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            synchronized (bridges) {
094                if( bridges.containsKey(uri) ) {
095                    LOG.debug("Discovery agent generated a duplicate onServiceAdd event for: "+uri );
096                    return;
097                }
098            }
099            if (localURI.equals(uri)) {
100                LOG.debug("not connecting loopback: " + uri);
101                return;
102            }
103
104            if (connectionFilter != null && !connectionFilter.connectTo(uri)) {
105                LOG.debug("connectionFilter disallows connection to: " + uri);
106                return;
107            }
108
109            URI connectUri = uri;
110            try {
111                connectUri = URISupport.applyParameters(connectUri, parameters, DISCOVERED_OPTION_PREFIX);
112            } catch (URISyntaxException e) {
113                LOG.warn("could not apply query parameters: " + parameters + " to: " + connectUri, e);
114            }
115            LOG.info("Establishing network connection from " + localURI + " to " + connectUri);
116
117            Transport remoteTransport;
118            Transport localTransport;
119            try {
120                // Allows the transport to access the broker's ssl configuration.
121                SslContext.setCurrentSslContext(getBrokerService().getSslContext());
122                try {
123                    remoteTransport = TransportFactory.connect(connectUri);
124                } catch (Exception e) {
125                    LOG.warn("Could not connect to remote URI: " + connectUri + ": " + e.getMessage());
126                    LOG.debug("Connection failure exception: " + e, e);
127                    return;
128                }
129                try {
130                    localTransport = createLocalTransport();
131                } catch (Exception e) {
132                    ServiceSupport.dispose(remoteTransport);
133                    LOG.warn("Could not connect to local URI: " + localURI + ": " + e.getMessage());
134                    LOG.debug("Connection failure exception: " + e, e);
135                    return;
136                }
137            } finally {
138                SslContext.setCurrentSslContext(null);
139            }
140            NetworkBridge bridge = createBridge(localTransport, remoteTransport, event);
141            try {
142                bridge.start();
143                synchronized (bridges) {
144                    bridges.put(uri, bridge);
145                }
146            } catch (Exception e) {
147                ServiceSupport.dispose(localTransport);
148                ServiceSupport.dispose(remoteTransport);
149                LOG.warn("Could not start network bridge between: " + localURI + " and: " + uri + " due to: " + e);
150                LOG.debug("Start failure exception: " + e, e);
151                try {
152                    discoveryAgent.serviceFailed(event);
153                } catch (IOException e1) {
154                    LOG.debug("Discovery agent failure while handling failure event: " + e1.getMessage(), e1);
155                }
156            }
157        }
158    }
159
160    public void onServiceRemove(DiscoveryEvent event) {
161        String url = event.getServiceName();
162        if (url != null) {
163            URI uri;
164            try {
165                uri = new URI(url);
166            } catch (URISyntaxException e) {
167                LOG.warn("Could not connect to remote URI: " + url + " due to bad URI syntax: " + e, e);
168                return;
169            }
170
171            NetworkBridge bridge;
172            synchronized (bridges) {
173                bridge = bridges.remove(uri);
174            }
175        }
176    }
177
178    public DiscoveryAgent getDiscoveryAgent() {
179        return discoveryAgent;
180    }
181
182    public void setDiscoveryAgent(DiscoveryAgent discoveryAgent) {
183        this.discoveryAgent = discoveryAgent;
184        if (discoveryAgent != null) {
185            this.discoveryAgent.setDiscoveryListener(this);
186        }
187    }
188
189    protected void handleStart() throws Exception {
190        if (discoveryAgent == null) {
191            throw new IllegalStateException("You must configure the 'discoveryAgent' property");
192        }
193        this.discoveryAgent.start();
194        super.handleStart();
195    }
196
197    protected void handleStop(ServiceStopper stopper) throws Exception {
198        for (Iterator<NetworkBridge> i = bridges.values().iterator(); i.hasNext();) {
199            NetworkBridge bridge = i.next();
200            try {
201                bridge.stop();
202            } catch (Exception e) {
203                stopper.onException(this, e);
204            }
205        }
206        bridges.clear();
207        try {
208            this.discoveryAgent.stop();
209        } catch (Exception e) {
210            stopper.onException(this, e);
211        }
212
213        super.handleStop(stopper);
214    }
215
216    protected NetworkBridge createBridge(Transport localTransport, Transport remoteTransport, final DiscoveryEvent event) {
217        class DiscoverNetworkBridgeListener extends MBeanNetworkListener {
218
219            public DiscoverNetworkBridgeListener(BrokerService brokerService, ObjectName connectorName) {
220                super(brokerService, connectorName);
221            }
222
223            public void bridgeFailed() {
224                if (!serviceSupport.isStopped()) {
225                    try {
226                        discoveryAgent.serviceFailed(event);
227                    } catch (IOException e) {
228                    }
229                }
230
231            }
232        }
233        NetworkBridgeListener listener = new DiscoverNetworkBridgeListener(getBrokerService(), getObjectName());
234
235        DemandForwardingBridge result = NetworkBridgeFactory.createBridge(this, localTransport, remoteTransport, listener);
236        result.setBrokerService(getBrokerService());
237        return configureBridge(result);
238    }
239
240    @Override
241    public String toString() {
242        return "DiscoveryNetworkConnector:" + getName() + ":" + getBrokerService();
243    }
244}