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.network;
018
019import java.io.IOException;
020import java.net.URI;
021import java.net.URISyntaxException;
022import java.util.HashMap;
023import java.util.Iterator;
024import java.util.Map;
025
026import org.apache.activemq.broker.BrokerService;
027import org.apache.activemq.broker.SslContext;
028import org.apache.activemq.command.DiscoveryEvent;
029import org.apache.activemq.transport.Transport;
030import org.apache.activemq.transport.TransportDisposedIOException;
031import org.apache.activemq.transport.TransportFactory;
032import org.apache.activemq.transport.discovery.DiscoveryAgent;
033import org.apache.activemq.transport.discovery.DiscoveryAgentFactory;
034import org.apache.activemq.transport.discovery.DiscoveryListener;
035import org.apache.activemq.util.IntrospectionSupport;
036import org.apache.activemq.util.ServiceStopper;
037import org.apache.activemq.util.ServiceSupport;
038import org.apache.activemq.util.URISupport;
039import org.apache.activemq.util.URISupport.CompositeData;
040import org.slf4j.Logger;
041import org.slf4j.LoggerFactory;
042
043import javax.management.ObjectName;
044
045/**
046 * A network connector which uses a discovery agent to detect the remote brokers
047 * available and setup a connection to each available remote broker
048 * 
049 * @org.apache.xbean.XBean element="networkConnector"
050 * 
051 */
052public class DiscoveryNetworkConnector extends NetworkConnector implements DiscoveryListener {
053    private static final Logger LOG = LoggerFactory.getLogger(DiscoveryNetworkConnector.class);
054
055    private DiscoveryAgent discoveryAgent;
056    
057    private Map<String, String> parameters;
058    
059    public DiscoveryNetworkConnector() {
060    }
061
062    public DiscoveryNetworkConnector(URI discoveryURI) throws IOException {
063        setUri(discoveryURI);
064    }
065
066    public void setUri(URI discoveryURI) throws IOException {
067        setDiscoveryAgent(DiscoveryAgentFactory.createDiscoveryAgent(discoveryURI));
068        try {
069            parameters = URISupport.parseParameters(discoveryURI);
070            // allow discovery agent to grab it's parameters
071            IntrospectionSupport.setProperties(getDiscoveryAgent(), parameters);
072        } catch (URISyntaxException e) {
073            LOG.warn("failed to parse query parameters from discoveryURI: " + discoveryURI, e);
074        }  
075        
076    }
077
078    public void onServiceAdd(DiscoveryEvent event) {
079        // Ignore events once we start stopping.
080        if (serviceSupport.isStopped() || serviceSupport.isStopping()) {
081            return;
082        }
083        String url = event.getServiceName();
084        if (url != null) {
085            URI uri;
086            try {
087                uri = new URI(url);
088            } catch (URISyntaxException e) {
089                LOG.warn("Could not connect to remote URI: " + url + " due to bad URI syntax: " + e, e);
090                return;
091            }
092            // Should we try to connect to that URI?
093            if( bridges.containsKey(uri) ) {
094                LOG.debug("Discovery agent generated a duplicate onServiceAdd event for: "+uri );
095                return;
096            }
097            if ( localURI.equals(uri) || (connectionFilter != null && !connectionFilter.connectTo(uri))) {
098                LOG.debug("not connecting loopback: " + uri);
099                return;
100            }
101            URI connectUri = uri;
102            try {
103                connectUri = URISupport.applyParameters(connectUri, parameters, DISCOVERED_OPTION_PREFIX);
104            } catch (URISyntaxException e) {
105                LOG.warn("could not apply query parameters: " + parameters + " to: " + connectUri, e);
106            }
107            LOG.info("Establishing network connection from " + localURI + " to " + connectUri);
108
109            Transport remoteTransport;
110            Transport localTransport;
111            try {
112                // Allows the transport to access the broker's ssl configuration.
