicesQueriesRegistry indicesQueriesRegistry;
@@ -182,7 +185,7 @@ public class IndicesService extends AbstractLifecycleComponent
         threadPool.schedule(this.cleanInterval, ThreadPool.Names.SAME, this.cacheCleaner);
     }
 
-    public IndicesService(Settings settings, PluginsService pluginsService, NodeEnvironment nodeEnv,
+    public IndicesService(Settings settings, PluginsService pluginsService, NodeEnvironment nodeEnv, NamedXContentRegistry xContentRegistry,
                           ClusterSettings clusterSettings, AnalysisRegistry analysisRegistry,
                           IndicesQueriesRegistry indicesQueriesRegistry, IndexNameExpressionResolver indexNameExpressionResolver,
                           MapperRegistry mapperRegistry, NamedWriteableRegistry namedWriteableRegistry,
@@ -193,6 +196,7 @@ public class IndicesService extends AbstractLifecycleComponent
         this.threadPool = threadPool;
         this.pluginsService = pluginsService;
         this.nodeEnv = nodeEnv;
+        this.xContentRegistry = xContentRegistry;
         this.shardsClosedTimeout = settings.getAsTime(INDICES_SHARDS_CLOSED_TIMEOUT, new TimeValue(1, TimeUnit.DAYS));
         this.analysisRegistry = analysisRegistry;
         this.indicesQueriesRegistry = indicesQueriesRegistry;
@@ -441,6 +445,7 @@ public class IndicesService extends AbstractLifecycleComponent
         }
         return indexModule.newIndexService(
             nodeEnv,
+            xContentRegistry,
             this,
             circuitBreakerService,
             bigArrays,
@@ -465,7 +470,7 @@ public class IndicesService extends AbstractLifecycleComponent
         final IndexSettings idxSettings = new IndexSettings(indexMetaData, this.settings, indexScopeSetting);
         final IndexModule indexModule = new IndexModule(idxSettings, analysisRegistry);
         pluginsService.onIndexModule(indexModule);
-        return indexModule.newIndexMapperService(mapperRegistry);
+        return indexModule.newIndexMapperService(xContentRegistry, mapperRegistry);
     }
 
     /**
@@ -1259,11 +1264,16 @@ public class IndicesService extends AbstractLifecycleComponent
     private final IndexDeletionAllowedPredicate ALWAYS_TRUE = (Index index, IndexSettings indexSettings) -> true;
 
     public AliasFilter buildAliasFilter(ClusterState state, String index, String... expressions) {
-        Function<XContentParser, QueryParseContext> factory =
-            (parser) -> new QueryParseContext(indicesQueriesRegistry, parser, new ParseFieldMatcher(settings));
+        /* Being static, parseAliasFilter doesn't have access to whatever guts it needs to parse a query. Instead of passing in a bunch
+         * of dependencies we pass in a function that can perform the parsing. */
+        ShardSearchRequest.FilterParser filterParser = bytes -> {
+            try (XContentParser parser = XContentFactory.xContent(bytes).createParser(xContentRegistry, bytes)) {
+                return new QueryParseContext(indicesQueriesRegistry, parser, new ParseFieldMatcher(settings)).parseInnerQueryBuilder();
+            }
+        };
         String[] aliases = indexNameExpressionResolver.filteringAliases(state, index, expressions);
         IndexMetaData indexMetaData = state.metaData().index(index);
-        return new AliasFilter(ShardSearchRequest.parseAliasFilter(factory, indexMetaData, aliases), aliases);
+        return new AliasFilter(ShardSearchRequest.parseAliasFilter(filterParser, indexMetaData, aliases), aliases);
     }
 
 }

core/src/main/java/org/elasticsearch/indices/recovery/PeerRecoveryTargetService.java

