opendaylight/clustering/services_implementation/src/main/java/org/opendaylight/controller/clustering/services_implementation/internal/ClusterManager.java

   1
   2 /*
   3  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   4  *
   5  * This program and the accompanying materials are made available under the
   6  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   7  * and is available at http://www.eclipse.org/legal/epl-v10.html
   8  */
   9
  10 package org.opendaylight.controller.clustering.services_implementation.internal;
  11
  12 import java.net.InetAddress;
  13 import java.net.NetworkInterface;
  14 import java.net.SocketException;
  15 import java.net.UnknownHostException;
  16 import java.util.ArrayList;
  17 import java.util.EnumSet;
  18 import java.util.Enumeration;
  19 import java.util.HashSet;
  20 import java.util.List;
  21 import java.util.Properties;
  22 import java.util.Set;
  23 import java.util.StringTokenizer;
  24 import java.util.concurrent.ConcurrentMap;
  25
  26 import javax.transaction.HeuristicMixedException;
  27 import javax.transaction.HeuristicRollbackException;
  28 import javax.transaction.NotSupportedException;
  29 import javax.transaction.RollbackException;
  30 import javax.transaction.SystemException;
  31 import javax.transaction.Transaction;
  32 import javax.transaction.TransactionManager;
  33
  34 import org.infinispan.Cache;
  35 import org.infinispan.configuration.cache.Configuration;
  36 import org.infinispan.configuration.cache.ConfigurationBuilder;
  37 import org.infinispan.configuration.global.GlobalConfigurationBuilder;
  38 import org.infinispan.configuration.parsing.ConfigurationBuilderHolder;
  39 import org.infinispan.configuration.parsing.ParserRegistry;
  40 import org.infinispan.manager.DefaultCacheManager;
  41 import org.infinispan.manager.EmbeddedCacheManager;
  42 import org.infinispan.notifications.Listener;
  43 import org.infinispan.notifications.cachemanagerlistener.annotation.ViewChanged;
  44 import org.infinispan.notifications.cachemanagerlistener.event.ViewChangedEvent;
  45 import org.infinispan.remoting.transport.Address;
  46 import org.infinispan.remoting.transport.Transport;
  47 import org.infinispan.remoting.transport.jgroups.JGroupsAddress;
  48 import org.infinispan.remoting.transport.jgroups.JGroupsTransport;
  49 import org.jgroups.Channel;
  50 import org.jgroups.Event;
  51 import org.jgroups.stack.GossipRouter;
  52 import org.opendaylight.controller.clustering.services.CacheConfigException;
  53 import org.opendaylight.controller.clustering.services.CacheExistException;
  54 import org.opendaylight.controller.clustering.services.CacheListenerAddException;
  55 import org.opendaylight.controller.clustering.services.IClusterServices;
  56 import org.opendaylight.controller.clustering.services.IGetUpdates;
  57 import org.opendaylight.controller.clustering.services.IListenRoleChange;
  58 import org.opendaylight.controller.clustering.services.ListenRoleChangeAddException;
  59 import org.slf4j.Logger;
  60 import org.slf4j.LoggerFactory;
  61
  62 public class ClusterManager implements IClusterServices {
  63     protected static final Logger logger = LoggerFactory
  64             .getLogger(ClusterManager.class);
  65     private DefaultCacheManager cm;
  66     GossipRouter gossiper;
  67     private HashSet<IListenRoleChange> roleChangeListeners;
  68     private ViewChangedListener cacheManagerListener;
  69
  70     private static String loopbackAddress = "127.0.0.1";
  71
  72     /**
  73      * Start a JGroups GossipRouter if we are a supernode. The
  74      * GosispRouter is nothing more than a simple
  75      * rendevouz-pointer. All the nodes that wants to join the cluster
  76      * will come to any of the rendevouz point and they introduce the
  77      * nodes to all the others. Once the meet and greet phase if over,
  78      * the nodes will open a full-mesh with the remaining n-1 nodes,
  79      * so even if the GossipRouter goes down nothing is lost.
