| /* |
| * 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.camel.component.jgroups.cluster; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Optional; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.locks.Lock; |
| |
| import org.apache.camel.CamelContext; |
| import org.apache.camel.cluster.CamelClusterMember; |
| import org.apache.camel.cluster.CamelClusterService; |
| import org.apache.camel.support.cluster.AbstractCamelClusterView; |
| import org.apache.camel.util.ObjectHelper; |
| import org.jgroups.JChannel; |
| import org.jgroups.blocks.locking.LockService; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| public class JGroupsLockClusterView extends AbstractCamelClusterView { |
| |
| private static final transient Logger LOG = LoggerFactory.getLogger(JGroupsLockClusterView.class); |
| private final CamelClusterMember localMember = new JGropusLocalMember(); |
| private String jgroupsConfig; |
| private String jgroupsClusterName; |
| private String lockName; |
| private JChannel channel; |
| private LockService lockService; |
| private Lock lock; |
| private ScheduledExecutorService executor; |
| private volatile boolean isMaster; |
| |
| protected JGroupsLockClusterView(CamelClusterService cluster, String namespace, String jgroupsConfig, String jgroupsClusterName) { |
| super(cluster, namespace); |
| lockName = namespace; |
| this.jgroupsConfig = jgroupsConfig; |
| this.jgroupsClusterName = jgroupsClusterName; |
| } |
| |
| @Override |
| public Optional<CamelClusterMember> getLeader() { |
| if (isMaster) { |
| return Optional.of(localMember); |
| } else { |
| return Optional.empty(); |
| } |
| } |
| |
| @Override |
| public CamelClusterMember getLocalMember() { |
| return localMember; |
| } |
| |
| @Override |
| public List<CamelClusterMember> getMembers() { |
| return new ArrayList<CamelClusterMember>() {{ add(localMember); }}; |
| } |
| |
| @Override |
| protected void doStart() throws Exception { |
| if (lock != null) { |
| lock.unlock(); |
| lock = null; |
| } |
| if (channel == null) { |
| channel = new JChannel(jgroupsConfig); |
| lockService = new LockService(channel); |
| } |
| channel.connect(jgroupsClusterName); |
| lock = lockService.getLock(lockName); |
| |
| // Camel context should be set at this stage. |
| final CamelContext context = ObjectHelper.notNull(getCamelContext(), "CamelContext"); |
| executor = context.getExecutorServiceManager().newSingleThreadScheduledExecutor(this, "JGroupsLockClusterView-" + getClusterService().getId() + "-" + lockName); |
| executor.execute(new Runnable() { |
| @Override |
| public void run() { |
| LOG.info("Attempting to become master acquiring the lock for group: " + lockName + " in JGroups cluster" + jgroupsClusterName + " with configuration: " + jgroupsConfig); |
| lock.lock(); |
| isMaster = true; |
| fireLeadershipChangedEvent(Optional.ofNullable(localMember)); |
| LOG.info("Became master by acquiring the lock for group: " + lockName + " in JGroups cluster" + jgroupsClusterName + " with configuration: " + jgroupsConfig); |
| } |
| }); |
| } |
| |
| @Override |
| protected void doStop() throws Exception { |
| shutdownExecutor(); |
| isMaster = false; |
| fireLeadershipChangedEvent(Optional.empty()); |
| clearLock(); |
| channel.disconnect(); |
| } |
| |
| @Override |
| protected void doShutdown() throws Exception { |
| shutdownExecutor(); |
| isMaster = false; |
| fireLeadershipChangedEvent(Optional.empty()); |
| clearLock(); |
| if (channel != null) { |
| channel.close(); |
| channel = null; |
| } |
| } |
| |
| private void clearLock() { |
| if (lock != null) { |
| lock.unlock(); |
| lock = null; |
| } |
| } |
| |
| private void shutdownExecutor() { |
| CamelContext context = getCamelContext(); |
| if (executor != null) { |
| if (context != null) { |
| context.getExecutorServiceManager().shutdown(executor); |
| } else { |
| executor.shutdown(); |
| } |
| executor = null; |
| } |
| } |
| |
| private final class JGropusLocalMember implements CamelClusterMember { |
| @Override |
| public boolean isLeader() { |
| return isMaster; |
| } |
| |
| @Override |
| public boolean isLocal() { |
| return true; |
| } |
| |
| @Override |
| public String getId() { |
| return getClusterService().getId(); |
| } |
| } |
| } |