@@ -397,21 +397,21 @@ public class PeerRecoveryTargetService extends AbstractComponent implements Inde
     }
 
     private void waitForClusterState(long clusterStateVersion) {
-        ClusterStateObserver observer = new ClusterStateObserver(clusterService, TimeValue.timeValueMinutes(5), logger,
+        final ClusterState clusterState = clusterService.state();
+        ClusterStateObserver observer = new ClusterStateObserver(clusterState, clusterService, TimeValue.timeValueMinutes(5), logger,
             threadPool.getThreadContext());
-        final ClusterState clusterState = observer.observedState();
         if (clusterState.getVersion() >= clusterStateVersion) {
             logger.trace("node has cluster state with version higher than {} (current: {})", clusterStateVersion,
                 clusterState.getVersion());
             return;
         } else {
             logger.trace("waiting for cluster state version {} (current: {})", clusterStateVersion, clusterState.getVersion());
-            final PlainActionFuture<Void> future = new PlainActionFuture<>();
+            final PlainActionFuture<Long> future = new PlainActionFuture<>();
             observer.waitForNextChange(new ClusterStateObserver.Listener() {
 
                 @Override
                 public void onNewClusterState(ClusterState state) {
-                    future.onResponse(null);
+                    future.onResponse(state.getVersion());
                 }
 
                 @Override
@@ -425,15 +425,14 @@ public class PeerRecoveryTargetService extends AbstractComponent implements Inde
                 }
             }, newState -> newState.getVersion() >= clusterStateVersion);
             try {
-                future.get();
-                logger.trace("successfully waited for cluster state with version {} (current: {})", clusterStateVersion,
-                    observer.observedState().getVersion());
+                long currentVersion = future.get();
+                logger.trace("successfully waited for cluster state with version {} (current: {})", clusterStateVersion, currentVersion);
             } catch (Exception e) {
                 logger.debug(
                     (Supplier<?>) () -> new ParameterizedMessage(
                         "failed waiting for cluster state with version {} (current: {})",
                         clusterStateVersion,
-                        observer.observedState().getVersion()),
+                        clusterService.state().getVersion()),
                     e);
                 throw ExceptionsHelper.convertToRuntime(e);
             }

core/src/main/java/org/elasticsearch/ingest/IngestDocument.java

@@ -145,8 +145,24 @@ public final class IngestDocument {
      * or if the field that is found at the provided path is not of the expected type.
      */
     public byte[] getFieldValueAsBytes(String path) {
-        Object object = getFieldValue(path, Object.class);
-        if (object instanceof byte[]) {
+        return getFieldValueAsBytes(path, false);
+    }
+
+    /**
+     * Returns the value contained in the document for the provided path as a byte array.
+     * If the path value is a string, a base64 decode operation will happen.
+     * If the path value is a byte array, it is just returned
+     * @param path The path within the document in dot-notation
+     * @param ignoreMissing The flag to determine whether to throw an exception when `path` is not found in the document.
+     * @return the byte array for the provided path if existing
+     * @throws IllegalArgumentException if the path is null, empty, invalid, if the field doesn't exist
+     * or if the field that is found at the provided path is not of the expected type.
+     */
+    public byte[] getFieldValueAsBytes(String path, boolean ignoreMissing) {
+        Object object = getFieldValue(path, Object.class, ignoreMissing);
+        if (object == null) {
+            return null;
+        } else if (object instanceof byte[]) {
             return (byte[]) object;
         } else if (object instanceof String) {
             return Base64.getDecoder().decode(object.toString());

core/src/main/java/org/elasticsearch/ingest/PipelineStore.java

@@ -41,9 +41,11 @@ import org.elasticsearch.common.xcontent.XContentHelper;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 
 public class PipelineStore extends AbstractComponent implements ClusterStateApplier {
 