113                SslContext.setCurrentSslContext(getBrokerService().getSslContext());
114                try {
115                    remoteTransport = TransportFactory.connect(connectUri);
116                } catch (Exception e) {
117                    LOG.warn("Could not connect to remote URI: " + connectUri + ": " + e.getMessage());
118                    LOG.debug("Connection failure exception: " + e, e);
119                    return;
120                }
121                try {
122                    localTransport = createLocalTransport();
123                } catch (Exception e) {
124                    ServiceSupport.dispose(remoteTransport);
125                    LOG.warn("Could not connect to local URI: " + localURI + ": " + e.getMessage());
126                    LOG.debug("Connection failure exception: " + e, e);
127                    return;
128                }
129            } finally {
130                SslContext.setCurrentSslContext(null);
131            }
132            NetworkBridge bridge = createBridge(localTransport, remoteTransport, event);
133            try {
134                bridge.start();
135                bridges.put(uri, bridge);
136            } catch (TransportDisposedIOException e) {
137                LOG.warn("Network bridge between: " + localURI + " and: " + uri + " was correctly stopped before it was correctly started.");
138            } catch (Exception e) {
139                ServiceSupport.dispose(localTransport);
140                ServiceSupport.dispose(remoteTransport);
141                LOG.warn("Could not start network bridge between: " + localURI + " and: " + uri + " due to: " + e);
142                LOG.debug("Start failure exception: " + e, e);
143                try {
144                    discoveryAgent.serviceFailed(event);
145                } catch (IOException e1) {
146                    LOG.debug("Discovery agent failure while handling failure event: " + e1.getMessage(), e1);
147                }
148                return;
149            }
150        }
151    }
152
153    public void onServiceRemove(DiscoveryEvent event) {
154        String url = event.getServiceName();
155        if (url != null) {
156            URI uri;
157            try {
158                uri = new URI(url);
159            } catch (URISyntaxException e) {
160                LOG.warn("Could not connect to remote URI: " + url + " due to bad URI syntax: " + e, e);
161                return;
162            }
163
164            NetworkBridge bridge = bridges.remove(uri);
165            if (bridge == null) {
166                return;
167            }
168
169            ServiceSupport.dispose(bridge);
170        }
171    }
172
173    public DiscoveryAgent getDiscoveryAgent() {
174        return discoveryAgent;
175    }
176
177    public void setDiscoveryAgent(DiscoveryAgent discoveryAgent) {
178        this.discoveryAgent = discoveryAgent;
179        if (discoveryAgent != null) {
180            this.discoveryAgent.setDiscoveryListener(this);
181        }
182    }
183
184    protected void handleStart() throws Exception {
185        if (discoveryAgent == null) {
186            throw new IllegalStateException("You must configure the 'discoveryAgent' property");
187        }
188        this.discoveryAgent.start();
189        super.handleStart();
190    }
191
192    protected void handleStop(ServiceStopper stopper) throws Exception {
193        for (Iterator<NetworkBridge> i = bridges.values().iterator(); i.hasNext();) {
194            NetworkBridge bridge = i.next();
195            try {
196                bridge.stop();
197            } catch (Exception e) {
198                stopper.onException(this, e);
199            }
200        }
201        try {
202            this.discoveryAgent.stop();
203        } catch (Exception e) {
204            stopper.onException(this, e);
205        }
206
207        super.handleStop(stopper);
208    }
209
210    protected NetworkBridge createBridge(Transport localTransport, Transport remoteTransport, final DiscoveryEvent event) {
211        class DiscoverNetworkBridgeListener extends MBeanNetworkListener {
212
213            public DiscoverNetworkBridgeListener(BrokerService brokerService, ObjectName connectorName) {
214                super(brokerService, connectorName);
215            }
216
217            public void bridgeFailed() {
218                if (!serviceSupport.isStopped()) {
219                    try {
220                        discoveryAgent.serviceFailed(event);
221                    } catch (IOException e) {
222                    }
223                }
224
225            }
226        }
227        NetworkBridgeListener listener = new DiscoverNetworkBridgeListener(getBrokerService(), getObjectName());
228
229        DemandForwardingBridge result = NetworkBridgeFactory.createBridge(this, localTransport, remoteTransport, listener);
230        result.setBrokerService(getBrokerService());
231        return configureBridge(result);
232    }
233
234    @Override
235    public String toString() {
236        return "DiscoveryNetworkConnector:" + getName() + ":" + getBrokerService();
237    }
238}