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* 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.
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package org.elasticsearch.cluster.routing.allocation.command;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.RoutingNode;
import org.elasticsearch.cluster.routing.RoutingNodes;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.routing.ShardRoutingState;
import org.elasticsearch.cluster.routing.allocation.RerouteExplanation;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.cluster.routing.allocation.decider.Decision;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.xcontent.ObjectParser;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.IndexNotFoundException;
import org.elasticsearch.index.shard.ShardNotFoundException;
import java.io.IOException;
import java.util.List;
/**
* Allocates an unassigned replica shard to a specific node. Checks if allocation deciders allow allocation.
*/
public class AllocateReplicaAllocationCommand extends AbstractAllocateAllocationCommand {
public static final String NAME = "allocate_replica";
public static final ParseField COMMAND_NAME_FIELD = new ParseField(NAME);
private static final ObjectParser<AllocateReplicaAllocationCommand.Builder, Void> REPLICA_PARSER = createAllocateParser(NAME);
/**
* Creates a new {@link AllocateReplicaAllocationCommand}
*
* @param index index of the shard to assign
* @param shardId id of the shard to assign
* @param node node id of the node to assign the shard to
*/
public AllocateReplicaAllocationCommand(String index, int shardId, String node) {
super(index, shardId, node);
}
/**
* Read from a stream.
*/
public AllocateReplicaAllocationCommand(StreamInput in) throws IOException {
super(in);
}
@Override
public String name() {
return NAME;
}
public static AllocateReplicaAllocationCommand fromXContent(XContentParser parser) throws IOException {
return new Builder().parse(parser).build();
}
protected static class Builder extends AbstractAllocateAllocationCommand.Builder<AllocateReplicaAllocationCommand> {
@Override
public Builder parse(XContentParser parser) throws IOException {
return REPLICA_PARSER.parse(parser, this, null);
}
@Override
public AllocateReplicaAllocationCommand build() {
validate();
return new AllocateReplicaAllocationCommand(index, shard, node);
}
}
@Override
public RerouteExplanation execute(RoutingAllocation allocation, boolean explain) {
final DiscoveryNode discoNode;
try {
discoNode = allocation.nodes().resolveNode(node);
} catch (IllegalArgumentException e) {
return explainOrThrowRejectedCommand(explain, allocation, e);
}
final RoutingNodes routingNodes = allocation.routingNodes();
RoutingNode routingNode = routingNodes.node(discoNode.getId());
if (routingNode == null) {
return explainOrThrowMissingRoutingNode(allocation, explain, discoNode);
}
final ShardRouting primaryShardRouting;
try {
primaryShardRouting = allocation.routingTable().shardRoutingTable(index, shardId).primaryShard();
} catch (IndexNotFoundException | ShardNotFoundException e) {
return explainOrThrowRejectedCommand(explain, allocation, e);
}
if (primaryShardRouting.unassigned()) {
return explainOrThrowRejectedCommand(explain, allocation,
"trying to allocate a replica shard [" + index + "][" + shardId + "], while corresponding primary shard is still unassigned");
}
List<ShardRouting> replicaShardRoutings = allocation.routingTable().shardRoutingTable(index, shardId).replicaShardsWithState(ShardRoutingState.UNASSIGNED);
ShardRouting shardRouting;
if (replicaShardRoutings.isEmpty()) {
return explainOrThrowRejectedCommand(explain, allocation,
"all copies of [" + index + "][" + shardId + "] are already assigned. Use the move allocation command instead");
} else {
shardRouting = replicaShardRoutings.get(0);
}
Decision decision = allocation.deciders().canAllocate(shardRouting, routingNode, allocation);
if (decision.type() == Decision.Type.NO) {
// don't use explainOrThrowRejectedCommand to keep the original "NO" decision
if (explain) {
return new RerouteExplanation(this, decision);
}
throw new IllegalArgumentException("[" + name() + "] allocation of [" + index + "][" + shardId + "] on node " + discoNode + " is not allowed, reason: " + decision);
}
initializeUnassignedShard(allocation, routingNodes, routingNode, shardRouting);
return new RerouteExplanation(this, decision);
}
}