/*
* 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.cluster.routing;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.cluster.ClusterChangedEvent;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateListener;
import org.elasticsearch.cluster.ClusterStateUpdateTask;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.cluster.routing.allocation.ShardsAllocation;
import org.elasticsearch.common.component.AbstractLifecycleComponent;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.threadpool.ThreadPool;
import java.util.concurrent.Future;
import static org.elasticsearch.cluster.ClusterState.*;
import static org.elasticsearch.common.unit.TimeValue.*;
/**
* @author kimchy (shay.banon)
*/
public class RoutingService extends AbstractLifecycleComponent<RoutingService> implements ClusterStateListener {
private static final String CLUSTER_UPDATE_TASK_SOURCE = "routing-table-updater";
private final ThreadPool threadPool;
private final ClusterService clusterService;
private final ShardsAllocation shardsAllocation;
private final TimeValue schedule;
private volatile boolean routingTableDirty = false;
private volatile Future scheduledRoutingTableFuture;
@Inject public RoutingService(Settings settings, ThreadPool threadPool, ClusterService clusterService, ShardsAllocation shardsAllocation) {
super(settings);
this.threadPool = threadPool;
this.clusterService = clusterService;
this.shardsAllocation = shardsAllocation;
this.schedule = componentSettings.getAsTime("schedule", timeValueSeconds(10));
}
@Override protected void doStart() throws ElasticSearchException {
clusterService.addPriority(this);
}
@Override protected void doStop() throws ElasticSearchException {
if (scheduledRoutingTableFuture != null) {
scheduledRoutingTableFuture.cancel(true);
scheduledRoutingTableFuture = null;
}
clusterService.remove(this);
}
@Override protected void doClose() throws ElasticSearchException {
}
@Override public void clusterChanged(ClusterChangedEvent event) {
if (event.source().equals(CLUSTER_UPDATE_TASK_SOURCE)) {
// that's us, ignore this event
return;
}
if (event.state().nodes().localNodeMaster()) {
// we are master, schedule the routing table updater
if (scheduledRoutingTableFuture == null) {
// a new master (us), make sure we reroute shards
routingTableDirty = true;
scheduledRoutingTableFuture = threadPool.scheduleWithFixedDelay(new RoutingTableUpdater(), schedule);
}
if (event.nodesRemoved()) {
// if nodes were removed, we don't want to wait for the scheduled task
// since we want to get primary election as fast as possible
routingTableDirty = true;
reroute();
// Commented out since we make sure to reroute whenever shards changes state or metadata changes state
// } else if (event.routingTableChanged()) {
// routingTableDirty = true;
// reroute();
} else {
if (event.nodesAdded()) {
routingTableDirty = true;
}
}
} else {
if (scheduledRoutingTableFuture != null) {
scheduledRoutingTableFuture.cancel(true);
scheduledRoutingTableFuture = null;
}
}
}
private void reroute() {
try {
if (!routingTableDirty) {
return;
}
if (lifecycle.stopped()) {
return;
}
clusterService.submitStateUpdateTask(CLUSTER_UPDATE_TASK_SOURCE, new ClusterStateUpdateTask() {
@Override public ClusterState execute(ClusterState currentState) {
RoutingAllocation.Result routingResult = shardsAllocation.reroute(currentState);
if (!routingResult.changed()) {
// no state changed
return currentState;
}
return newClusterStateBuilder().state(currentState).routingResult(routingResult).build();
}
});
routingTableDirty = false;
} catch (Exception e) {
logger.warn("Failed to reroute routing table", e);
}
}
private class RoutingTableUpdater implements Runnable {
@Override public void run() {
reroute();
}
}
}