@@ -111,17 +113,26 @@ public class PipelineStore extends AbstractComponent implements ClusterStateAppl
             return currentState;
         }
         Map<String, PipelineConfiguration> pipelines = currentIngestMetadata.getPipelines();
-        if (pipelines.containsKey(request.getId()) == false) {
-            throw new ResourceNotFoundException("pipeline [{}] is missing", request.getId());
-        } else {
-            pipelines = new HashMap<>(pipelines);
-            pipelines.remove(request.getId());
-            ClusterState.Builder newState = ClusterState.builder(currentState);
-            newState.metaData(MetaData.builder(currentState.getMetaData())
-                    .putCustom(IngestMetadata.TYPE, new IngestMetadata(pipelines))
-                    .build());
-            return newState.build();
+        Set<String> toRemove = new HashSet<>();
+        for (String pipelineKey : pipelines.keySet()) {
+            if (Regex.simpleMatch(request.getId(), pipelineKey)) {
+                toRemove.add(pipelineKey);
+            }
         }
+        if (toRemove.isEmpty() && Regex.isMatchAllPattern(request.getId()) == false) {
+            throw new ResourceNotFoundException("pipeline [{}] is missing", request.getId());
+        } else if (toRemove.isEmpty()) {
+            return currentState;
+        }
+        final Map<String, PipelineConfiguration> pipelinesCopy = new HashMap<>(pipelines);
+        for (String key : toRemove) {
+            pipelinesCopy.remove(key);
+        }
+        ClusterState.Builder newState = ClusterState.builder(currentState);
+        newState.metaData(MetaData.builder(currentState.getMetaData())
+                .putCustom(IngestMetadata.TYPE, new IngestMetadata(pipelinesCopy))
+                .build());
+        return newState.build();
     }
 
     /**

core/src/main/java/org/elasticsearch/node/Node.java

@@ -74,6 +74,7 @@ import org.elasticsearch.common.transport.BoundTransportAddress;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.BigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.discovery.Discovery;
 import org.elasticsearch.discovery.DiscoveryModule;
 import org.elasticsearch.discovery.DiscoverySettings;
@@ -159,6 +160,8 @@ import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import static java.util.stream.Collectors.toList;
+
 /**
  * A node represent a node within a cluster (<tt>cluster.name</tt>). The {@link #client()} can be used
  * in order to use a {@link Client} to perform actions/operations against the cluster.
@@ -362,8 +365,13 @@ public class Node implements Closeable {
                     .flatMap(p -> p.getNamedWriteables().stream()))
                 .flatMap(Function.identity()).collect(Collectors.toList());
             final NamedWriteableRegistry namedWriteableRegistry = new NamedWriteableRegistry(namedWriteables);
+            NamedXContentRegistry xContentRegistry = new NamedXContentRegistry(Stream.of(
+                    searchModule.getNamedXContents().stream(),
+                    pluginsService.filterPlugins(Plugin.class).stream()
+                            .flatMap(p -> p.getNamedXContent().stream())
+                    ).flatMap(Function.identity()).collect(toList()));
             final MetaStateService metaStateService = new MetaStateService(settings, nodeEnvironment);
-            final IndicesService indicesService = new IndicesService(settings, pluginsService, nodeEnvironment,
+            final IndicesService indicesService = new IndicesService(settings, pluginsService, nodeEnvironment, xContentRegistry,
                 settingsModule.getClusterSettings(), analysisModule.getAnalysisRegistry(), searchModule.getQueryParserRegistry(),
                 clusterModule.getIndexNameExpressionResolver(), indicesModule.getMapperRegistry(), namedWriteableRegistry,
                 threadPool, settingsModule.getIndexScopedSettings(), circuitBreakerService, bigArrays, scriptModule.getScriptService(),
@@ -371,14 +379,15 @@ public class Node implements Closeable {
 
