[CLIENT] Add internal liveness action

This commit adds a very lightweight action to the transport
serivce that allows to fetch clustername and the discovery node
from a node. This is used by transport clients to test liveness of
a node without using the nodesinfo API which can be blocking if management
threadpools are busy.

Closes #8763

src/main/java/org/elasticsearch/action/ActionModule.java

@@ -27,6 +27,7 @@ import org.elasticsearch.action.admin.cluster.node.hotthreads.NodesHotThreadsAct
 import org.elasticsearch.action.admin.cluster.node.hotthreads.TransportNodesHotThreadsAction;
 import org.elasticsearch.action.admin.cluster.node.info.NodesInfoAction;
 import org.elasticsearch.action.admin.cluster.node.info.TransportNodesInfoAction;
+import org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction;
 import org.elasticsearch.action.admin.cluster.node.restart.NodesRestartAction;
 import org.elasticsearch.action.admin.cluster.node.restart.TransportNodesRestartAction;
 import org.elasticsearch.action.admin.cluster.node.shutdown.NodesShutdownAction;
@@ -224,7 +225,6 @@ public class ActionModule extends AbstractModule {
             actionFilterMultibinder.addBinding().to(actionFilter);
         }
         bind(ActionFilters.class).asEagerSingleton();
-
         registerAction(NodesInfoAction.INSTANCE, TransportNodesInfoAction.class);
         registerAction(NodesStatsAction.INSTANCE, TransportNodesStatsAction.class);
         registerAction(NodesShutdownAction.INSTANCE, TransportNodesShutdownAction.class);
@@ -332,10 +332,10 @@ public class ActionModule extends AbstractModule {
         for (Map.Entry<String, ActionEntry> entry : actions.entrySet()) {
             actionsBinder.addBinding(entry.getKey()).toInstance(entry.getValue().action);
         }
-
         // register GenericAction -> transportAction Map that can be injected to instances.
         // also register any supporting classes
         if (!proxy) {
+            bind(TransportLivenessAction.class).asEagerSingleton();
             MapBinder<GenericAction, TransportAction> transportActionsBinder
                     = MapBinder.newMapBinder(binder(), GenericAction.class, TransportAction.class);
             for (Map.Entry<String, ActionEntry> entry : actions.entrySet()) {

src/main/java/org/elasticsearch/action/admin/cluster/node/liveness/LivenessRequest.java

@@ -0,0 +1,33 @@
+/*
+ * 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.action.admin.cluster.node.liveness;
+
+import org.elasticsearch.action.ActionRequest;
+import org.elasticsearch.action.ActionRequestValidationException;
+
+/**
+ * Transport level private response for the transport handler registered under
+ * {@value org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction#NAME}
+ */
+public final class LivenessRequest extends ActionRequest<LivenessRequest> {
+    @Override
+    public ActionRequestValidationException validate() {
+        return null;
+    }
+}

src/main/java/org/elasticsearch/action/admin/cluster/node/liveness/LivenessResponse.java

@@ -0,0 +1,72 @@
+/*
+ * 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.action.admin.cluster.node.liveness;
+
+import org.elasticsearch.action.ActionResponse;
+import org.elasticsearch.cluster.ClusterName;
+import org.elasticsearch.cluster.node.DiscoveryNode;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+
+import java.io.IOException;
+
+/**
+ * Transport level private response for the transport handler registered under
+ * {@value org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction#NAME}
+ */
+public final class LivenessResponse extends ActionResponse {
+
+    private DiscoveryNode node;
+    private ClusterName clusterName;
+
+    public LivenessResponse() {
+    }
+
+    public LivenessResponse(ClusterName clusterName, DiscoveryNode node) {
+        this.node = node;
+        this.clusterName = clusterName;
+    }
+
+    @Override
+    public void readFrom(StreamInput in) throws IOException {
+        super.readFrom(in);
+        clusterName = ClusterName.readClusterName(in);
+        if (in.readBoolean()) {
+            node = DiscoveryNode.readNode(in);
+        } else {
+            node = null;
+        }
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        clusterName.writeTo(out);
+        out.writeOptionalStreamable(node);
+    }
+
+    public ClusterName getClusterName() {
+        return clusterName;
+    }
+
+    public DiscoveryNode getDiscoveryNode() {
+        return node;
+    }
+}

src/main/java/org/elasticsearch/action/admin/cluster/node/liveness/TransportLivenessAction.java

@@ -0,0 +1,57 @@
+/*
+ * 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.action.admin.cluster.node.liveness;
+
+import org.elasticsearch.cluster.ClusterName;
+import org.elasticsearch.cluster.ClusterService;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.*;
+
+public final class TransportLivenessAction extends BaseTransportRequestHandler<LivenessRequest> {
+
+    private final ClusterService clusterService;
+    private final ClusterName clusterName;
+    public static final String NAME = "cluster:monitor/nodes/liveness";
+
+    @Inject
+    public TransportLivenessAction(ClusterName clusterName,
+                                   ClusterService clusterService, TransportService transportService) {
+        this.clusterService = clusterService;
+        this.clusterName = clusterName;
+        transportService.registerHandler(NAME, this);
+    }
+
+    @Override
+    public LivenessRequest newInstance() {
+        return new LivenessRequest();
+    }
+
+    @Override
+    public void messageReceived(LivenessRequest request, TransportChannel channel) throws Exception {
+        channel.sendResponse(new LivenessResponse(clusterName, clusterService.localNode()));
+    }
+
+    @Override
+    public String executor() {
+        return ThreadPool.Names.SAME;
+    }
+}

src/main/java/org/elasticsearch/client/transport/TransportClientNodesService.java