  80      * NOTE: This function has the side effect to set some of the
  81      * JGROUPS configurations, this because in this function already
  82      * we try to retrieve some of the network capabilities of the
  83      * device and so it's better not to do that again
  84      *
  85      *
  86      * @return GossipRouter
  87      */
  88     private GossipRouter startGossiper() {
  89         boolean amIGossipRouter = false;
  90         Integer gossipRouterPortDefault = 12001;
  91         Integer gossipRouterPort = gossipRouterPortDefault;
  92         InetAddress gossipRouterAddress = null;
  93         String supernodes_list = System.getProperty("supernodes",
  94                 loopbackAddress);
  95         StringBuffer sanitized_supernodes_list = new StringBuffer();
  96         List<InetAddress> myAddresses = new ArrayList<InetAddress>();
  97
  98         StringTokenizer supernodes = new StringTokenizer(supernodes_list, ":");
  99         if (supernodes.hasMoreTokens()) {
 100             // Populate the list of my addresses
 101             try {
 102                 Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces();
 103                 while (e.hasMoreElements()) {
 104                     NetworkInterface n = e.nextElement();
 105                     Enumeration<InetAddress> ee = n.getInetAddresses();
 106                     while (ee.hasMoreElements()) {
 107                         InetAddress i = ee.nextElement();
 108                         myAddresses.add(i);
 109                     }
 110                 }
 111             } catch (SocketException se) {
 112                 logger.error("Cannot get the list of network interfaces");
 113                 return null;
 114             }
 115         }
 116         while (supernodes.hasMoreTokens()) {
 117             String curr_supernode = supernodes.nextToken();
 118             logger.debug("Examining supernode {}", curr_supernode);
 119             StringTokenizer host_port = new StringTokenizer(curr_supernode,
 120                     "[]");
 121             String host;
 122             String port;
 123             Integer port_num = gossipRouterPortDefault;
 124             if (host_port.countTokens() > 2) {
 125                 logger.error("Error parsing supernode {} proceed to the next one",
 126                         curr_supernode);
 127                 continue;
 128             }
 129             host = host_port.nextToken();
 130             InetAddress hostAddr;
 131             try {
 132                 hostAddr = InetAddress.getByName(host);
 133             } catch (UnknownHostException ue) {
 134                 logger.error("Host not known");
 135                 continue;
 136             }
 137             if (host_port.hasMoreTokens()) {
 138                 port = host_port.nextToken();
 139                 try {
 140                     port_num = Integer.valueOf(port);
 141                 } catch (NumberFormatException ne) {
 142                     logger
 143                             .error("Supplied supernode gossiepr port is not recognized, using standard gossipport");
 144                     port_num = gossipRouterPortDefault;
 145                 }
 146                 if ((port_num > 65535) || (port_num < 0)) {
 147                     logger
 148                             .error("Supplied supernode gossip port is outside a valid TCP port range");
 149                     port_num = gossipRouterPortDefault;
 150                 }
 151             }
 152             if (!amIGossipRouter) {
 153                 if (host != null) {
 154                     for (InetAddress myAddr : myAddresses) {
 155                         if (myAddr.equals(hostAddr)) {
 156                             amIGossipRouter = true;
 157                             gossipRouterAddress = hostAddr;
 158                             gossipRouterPort = port_num;
 159                             break;
 160                         }
 161                     }
 162                 }
 163             }
 164             if (!sanitized_supernodes_list.toString().equals("")) {
 165                 sanitized_supernodes_list.append(",");
 166             }
 167             sanitized_supernodes_list.append(hostAddr.getHostAddress() + "["
 168                     + port_num + "]");
 169         }
 170
 171         if (amIGossipRouter) {
 172             // Set the Jgroups binding interface to the one we got
 173             // from the supernodes attribute
 174             if (gossipRouterAddress != null) {
 175                 System.setProperty("jgroups.tcp.address", gossipRouterAddress
 176                         .getHostAddress());
 177             }
 178         } else {
 179             // Set the Jgroup binding interface to the one we are well
 180             // known outside or else to the first with non-local
 181             // scope.
 182             try {
 183                 String myBind = InetAddress.getLocalHost().getHostAddress();
 184                 if (myBind == null
 185                         || InetAddress.getLocalHost().isLoopbackAddress()) {
 186                     for (InetAddress myAddr : myAddresses) {
 187                         if (myAddr.isLoopbackAddress()
 188                                 || myAddr.isLinkLocalAddress()) {
 189                             logger.debug("Skipping local address {}",
 190                                          myAddr.getHostAddress());
 191                             continue;
 192                         } else {
 193                             // First non-local address
 194                             myBind = myAddr.getHostAddress();
 195                             logger.debug("First non-local address {}", myBind);
 196                             break;
 197                         }
 198                     }
 199                 }
 200                 String jgroupAddress = System
 201                         .getProperty("jgroups.tcp.address");
 202                 if (jgroupAddress == null) {
 203                     if (myBind != null) {
 204                         logger.debug("Set bind address to be {}", myBind);
 205                         System.setProperty("jgroups.tcp.address", myBind);