             Collection<Object> pluginComponents = pluginsService.filterPlugins(Plugin.class).stream()
                 .flatMap(p -> p.createComponents(client, clusterService, threadPool, resourceWatcherService,
-                                                 scriptModule.getScriptService(), searchModule.getSearchRequestParsers()).stream())
+                                                 scriptModule.getScriptService(), searchModule.getSearchRequestParsers(),
+                                                 xContentRegistry).stream())
                 .collect(Collectors.toList());
             Collection<UnaryOperator<Map<String, MetaData.Custom>>> customMetaDataUpgraders =
                 pluginsService.filterPlugins(Plugin.class).stream()
                 .map(Plugin::getCustomMetaDataUpgrader)
                 .collect(Collectors.toList());
-            final NetworkModule networkModule = new NetworkModule(settings, false, pluginsService.filterPlugins(NetworkPlugin.class), threadPool,
-                bigArrays, circuitBreakerService, namedWriteableRegistry, networkService);
+            final NetworkModule networkModule = new NetworkModule(settings, false, pluginsService.filterPlugins(NetworkPlugin.class),
+                    threadPool, bigArrays, circuitBreakerService, namedWriteableRegistry, xContentRegistry, networkService);
             final MetaDataUpgrader metaDataUpgrader = new MetaDataUpgrader(customMetaDataUpgraders);
             final Transport transport = networkModule.getTransportSupplier().get();
             final TransportService transportService = newTransportService(settings, transport, threadPool,
@@ -404,6 +413,7 @@ public class Node implements Closeable {
                     b.bind(IndicesQueriesRegistry.class).toInstance(searchModule.getQueryParserRegistry());
                     b.bind(SearchRequestParsers.class).toInstance(searchModule.getSearchRequestParsers());
                     b.bind(SearchExtRegistry.class).toInstance(searchModule.getSearchExtRegistry());
+                    b.bind(NamedXContentRegistry.class).toInstance(xContentRegistry);
                     b.bind(PluginsService.class).toInstance(pluginsService);
                     b.bind(Client.class).toInstance(client);
                     b.bind(NodeClient.class).toInstance(client);
@@ -432,7 +442,7 @@ public class Node implements Closeable {
                     b.bind(AllocationCommandRegistry.class).toInstance(NetworkModule.getAllocationCommandRegistry());
                     b.bind(UpdateHelper.class).toInstance(new UpdateHelper(settings, scriptModule.getScriptService()));
                     b.bind(MetaDataIndexUpgradeService.class).toInstance(new MetaDataIndexUpgradeService(settings,
-                        indicesModule.getMapperRegistry(), settingsModule.getIndexScopedSettings()));
+                        xContentRegistry, indicesModule.getMapperRegistry(), settingsModule.getIndexScopedSettings()));
                     b.bind(ClusterInfoService.class).toInstance(clusterInfoService);
                     b.bind(Discovery.class).toInstance(discoveryModule.getDiscovery());
                     {
@@ -589,8 +599,9 @@ public class Node implements Closeable {
         final TimeValue initialStateTimeout = DiscoverySettings.INITIAL_STATE_TIMEOUT_SETTING.get(settings);
         if (initialStateTimeout.millis() > 0) {
             final ThreadPool thread = injector.getInstance(ThreadPool.class);
-            ClusterStateObserver observer = new ClusterStateObserver(clusterService, null, logger, thread.getThreadContext());
-            if (observer.observedState().nodes().getMasterNodeId() == null) {
+            ClusterState clusterState = clusterService.state();
+            ClusterStateObserver observer = new ClusterStateObserver(clusterState, clusterService, null, logger, thread.getThreadContext());
+            if (clusterState.nodes().getMasterNodeId() == null) {
                 logger.debug("waiting to join the cluster. timeout [{}]", initialStateTimeout);
                 final CountDownLatch latch = new CountDownLatch(1);
                 observer.waitForNextChange(new ClusterStateObserver.Listener() {

core/src/main/java/org/elasticsearch/plugins/InstallPluginCommand.java

@@ -27,7 +27,7 @@ import org.apache.lucene.util.IOUtils;
 import org.elasticsearch.Version;
 import org.elasticsearch.bootstrap.JarHell;
 import org.elasticsearch.cli.ExitCodes;
-import org.elasticsearch.cli.SettingCommand;
+import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.cli.UserException;
 import org.elasticsearch.common.collect.Tuple;
@@ -103,7 +103,7 @@ import static org.elasticsearch.cli.Terminal.Verbosity.VERBOSE;
  * elasticsearch config directory, using the name of the plugin. If any files to be installed
  * already exist, they will be skipped.
  */
-class InstallPluginCommand extends SettingCommand {
+class InstallPluginCommand extends EnvironmentAwareCommand {
 
     private static final String PROPERTY_STAGING_ID = "es.plugins.staging";
 
