Internal: Add METADATA_READ and METADATA_WRITE blocks

This commit splits the current ClusterBlockLevel.METADATA into two disctins ClusterBlockLevel.METADATA_READ and ClusterBlockLevel.METADATA_WRITE blocks. It allows to make a distinction between
an operation that modifies the index or cluster metadata and an operation that does not change any metadata.

Before this commit, many operations where blocked when the cluster was read-only: Cluster Stats, Get Mappings, Get Snapshot, Get Index Settings, etc. Now those operations are allowed even when
the cluster or the index is read-only.

Related to #8102, #2833

Closes #3703
Closes #5855
Closes #10521
Closes #10522

rest-api-spec/test/indices.exists/20_read_only_index.yaml

@@ -0,0 +1,30 @@
+---
+"Test indices.exists on a read only index":
+
+  - do:
+      indices.create:
+        index: test_index_ro
+
+  - do:
+      indices.put_settings:
+        index: test_index_ro
+        body:
+          index.blocks.read_only: true
+
+  - do:
+      indices.exists:
+        index: test_index_ro
+
+  - is_true: ''
+
+  - do:
+      indices.put_settings:
+        index: test_index_ro
+        body:
+          index.blocks.read_only: false
+
+  - do:
+      indices.exists:
+        index: test_index_ro
+
+  - is_true: ''

src/main/java/org/elasticsearch/action/admin/cluster/node/shutdown/TransportNodesShutdownAction.java

@@ -75,7 +75,8 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(NodesShutdownRequest request, ClusterState state) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        // Stopping a node impacts the cluster state, so we check for the METADATA_WRITE block here
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/repositories/delete/TransportDeleteRepositoryAction.java

@@ -65,7 +65,7 @@ protected DeleteRepositoryResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(DeleteRepositoryRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/repositories/get/TransportGetRepositoriesAction.java

@@ -65,7 +65,7 @@ protected GetRepositoriesResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(GetRepositoriesRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_READ, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/repositories/put/TransportPutRepositoryAction.java

@@ -65,7 +65,7 @@ protected PutRepositoryResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(PutRepositoryRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/repositories/verify/TransportVerifyRepositoryAction.java

@@ -69,7 +69,7 @@ protected VerifyRepositoryResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(VerifyRepositoryRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_READ, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/reroute/TransportClusterRerouteAction.java

@@ -58,7 +58,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(ClusterRerouteRequest request, ClusterState state) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/settings/TransportClusterUpdateSettingsAction.java

@@ -76,7 +76,7 @@ protected ClusterBlockException checkBlock(ClusterUpdateSettingsRequest request,
                 request.persistentSettings().getAsMap().isEmpty() && request.transientSettings().getAsMap().size() == 1 && request.transientSettings().get(MetaData.SETTING_READ_ONLY) != null) {
             return null;
         }
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
 

src/main/java/org/elasticsearch/action/admin/cluster/shards/TransportClusterSearchShardsAction.java

@@ -58,7 +58,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(ClusterSearchShardsRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/snapshots/create/TransportCreateSnapshotAction.java

@@ -65,7 +65,7 @@ protected CreateSnapshotResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(CreateSnapshotRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/snapshots/delete/TransportDeleteSnapshotAction.java

@@ -64,7 +64,7 @@ protected DeleteSnapshotResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(DeleteSnapshotRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/snapshots/get/TransportGetSnapshotsAction.java

@@ -67,7 +67,7 @@ protected GetSnapshotsResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(GetSnapshotsRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_READ, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/snapshots/restore/TransportRestoreSnapshotAction.java

@@ -65,7 +65,13 @@ protected RestoreSnapshotResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(RestoreSnapshotRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, "");
+        // Restoring a snapshot might change the global state and create/change an index,
+        // so we need to check for METADATA_WRITE and WRITE blocks
+        ClusterBlockException blockException = state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, "");
+        if (blockException != null) {
+            return blockException;
+        }
+        return state.blocks().indexBlockedException(ClusterBlockLevel.WRITE, "");
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/snapshots/status/TransportSnapshotsStatusAction.java

@@ -70,7 +70,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(SnapshotsStatusRequest request, ClusterState state) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_READ);
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/cluster/tasks/TransportPendingClusterTasksAction.java

@@ -53,7 +53,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(PendingClusterTasksRequest request, ClusterState state) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_READ);
     }
 
     @Override

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

@@ -78,7 +78,7 @@ protected ClusterBlockException checkBlock(IndicesAliasesRequest request, Cluste
                 indices.add(index);
             }
         }
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, indices.toArray(new String[indices.size()]));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, indices.toArray(new String[indices.size()]));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/alias/exists/TransportAliasesExistAction.java

@@ -49,7 +49,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(GetAliasesRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

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

@@ -52,7 +52,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(GetAliasesRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/cache/clear/TransportClearIndicesCacheAction.java

@@ -175,12 +175,12 @@ protected GroupShardsIterator shards(ClusterState clusterState, ClearIndicesCach
 
     @Override
     protected ClusterBlockException checkGlobalBlock(ClusterState state, ClearIndicesCacheRequest request) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override
     protected ClusterBlockException checkRequestBlock(ClusterState state, ClearIndicesCacheRequest request, String[] concreteIndices) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, concreteIndices);
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, concreteIndices);
     }
 
 }

src/main/java/org/elasticsearch/action/admin/indices/close/TransportCloseIndexAction.java

@@ -76,7 +76,7 @@ protected void doExecute(CloseIndexRequest request, ActionListener<CloseIndexRes
 
