org.elasticsearch.cluster.routing.RoutingService Maven / Gradle / Ivy
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* Licensed to ElasticSearch and Shay Banon under one
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* 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
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* specific language governing permissions and limitations
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package org.elasticsearch.cluster.routing;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.cluster.*;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.allocation.AllocationService;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.common.Priority;
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.newClusterStateBuilder;
import static org.elasticsearch.common.unit.TimeValue.timeValueSeconds;
/**
* A {@link RoutingService} listens to clusters state. When this service
* receives a {@link ClusterChangedEvent} the cluster state will be verified and
* the routing tables might be updated.
*
* Note: The {@link RoutingService} is responsible for cluster wide operations
* that include modifications to the cluster state. Such an operation can only
* be performed on the clusters master node. Unless the local node this service
* is running on is the clusters master node this service will not perform any
* actions.
*
*/
public class RoutingService extends AbstractLifecycleComponent implements ClusterStateListener {
private static final String CLUSTER_UPDATE_TASK_SOURCE = "routing-table-updater";
private final ThreadPool threadPool;
private final ClusterService clusterService;
private final AllocationService allocationService;
private final TimeValue schedule;
private volatile boolean routingTableDirty = false;
private volatile Future scheduledRoutingTableFuture;
@Inject
public RoutingService(Settings settings, ThreadPool threadPool, ClusterService clusterService, AllocationService allocationService) {
super(settings);
this.threadPool = threadPool;
this.clusterService = clusterService;
this.allocationService = allocationService;
this.schedule = componentSettings.getAsTime("schedule", timeValueSeconds(10));
clusterService.addFirst(this);
}
@Override
protected void doStart() throws ElasticSearchException {
}
@Override
protected void doStop() throws ElasticSearchException {
}
@Override
protected void doClose() throws ElasticSearchException {
if (scheduledRoutingTableFuture != null) {
scheduledRoutingTableFuture.cancel(true);
scheduledRoutingTableFuture = null;
}
clusterService.remove(this);
}
@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()) {
for (DiscoveryNode node : event.nodesDelta().addedNodes()) {
if (node.dataNode()) {
routingTableDirty = true;
break;
}
}
}
}
} 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, Priority.HIGH, new ClusterStateUpdateTask() {
@Override
public ClusterState execute(ClusterState currentState) {
RoutingAllocation.Result routingResult = allocationService.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();
}
}
}