@@ -189,18 +189,17 @@ class InstallPluginCommand extends SettingCommand {
     }
 
     @Override
-    protected void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws Exception {
+    protected void execute(Terminal terminal, OptionSet options, Environment env) throws Exception {
         String pluginId = arguments.value(options);
         boolean isBatch = options.has(batchOption) || System.console() == null;
-        execute(terminal, pluginId, isBatch, settings);
+        execute(terminal, pluginId, isBatch, env);
     }
 
     // pkg private for testing
-    void execute(Terminal terminal, String pluginId, boolean isBatch, Map<String, String> settings) throws Exception {
+    void execute(Terminal terminal, String pluginId, boolean isBatch, Environment env) throws Exception {
         if (pluginId == null) {
             throw new UserException(ExitCodes.USAGE, "plugin id is required");
         }
-        final Environment env = InternalSettingsPreparer.prepareEnvironment(Settings.EMPTY, terminal, settings);
         // TODO: remove this leniency!! is it needed anymore?
         if (Files.exists(env.pluginsFile()) == false) {
             terminal.println("Plugins directory [" + env.pluginsFile() + "] does not exist. Creating...");

core/src/main/java/org/elasticsearch/plugins/ListPluginsCommand.java

@@ -20,7 +20,7 @@
 package org.elasticsearch.plugins;
 
 import joptsimple.OptionSet;
-import org.elasticsearch.cli.SettingCommand;
+import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
@@ -38,15 +38,14 @@ import java.util.Map;
 /**
  * A command for the plugin cli to list plugins installed in elasticsearch.
  */
-class ListPluginsCommand extends SettingCommand {
+class ListPluginsCommand extends EnvironmentAwareCommand {
 
     ListPluginsCommand() {
         super("Lists installed elasticsearch plugins");
     }
 
     @Override
-    protected void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws Exception {
-        final Environment env = InternalSettingsPreparer.prepareEnvironment(Settings.EMPTY, terminal, settings);
+    protected void execute(Terminal terminal, OptionSet options, Environment env) throws Exception {
         if (Files.exists(env.pluginsFile()) == false) {
             throw new IOException("Plugins directory missing: " + env.pluginsFile());
         }

core/src/main/java/org/elasticsearch/plugins/NetworkPlugin.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.network.NetworkService;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.BigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.http.HttpServerTransport;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -62,9 +63,8 @@ public interface NetworkPlugin {
      * See {@link org.elasticsearch.common.network.NetworkModule#HTTP_TYPE_SETTING} to configure a specific implementation.
      */
     default Map<String, Supplier<HttpServerTransport>> getHttpTransports(Settings settings, ThreadPool threadPool, BigArrays bigArrays,
-                                                               CircuitBreakerService circuitBreakerService,
-                                                               NamedWriteableRegistry namedWriteableRegistry,
-                                                               NetworkService networkService) {
+            CircuitBreakerService circuitBreakerService, NamedWriteableRegistry namedWriteableRegistry,
+            NamedXContentRegistry xContentRegistry, NetworkService networkService) {
         return Collections.emptyMap();
     }
 }

core/src/main/java/org/elasticsearch/plugins/Plugin.java

@@ -19,12 +19,6 @@
 
 package org.elasticsearch.plugins;
 
-import java.io.Closeable;
-import java.io.IOException;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-
 import org.elasticsearch.action.ActionModule;
 import org.elasticsearch.bootstrap.BootstrapCheck;
 import org.elasticsearch.client.Client;
@@ -39,6 +33,8 @@ import org.elasticsearch.common.network.NetworkModule;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.settings.SettingsModule;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.discovery.DiscoveryModule;
 import org.elasticsearch.index.IndexModule;
 import org.elasticsearch.indices.analysis.AnalysisModule;
@@ -51,6 +47,11 @@ import org.elasticsearch.threadpool.ExecutorBuilder;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.watcher.ResourceWatcherService;
 
