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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.discovery;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* Handles responses obtained when publishing a new cluster state from master to all non master nodes.
* Allows to await a reply from all non master nodes, up to a timeout
*/
public class BlockingClusterStatePublishResponseHandler {
private final CountDownLatch latch;
private final Set<DiscoveryNode> pendingNodes;
/**
* Creates a new BlockingClusterStatePublishResponseHandler
* @param publishingToNodes the set of nodes to which the cluster state will be published and should respond
*/
public BlockingClusterStatePublishResponseHandler(Set<DiscoveryNode> publishingToNodes) {
this.pendingNodes = ConcurrentCollections.newConcurrentSet();
this.pendingNodes.addAll(publishingToNodes);
this.latch = new CountDownLatch(pendingNodes.size());
}
/**
* Called for each response obtained from non master nodes
*
* @param node the node that replied to the publish event
*/
public void onResponse(DiscoveryNode node) {
boolean found = pendingNodes.remove(node);
assert found : "node [" + node + "] already responded or failed";
latch.countDown();
}
/**
* Called for each failure obtained from non master nodes
* @param node the node that replied to the publish event
*/
public void onFailure(DiscoveryNode node, Exception e) {
boolean found = pendingNodes.remove(node);
assert found : "node [" + node + "] already responded or failed";
latch.countDown();
}
/**
* Allows to wait for all non master nodes to reply to the publish event up to a timeout
* @param timeout the timeout
* @return true if the timeout expired or not, false otherwise
*/
public boolean awaitAllNodes(TimeValue timeout) throws InterruptedException {
boolean success = latch.await(timeout.millis(), TimeUnit.MILLISECONDS);
assert !success || pendingNodes.isEmpty() : "response count reached 0 but still waiting for some nodes";
return success;
}
/**
* returns a list of nodes which didn't respond yet
*/
public DiscoveryNode[] pendingNodes() {
// we use a zero length array, because if we try to pre allocate we may need to remove trailing
// nulls if some nodes responded in the meanwhile
return pendingNodes.toArray(new DiscoveryNode[0]);
}
}