/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.activemq.artemis.core.server.impl;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.activemq.artemis.api.core.ActiveMQException;
import org.apache.activemq.artemis.api.core.Pair;
import org.apache.activemq.artemis.api.core.TransportConfiguration;
import org.apache.activemq.artemis.api.core.client.TopologyMember;
import org.apache.activemq.artemis.core.server.LiveNodeLocator;
import org.apache.activemq.artemis.utils.ConcurrentUtil;
import org.jboss.logging.Logger;
/**
* This implementation looks for any available live node, once tried with no success it is marked as
* tried and the next available is used.
*/
public class AnyLiveNodeLocatorForScaleDown extends LiveNodeLocator {
private static final Logger logger = Logger.getLogger(AnyLiveNodeLocatorForScaleDown.class);
private final Lock lock = new ReentrantLock();
private final Condition condition = lock.newCondition();
private final ActiveMQServerImpl server;
Map<String, Pair<TransportConfiguration, TransportConfiguration>> connectors = new TreeMap<>();
private String nodeID;
private String myNodeID;
public AnyLiveNodeLocatorForScaleDown(ActiveMQServerImpl server) {
super();
this.server = server;
this.myNodeID = server.getNodeID().toString();
}
@Override
public void locateNode() throws ActiveMQException {
locateNode(-1L);
}
@Override
public void locateNode(long timeout) throws ActiveMQException {
try {
lock.lock();
if (connectors.isEmpty()) {
try {
if (timeout != -1L) {
if (!ConcurrentUtil.await(condition, timeout)) {
throw new ActiveMQException("Timeout elapsed while waiting for cluster node");
}
} else {
while (connectors.isEmpty()) {
condition.await();
}
}
} catch (InterruptedException e) {
}
}
} finally {
lock.unlock();
}
}
@Override
public void nodeUP(TopologyMember topologyMember, boolean last) {
try {
lock.lock();
Pair<TransportConfiguration, TransportConfiguration> connector = new Pair<>(topologyMember.getLive(), topologyMember.getBackup());
if (topologyMember.getNodeId().equals(myNodeID)) {
if (logger.isTraceEnabled()) {
logger.trace(this + "::informing node about itself, nodeUUID=" +
server.getNodeID() + ", connectorPair=" + topologyMember + ", this = " + this);
}
return;
}
if (server.checkLiveIsNotColocated(topologyMember.getNodeId())) {
connectors.put(topologyMember.getNodeId(), connector);
condition.signal();
}
} finally {
lock.unlock();
}
}
@Override
public void nodeDown(long eventUID, String nodeID) {
try {
lock.lock();
connectors.remove(nodeID);
if (connectors.size() > 0) {
condition.signal();
}
} finally {
lock.unlock();
}
}
@Override
public String getNodeID() {
return nodeID;
}
@Override
public Pair<TransportConfiguration, TransportConfiguration> getLiveConfiguration() {
try {
lock.lock();
Iterator<String> iterator = connectors.keySet().iterator();
//sanity check but this should never happen
if (iterator.hasNext()) {
nodeID = iterator.next();
}
return connectors.get(nodeID);
} finally {
lock.unlock();
}
}
@Override
public void notifyRegistrationFailed(boolean alreadyReplicating) {
try {
lock.lock();
connectors.remove(nodeID);
} finally {
lock.unlock();
}
}
}