/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.support.master;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.support.BaseAction;
import org.elasticsearch.cluster.ClusterChangedEvent;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.TimeoutClusterStateListener;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.discovery.MasterNotDiscoveredException;
import org.elasticsearch.node.NodeClosedException;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.*;
/**
* A base class for operations that needs to be performed on the master node.
*
* @author kimchy (shay.banon)
*/
public abstract class TransportMasterNodeOperationAction<Request extends MasterNodeOperationRequest, Response extends ActionResponse> extends BaseAction<Request, Response> {
protected final TransportService transportService;
protected final ClusterService clusterService;
final String transportAction;
final String executor;
protected TransportMasterNodeOperationAction(Settings settings, TransportService transportService, ClusterService clusterService, ThreadPool threadPool) {
super(settings, threadPool);
this.transportService = transportService;
this.clusterService = clusterService;
this.transportAction = transportAction();
this.executor = executor();
transportService.registerHandler(transportAction, new TransportHandler());
}
protected abstract String transportAction();
protected abstract String executor();
protected abstract Request newRequest();
protected abstract Response newResponse();
protected abstract Response masterOperation(Request request, ClusterState state) throws ElasticSearchException;
protected boolean localExecute(Request request) {
return false;
}
protected ClusterBlockException checkBlock(Request request, ClusterState state) {
return null;
}
protected void processBeforeDelegationToMaster(Request request, ClusterState state) {
}
@Override protected void doExecute(final Request request, final ActionListener<Response> listener) {
innerExecute(request, listener, false);
}
private void innerExecute(final Request request, final ActionListener<Response> listener, final boolean retrying) {
final ClusterState clusterState = clusterService.state();
final DiscoveryNodes nodes = clusterState.nodes();
if (nodes.localNodeMaster() || localExecute(request)) {
// check for block, if blocked, retry, else, execute locally
final ClusterBlockException blockException = checkBlock(request, clusterState);
if (blockException != null) {
if (!blockException.retryable()) {
listener.onFailure(blockException);
return;
}
clusterService.add(request.masterNodeTimeout(), new TimeoutClusterStateListener() {
@Override public void postAdded() {
ClusterBlockException blockException = checkBlock(request, clusterService.state());
if (blockException == null || !blockException.retryable()) {
clusterService.remove(this);
innerExecute(request, listener, false);
}
}
@Override public void onClose() {
clusterService.remove(this);
listener.onFailure(blockException);
}
@Override public void onTimeout(TimeValue timeout) {
clusterService.remove(this);
listener.onFailure(blockException);
}
@Override public void clusterChanged(ClusterChangedEvent event) {
ClusterBlockException blockException = checkBlock(request, event.state());
if (blockException == null || !blockException.retryable()) {
clusterService.remove(this);
innerExecute(request, listener, false);
}
}
});
} else {
threadPool.executor(executor).execute(new Runnable() {
@Override public void run() {
try {
Response response = masterOperation(request, clusterState);
listener.onResponse(response);
} catch (Exception e) {
listener.onFailure(e);
}
}
});
}
} else {
if (nodes.masterNode() == null) {
if (retrying) {
listener.onFailure(new MasterNotDiscoveredException());
} else {
clusterService.add(request.masterNodeTimeout(), new TimeoutClusterStateListener() {
@Override public void postAdded() {
ClusterState clusterStateV2 = clusterService.state();
if (clusterStateV2.nodes().masterNodeId() != null) {
// now we have a master, try and execute it...
clusterService.remove(this);
innerExecute(request, listener, true);
}
}
@Override public void onClose() {
clusterService.remove(this);
listener.onFailure(new NodeClosedException(nodes.localNode()));
}
@Override public void onTimeout(TimeValue timeout) {
clusterService.remove(this);
listener.onFailure(new MasterNotDiscoveredException());
}
@Override public void clusterChanged(ClusterChangedEvent event) {
if (event.nodesDelta().masterNodeChanged()) {
clusterService.remove(this);
innerExecute(request, listener, true);
}
}
});
}
return;
}
processBeforeDelegationToMaster(request, clusterState);
transportService.sendRequest(nodes.masterNode(), transportAction, request, new BaseTransportResponseHandler<Response>() {
@Override public Response newInstance() {
return newResponse();
}
@Override public void handleResponse(Response response) {
listener.onResponse(response);
}
@Override public String executor() {
return ThreadPool.Names.SAME;
}
@Override public void handleException(final TransportException exp) {
if (exp.unwrapCause() instanceof ConnectTransportException) {
// we want to retry here a bit to see if a new master is elected
clusterService.add(request.masterNodeTimeout(), new TimeoutClusterStateListener() {
@Override public void postAdded() {
ClusterState clusterStateV2 = clusterService.state();
if (!clusterState.nodes().masterNodeId().equals(clusterStateV2.nodes().masterNodeId())) {
// master changes while adding the listener, try here
clusterService.remove(this);
innerExecute(request, listener, false);
}
}
@Override public void onClose() {
clusterService.remove(this);
listener.onFailure(new NodeClosedException(nodes.localNode()));
}
@Override public void onTimeout(TimeValue timeout) {
clusterService.remove(this);
listener.onFailure(new MasterNotDiscoveredException());
}
@Override public void clusterChanged(ClusterChangedEvent event) {
if (event.nodesDelta().masterNodeChanged()) {
clusterService.remove(this);
innerExecute(request, listener, false);
}
}
});
} else {
listener.onFailure(exp);
}
}
});
}
}
private class TransportHandler extends BaseTransportRequestHandler<Request> {
@Override public Request newInstance() {
return newRequest();
}
@Override public String executor() {
return ThreadPool.Names.SAME;
}
@Override public void messageReceived(final Request request, final TransportChannel channel) throws Exception {
// we just send back a response, no need to fork a listener
request.listenerThreaded(false);
execute(request, new ActionListener<Response>() {
@Override public void onResponse(Response response) {
try {
channel.sendResponse(response);
} catch (Exception e) {
onFailure(e);
}
}
@Override public void onFailure(Throwable e) {
try {
channel.sendResponse(e);
} catch (Exception e1) {
logger.warn("Failed to send response", e1);
}
}
});
}
}
}