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.function.UnaryOperator;
 
@@ -106,7 +107,7 @@ public abstract class Plugin implements Closeable {
      */
     public Collection<Object> createComponents(Client client, ClusterService clusterService, ThreadPool threadPool,
                                                ResourceWatcherService resourceWatcherService, ScriptService scriptService,
-                                               SearchRequestParsers searchRequestParsers) {
+                                               SearchRequestParsers searchRequestParsers, NamedXContentRegistry xContentRegistry) {
         return Collections.emptyList();
     }
 
@@ -126,6 +127,14 @@ public abstract class Plugin implements Closeable {
         return Collections.emptyList();
     }
 
+    /**
+     * Returns parsers for named objects this plugin will parse from {@link XContentParser#namedObject(Class, String, Object)}.
+     * @see NamedWriteableRegistry
+     */
+    public List<NamedXContentRegistry.Entry> getNamedXContent() {
+        return Collections.emptyList();
+    }
+
     /**
      * Called before a new index is created on a node. The given module can be used to register index-level
      * extensions.

core/src/main/java/org/elasticsearch/plugins/RemovePluginCommand.java

@@ -19,32 +19,28 @@
 
 package org.elasticsearch.plugins;
 
-import joptsimple.OptionSet;
-import joptsimple.OptionSpec;
-
-import org.apache.lucene.util.IOUtils;
-import org.elasticsearch.cli.ExitCodes;
-import org.elasticsearch.cli.SettingCommand;
-import org.elasticsearch.cli.Terminal;
-import org.elasticsearch.cli.UserException;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.env.Environment;
-import org.elasticsearch.node.internal.InternalSettingsPreparer;
-
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
+
+import joptsimple.OptionSet;
+import joptsimple.OptionSpec;
+import org.apache.lucene.util.IOUtils;
+import org.elasticsearch.cli.EnvironmentAwareCommand;
+import org.elasticsearch.cli.ExitCodes;
+import org.elasticsearch.cli.Terminal;
+import org.elasticsearch.cli.UserException;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.env.Environment;
 
 import static org.elasticsearch.cli.Terminal.Verbosity.VERBOSE;
 
 /**
  * A command for the plugin cli to remove a plugin from elasticsearch.
  */
-class RemovePluginCommand extends SettingCommand {
+class RemovePluginCommand extends EnvironmentAwareCommand {
 
     private final OptionSpec<String> arguments;
 
@@ -54,15 +50,13 @@ class RemovePluginCommand extends SettingCommand {
     }
 
     @Override
-    protected void execute(Terminal terminal, OptionSet options, Map<String, String> settings) throws Exception {
+    protected void execute(Terminal terminal, OptionSet options, Environment env) throws Exception {
         String arg = arguments.value(options);
-        execute(terminal, arg, settings);
+        execute(terminal, arg, env);
     }
 
     // pkg private for testing
-    void execute(Terminal terminal, String pluginName, Map<String, String> settings) throws Exception {
-        final Environment env = InternalSettingsPreparer.prepareEnvironment(Settings.EMPTY, terminal, settings);
-
+    void execute(Terminal terminal, String pluginName, Environment env) throws Exception {
         terminal.println("-> Removing " + Strings.coalesceToEmpty(pluginName) + "...");
 
         final Path pluginDir = env.pluginsFile().resolve(pluginName);

core/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreFormat.java

@@ -23,6 +23,7 @@ import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.blobstore.BlobContainer;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.xcontent.FromXContentBuilder;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -109,10 +110,10 @@ public abstract class BlobStoreFormat<T extends ToXContent> {
     }
 
     protected T read(BytesReference bytes) throws IOException {
-        try (XContentParser parser = XContentHelper.createParser(bytes)) {
+        // EMPTY is safe here because no reader calls namedObject
+        try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, bytes)) {
             T obj = reader.fromXContent(parser, parseFieldMatcher);
             return obj;
-
         }
     }
 