     @Override
     protected ClusterBlockException checkBlock(CloseIndexRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/create/TransportCreateIndexAction.java

@@ -67,7 +67,7 @@ protected CreateIndexResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(CreateIndexRequest request, ClusterState state) {
-        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA, request.index());
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_WRITE, request.index());
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/delete/TransportDeleteIndexAction.java

@@ -76,7 +76,7 @@ protected void doExecute(DeleteIndexRequest request, ActionListener<DeleteIndexR
 
     @Override
     protected ClusterBlockException checkBlock(DeleteIndexRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/exists/indices/TransportIndicesExistsAction.java

@@ -65,7 +65,7 @@ protected IndicesExistsResponse newResponse() {
     protected ClusterBlockException checkBlock(IndicesExistsRequest request, ClusterState state) {
         //make sure through indices options that the concrete indices call never throws IndexMissingException
         IndicesOptions indicesOptions = IndicesOptions.fromOptions(true, true, request.indicesOptions().expandWildcardsOpen(), request.indicesOptions().expandWildcardsClosed());
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, clusterService.state().metaData().concreteIndices(indicesOptions, request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, clusterService.state().metaData().concreteIndices(indicesOptions, request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/exists/types/TransportTypesExistsAction.java

@@ -62,7 +62,7 @@ protected TypesExistsResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(TypesExistsRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/flush/TransportFlushAction.java

@@ -120,11 +120,11 @@ protected GroupShardsIterator shards(ClusterState clusterState, FlushRequest req
 
     @Override
     protected ClusterBlockException checkGlobalBlock(ClusterState state, FlushRequest request) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override
     protected ClusterBlockException checkRequestBlock(ClusterState state, FlushRequest countRequest, String[] concreteIndices) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, concreteIndices);
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, concreteIndices);
     }
 }

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

@@ -60,7 +60,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(GetIndexRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

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

@@ -29,6 +29,8 @@
 import org.elasticsearch.action.support.single.custom.TransportSingleCustomOperationAction;
 import org.elasticsearch.cluster.ClusterService;
 import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.block.ClusterBlockException;
+import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.routing.ShardsIterator;
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.inject.Inject;
@@ -38,10 +40,10 @@
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentType;
+import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.mapper.DocumentFieldMappers;
 import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.FieldMapper;
-import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.indices.TypeMissingException;
@@ -134,6 +136,11 @@ protected GetFieldMappingsResponse newResponse() {
         return new GetFieldMappingsResponse();
     }
 
+    @Override
+    protected ClusterBlockException checkRequestBlock(ClusterState state, InternalRequest request) {
+        return state.blocks().indexBlockedException(ClusterBlockLevel.METADATA_READ, request.concreteIndex());
+    }
+
     private static final ToXContent.Params includeDefaultsParams = new ToXContent.Params() {
 
         final static String INCLUDE_DEFAULTS = "include_defaults";

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

@@ -51,7 +51,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(GetMappingsRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/mapping/put/TransportPutMappingAction.java

@@ -66,7 +66,7 @@ protected PutMappingResponse newResponse() {
 
     @Override
     protected ClusterBlockException checkBlock(PutMappingRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, clusterService.state().metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, clusterService.state().metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/open/TransportOpenIndexAction.java

@@ -76,7 +76,7 @@ protected void doExecute(OpenIndexRequest request, ActionListener<OpenIndexRespo
 
     @Override
     protected ClusterBlockException checkBlock(OpenIndexRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/optimize/TransportOptimizeAction.java

@@ -121,11 +121,11 @@ protected GroupShardsIterator shards(ClusterState clusterState, OptimizeRequest
 
     @Override
     protected ClusterBlockException checkGlobalBlock(ClusterState state, OptimizeRequest request) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override
     protected ClusterBlockException checkRequestBlock(ClusterState state, OptimizeRequest request, String[] concreteIndices) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, concreteIndices);
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, concreteIndices);
     }
 }

src/main/java/org/elasticsearch/action/admin/indices/refresh/TransportRefreshAction.java

@@ -122,11 +122,11 @@ protected GroupShardsIterator shards(ClusterState clusterState, RefreshRequest r
 
     @Override
     protected ClusterBlockException checkGlobalBlock(ClusterState state, RefreshRequest request) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_WRITE);
     }
 
     @Override
     protected ClusterBlockException checkRequestBlock(ClusterState state, RefreshRequest countRequest, String[] concreteIndices) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, concreteIndices);
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_WRITE, concreteIndices);
     }
 }

src/main/java/org/elasticsearch/action/admin/indices/segments/TransportIndicesSegmentsAction.java

@@ -83,12 +83,12 @@ protected GroupShardsIterator shards(ClusterState clusterState, IndicesSegmentsR
 
     @Override
     protected ClusterBlockException checkGlobalBlock(ClusterState state, IndicesSegmentsRequest request) {
-        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA);
+        return state.blocks().globalBlockedException(ClusterBlockLevel.METADATA_READ);
     }
 
     @Override
     protected ClusterBlockException checkRequestBlock(ClusterState state, IndicesSegmentsRequest countRequest, String[] concreteIndices) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, concreteIndices);
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, concreteIndices);
     }
 
     @Override

src/main/java/org/elasticsearch/action/admin/indices/settings/get/TransportGetSettingsAction.java

@@ -62,7 +62,7 @@ protected String executor() {
 
     @Override
     protected ClusterBlockException checkBlock(GetSettingsRequest request, ClusterState state) {
-        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
+        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ, state.metaData().concreteIndices(request.indicesOptions(), request.indices()));
     }