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* 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.cluster.routing.allocation.decider;
import org.elasticsearch.cluster.SnapshotsInProgress;
import org.elasticsearch.cluster.routing.RoutingNode;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.common.settings.Settings;
/**
* This {@link org.elasticsearch.cluster.routing.allocation.decider.AllocationDecider} prevents shards that
* are currently been snapshotted to be moved to other nodes.
*/
public class SnapshotInProgressAllocationDecider extends AllocationDecider {
public static final String NAME = "snapshot_in_progress";
/**
* Creates a new {@link org.elasticsearch.cluster.routing.allocation.decider.SnapshotInProgressAllocationDecider} instance from
* given settings
*
* @param settings {@link org.elasticsearch.common.settings.Settings} to use
*/
public SnapshotInProgressAllocationDecider(Settings settings) {
super(settings);
}
/**
* Returns a {@link Decision} whether the given shard routing can be
* re-balanced to the given allocation. The default is
* {@link Decision#ALWAYS}.
*/
@Override
public Decision canRebalance(ShardRouting shardRouting, RoutingAllocation allocation) {
return canMove(shardRouting, allocation);
}
/**
* Returns a {@link Decision} whether the given shard routing can be
* allocated on the given node. The default is {@link Decision#ALWAYS}.
*/
@Override
public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation) {
return canMove(shardRouting, allocation);
}
private Decision canMove(ShardRouting shardRouting, RoutingAllocation allocation) {
if (shardRouting.primary()) {
// Only primary shards are snapshotted
SnapshotsInProgress snapshotsInProgress = allocation.custom(SnapshotsInProgress.TYPE);
if (snapshotsInProgress == null) {
// Snapshots are not running
return allocation.decision(Decision.YES, NAME, "no snapshots are currently running");
}
for (SnapshotsInProgress.Entry snapshot : snapshotsInProgress.entries()) {
SnapshotsInProgress.ShardSnapshotStatus shardSnapshotStatus = snapshot.shards().get(shardRouting.shardId());
if (shardSnapshotStatus != null && !shardSnapshotStatus.state().completed() && shardSnapshotStatus.nodeId() != null &&
shardSnapshotStatus.nodeId().equals(shardRouting.currentNodeId())) {
if (logger.isTraceEnabled()) {
logger.trace("Preventing snapshotted shard [{}] from being moved away from node [{}]",
shardRouting.shardId(), shardSnapshotStatus.nodeId());
}
return allocation.decision(Decision.THROTTLE, NAME,
"waiting for snapshotting of shard [%s] to complete on this node [%s]",
shardRouting.shardId(), shardSnapshotStatus.nodeId());
}
}
}
return allocation.decision(Decision.YES, NAME, "the shard is not being snapshotted");
}
}