core/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java

@@ -68,6 +68,7 @@ import org.elasticsearch.common.unit.ByteSizeUnit;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.util.iterable.Iterables;
 import org.elasticsearch.common.util.set.Sets;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
@@ -625,7 +626,8 @@ public abstract class BlobStoreRepository extends AbstractLifecycleComponent imp
             try (InputStream blob = snapshotsBlobContainer.readBlob(snapshotsIndexBlobName)) {
                 BytesStreamOutput out = new BytesStreamOutput();
                 Streams.copy(blob, out);
-                try (XContentParser parser = XContentHelper.createParser(out.bytes())) {
+                // EMPTY is safe here because RepositoryData#fromXContent calls namedObject
+                try (XContentParser parser = XContentHelper.createParser(NamedXContentRegistry.EMPTY, out.bytes())) {
                     repositoryData = RepositoryData.fromXContent(parser);
                 }
             }

core/src/main/java/org/elasticsearch/rest/RestRequest.java

@@ -28,6 +28,7 @@ import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -46,11 +47,13 @@ import static org.elasticsearch.common.unit.TimeValue.parseTimeValue;
 
 public abstract class RestRequest implements ToXContent.Params {
 
+    private final NamedXContentRegistry xContentRegistry;
     private final Map<String, String> params;
     private final String rawPath;
     private final Set<String> consumedParams = new HashSet<>();
 
-    public RestRequest(String uri) {
+    public RestRequest(NamedXContentRegistry xContentRegistry, String uri) {
+        this.xContentRegistry = xContentRegistry;
         final Map<String, String> params = new HashMap<>();
         int pathEndPos = uri.indexOf('?');
         if (pathEndPos < 0) {
@@ -62,7 +65,8 @@ public abstract class RestRequest implements ToXContent.Params {
         this.params = params;
     }
 
-    public RestRequest(Map<String, String> params, String path) {
+    public RestRequest(NamedXContentRegistry xContentRegistry, Map<String, String> params, String path) {
+        this.xContentRegistry = xContentRegistry;
         this.params = params;
         this.rawPath = path;
     }
@@ -228,6 +232,13 @@ public abstract class RestRequest implements ToXContent.Params {
         return params;
     }
 
+    /**
+     * Get the {@link NamedXContentRegistry} that should be used to create parsers from this request.
+     */
+    public NamedXContentRegistry getXContentRegistry() {
+        return xContentRegistry;
+    }
+
     /**
      * A parser for the contents of this request if there is a body, otherwise throws an {@link ElasticsearchParseException}. Use
      * {@link #applyContentParser(CheckedConsumer)} if you want to gracefully handle when the request doesn't have any contents. Use
@@ -238,7 +249,7 @@ public abstract class RestRequest implements ToXContent.Params {
         if (content.length() == 0) {
             throw new ElasticsearchParseException("Body required");
         }
-        return XContentFactory.xContent(content).createParser(content);
+        return XContentFactory.xContent(content).createParser(xContentRegistry, content);
     }
 
     /**
@@ -270,7 +281,7 @@ public abstract class RestRequest implements ToXContent.Params {
         if (content.length() == 0) {
             throw new ElasticsearchParseException("Body required");
         }
-        return XContentFactory.xContent(content).createParser(content);
+        return XContentFactory.xContent(content).createParser(xContentRegistry, content);
     }
 
     /**
@@ -281,7 +292,7 @@ public abstract class RestRequest implements ToXContent.Params {
     public final void withContentOrSourceParamParserOrNull(CheckedConsumer<XContentParser, IOException> withParser) throws IOException {
         BytesReference content = contentOrSourceParam();
         if (content.length() > 0) {
-            try (XContentParser parser = XContentFactory.xContent(content).createParser(content)) {
+            try (XContentParser parser = XContentFactory.xContent(content).createParser(xContentRegistry, content)) {
                 withParser.accept(parser);
             }
         } else {