@@ -28,8 +28,9 @@ import org.elasticsearch.ElasticsearchIllegalStateException;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.action.admin.cluster.node.info.NodesInfoAction;
+import org.elasticsearch.action.admin.cluster.node.liveness.LivenessRequest;
-import org.elasticsearch.action.admin.cluster.node.info.NodesInfoResponse;
+import org.elasticsearch.action.admin.cluster.node.liveness.LivenessResponse;
+import org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateAction;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
 import org.elasticsearch.client.Requests;
@@ -347,21 +348,21 @@ public class TransportClientNodesService extends AbstractComponent {
                     }
                 }
                 try {
-                    NodesInfoResponse nodeInfo = transportService.submitRequest(listedNode, NodesInfoAction.NAME,
+                    LivenessResponse livenessResponse = transportService.submitRequest(listedNode, TransportLivenessAction.NAME,
-                            headers.applyTo(Requests.nodesInfoRequest("_local").clear()),
+                            headers.applyTo(new LivenessRequest()),
                             TransportRequestOptions.options().withType(TransportRequestOptions.Type.STATE).withTimeout(pingTimeout),
-                            new FutureTransportResponseHandler<NodesInfoResponse>() {
+                            new FutureTransportResponseHandler<LivenessResponse>() {
                                 @Override
-                                public NodesInfoResponse newInstance() {
+                                public LivenessResponse newInstance() {
-                                    return new NodesInfoResponse();
+                                    return new LivenessResponse();
                                 }
                             }).txGet();
-                    if (!ignoreClusterName && !clusterName.equals(nodeInfo.getClusterName())) {
+                    if (!ignoreClusterName && !clusterName.equals(livenessResponse.getClusterName())) {
                         logger.warn("node {} not part of the cluster {}, ignoring...", listedNode, clusterName);
                         newFilteredNodes.add(listedNode);
-                    } else if (nodeInfo.getNodes().length != 0) {
+                    } else if (livenessResponse.getDiscoveryNode() != null) {
                         // use discovered information but do keep the original transport address, so people can control which address is exactly used.
-                        DiscoveryNode nodeWithInfo = nodeInfo.getNodes()[0].getNode();
+                        DiscoveryNode nodeWithInfo = livenessResponse.getDiscoveryNode();
                         newNodes.add(new DiscoveryNode(nodeWithInfo.name(), nodeWithInfo.id(), nodeWithInfo.getHostName(), nodeWithInfo.getHostAddress(), listedNode.address(), nodeWithInfo.attributes(), nodeWithInfo.version()));
                     } else {
                         // although we asked for one node, our target may not have completed initialization yet and doesn't have cluster nodes

src/main/java/org/elasticsearch/transport/TransportModule.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.transport;
 
+import org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.inject.AbstractModule;
 import org.elasticsearch.common.logging.ESLogger;

src/test/java/org/elasticsearch/client/transport/FailAndRetryMockTransport.java

@@ -25,6 +25,7 @@ import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
 import org.elasticsearch.action.admin.cluster.node.info.NodesInfoResponse;
+import org.elasticsearch.action.admin.cluster.node.liveness.LivenessResponse;
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.component.Lifecycle;
@@ -63,9 +64,7 @@ abstract class FailAndRetryMockTransport<Response extends TransportResponse> imp
         //we make sure that nodes get added to the connected ones when calling addTransportAddress, by returning proper nodes info
         if (connectMode) {
             TransportResponseHandler transportResponseHandler = transportServiceAdapter.remove(requestId);
-            NodeInfo nodeInfo = new NodeInfo(Version.CURRENT, Build.CURRENT, node, null, null, null, null, null, null, null, null, null, null);
+            transportResponseHandler.handleResponse(new LivenessResponse(ClusterName.DEFAULT, node));
-            NodesInfoResponse nodesInfoResponse = new NodesInfoResponse(ClusterName.DEFAULT, new NodeInfo[]{nodeInfo});
-            transportResponseHandler.handleResponse(nodesInfoResponse);
             return;
         }
 

src/test/java/org/elasticsearch/client/transport/TransportClientHeadersTests.java

@@ -21,9 +21,8 @@ package org.elasticsearch.client.transport;
 
 import org.elasticsearch.Version;
 import org.elasticsearch.action.GenericAction;
-import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
+import org.elasticsearch.action.admin.cluster.node.liveness.LivenessResponse;
-import org.elasticsearch.action.admin.cluster.node.info.NodesInfoAction;
+import org.elasticsearch.action.admin.cluster.node.liveness.TransportLivenessAction;
-import org.elasticsearch.action.admin.cluster.node.info.NodesInfoResponse;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateAction;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
 import org.elasticsearch.client.AbstractClientHeadersTests;
@@ -105,9 +104,9 @@ public class TransportClientHeadersTests extends AbstractClientHeadersTests {
 
         @Override @SuppressWarnings("unchecked")
         public <T extends TransportResponse> void sendRequest(DiscoveryNode node, String action, TransportRequest request, TransportRequestOptions options, TransportResponseHandler<T> handler) {
-            if (NodesInfoAction.NAME.equals(action)) {
+            if (TransportLivenessAction.NAME.equals(action)) {
                 assertHeaders(request);
-                ((TransportResponseHandler<NodesInfoResponse>) handler).handleResponse(new NodesInfoResponse(ClusterName.DEFAULT, new NodeInfo[0]));
+                ((TransportResponseHandler<LivenessResponse>) handler).handleResponse(new LivenessResponse(ClusterName.DEFAULT, node));
                 return;
             }
             if (ClusterStateAction.NAME.equals(action)) {