001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.broker.cluster;
018
019import java.util.ArrayList;
020import java.util.List;
021
022import org.apache.activemq.broker.Broker;
023import org.apache.activemq.broker.BrokerFilter;
024import org.apache.activemq.broker.ConnectionContext;
025import org.apache.activemq.broker.region.Subscription;
026import org.apache.activemq.command.ActiveMQDestination;
027import org.apache.activemq.command.ConsumerId;
028import org.apache.activemq.command.ConsumerInfo;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * Monitors for client connections that may fail to another broker - but this
034 * broker isn't aware they've gone. Can occur with network glitches or client
035 * error
036 * 
037 * 
038 */
039public class ConnectionSplitBroker extends BrokerFilter{
040    private static final Logger LOG = LoggerFactory.getLogger(ConnectionSplitBroker.class);
041    private List<ConsumerInfo>networkConsumerList = new ArrayList<ConsumerInfo>();
042    public ConnectionSplitBroker(Broker next) {
043        super(next);
044    }
045
046        
047    public Subscription addConsumer(ConnectionContext context, ConsumerInfo info)
048            throws Exception {
049        ActiveMQDestination dest = info.getDestination();
050
051        synchronized (networkConsumerList) {
052            if (info.isNetworkSubscription()) {
053                networkConsumerList.add(info);
054            } else {
055                if (!networkConsumerList.isEmpty()) {
056                    List<ConsumerInfo> gcList = new ArrayList<ConsumerInfo>();
057                    for (ConsumerInfo nc : networkConsumerList) {
058                        if (!nc.isNetworkConsumersEmpty()) {
059                            
060                            for (ConsumerId id : nc.getNetworkConsumerIds()) {
061                                
062                                if (id.equals(info.getConsumerId())) {
063                                    nc.removeNetworkConsumerId(id);
064                                    if (nc.isNetworkConsumersEmpty()) {
065                                        gcList.add(nc);
066                                    }
067                                }
068                            }
069                        }
070                    }
071                    for (ConsumerInfo nc : gcList) {
072                        networkConsumerList.remove(nc);
073                        super.removeConsumer(context, nc);
074                        LOG.warn("Removed stale network consumer {}", nc);
075                    }
076                }
077            }
078        }
079
080        return super.addConsumer(context, info);
081    }
082
083    public void removeConsumer(ConnectionContext context, ConsumerInfo info) throws Exception {
084        if (info.isNetworkSubscription()) {
085
086            synchronized (networkConsumerList) {
087                networkConsumerList.remove(info);
088            }
089        }
090        super.removeConsumer(context, info);
091    }
092}