 206                     } else {
 207                         logger
 208                                 .debug("Set bind address to be LOCALHOST=127.0.0.1");
 209                         System.setProperty("jgroups.tcp.address", "127.0.0.1");
 210                     }
 211                 } else {
 212                     logger.debug("jgroup.tcp.address already set to be {}",
 213                             jgroupAddress);
 214                 }
 215             } catch (UnknownHostException uhe) {
 216                 logger
 217                         .error("Met UnknownHostException while trying to get binding address for jgroups");
 218             }
 219         }
 220
 221         // The supernodes list constitute also the tcpgossip initial
 222         // host list
 223         System.setProperty("jgroups.tcpgossip.initial_hosts",
 224                 sanitized_supernodes_list.toString());
 225         logger.debug("jgroups.tcp.address set to {}",
 226                 System.getProperty("jgroups.tcp.address"));
 227         logger.debug("jgroups.tcpgossip.initial_hosts set to {}",
 228                 System.getProperty("jgroups.tcpgossip.initial_hosts"));
 229         GossipRouter res = null;
 230         if (amIGossipRouter) {
 231             logger.info("I'm a GossipRouter will listen on port {}",
 232                     gossipRouterPort);
 233             // Start a GossipRouter with JMX support
 234             res = new GossipRouter(gossipRouterPort, null, true);
 235         }
 236         return res;
 237     }
 238
 239     public void start() {
 240         this.gossiper = startGossiper();
 241         if (this.gossiper != null) {
 242             logger.debug("Trying to start Gossiper");
 243             try {
 244                 this.gossiper.start();
 245                 logger.info("Started GossipRouter");
 246             } catch (Exception e) {
 247                 logger.error("GossipRouter didn't start. Exception Stack Trace",
 248                              e);
 249             }
 250         }
 251         logger.info("Starting the ClusterManager");
 252         try {
 253             ParserRegistry parser = new ParserRegistry(this.getClass()
 254                     .getClassLoader());
 255             String infinispanConfigFile =
 256                     System.getProperty("org.infinispan.config.file", "config/infinispan-config.xml");
 257             logger.debug("Using configuration file:{}", infinispanConfigFile);
 258             ConfigurationBuilderHolder holder = parser.parseFile(infinispanConfigFile);
 259             GlobalConfigurationBuilder globalBuilder = holder.getGlobalConfigurationBuilder();
 260             globalBuilder.serialization()
 261                     .classResolver(new ClassResolver())
 262                     .build();
 263             this.cm = new DefaultCacheManager(holder, false);
 264             logger.debug("Allocated ClusterManager");
 265             if (this.cm != null) {
 266                 this.cm.start();
 267                 this.cm.startCache();
 268                 logger.debug("Started the ClusterManager");
 269             }
 270         } catch (Exception ioe) {
 271             logger.error("Cannot configure infinispan .. bailing out ");
 272             logger.error("Stack Trace that raised th exception");
 273             logger.error("",ioe);
 274             this.cm = null;
 275             this.stop();
 276         }
 277         logger.debug("Cache Manager has value {}", this.cm);
 278     }
 279
 280     public void stop() {
 281         logger.info("Stopping the ClusterManager");
 282         if (this.cm != null) {
 283             logger.info("Found a valid ClusterManager, now let it be stopped");
 284             this.cm.stop();
 285             this.cm = null;
 286         }
 287         if (this.gossiper != null) {
 288             this.gossiper.stop();
 289             this.gossiper = null;
 290         }
 291     }
 292
 293     @Override
 294     public ConcurrentMap<?, ?> createCache(String containerName,
 295             String cacheName, Set<cacheMode> cMode) throws CacheExistException,
 296             CacheConfigException {
 297         EmbeddedCacheManager manager = this.cm;
 298         Cache<Object,Object> c;
 299         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 300         if (manager == null) {
 301             return null;
 302         }
 303
 304         if (manager.cacheExists(realCacheName)) {
 305             throw new CacheExistException();
 306         }
 307
 308         // Sanity check to avoid contrasting parameters between transactional
 309         // and not
 310         if (cMode.containsAll(EnumSet.of(IClusterServices.cacheMode.NON_TRANSACTIONAL,
 311                 IClusterServices.cacheMode.TRANSACTIONAL))) {
 312             throw new CacheConfigException();
 313         }
 314
 315         // Sanity check to avoid contrasting parameters between sync and async
 316         if (cMode.containsAll(EnumSet.of(IClusterServices.cacheMode.SYNC, IClusterServices.cacheMode.ASYNC))) {
 317             throw new CacheConfigException();
 318         }
 319
 320         Configuration fromTemplateConfig = null;
 321         /*
 322          * Fetch transactional/non-transactional templates
 323          */
 324         // Check if transactional
 325         if (cMode.contains(IClusterServices.cacheMode.TRANSACTIONAL)) {
 326             fromTemplateConfig = manager.getCacheConfiguration("transactional-type");
 327         } else if (cMode.contains(IClusterServices.cacheMode.NON_TRANSACTIONAL)) {
 328             fromTemplateConfig = manager.getDefaultCacheConfiguration();
 329         }
 330
 331         // If none set the transactional property then just return null
 332         if (fromTemplateConfig == null) {
 333             return null;
 334         }
 335
 336         ConfigurationBuilder builder = new ConfigurationBuilder();
 337         builder.read(fromTemplateConfig);
 338         /*
 339          * Now evaluate async/sync
 340          */
 341         if (cMode.contains(IClusterServices.cacheMode.ASYNC)) {
 342             builder.clustering()
 343                     .cacheMode(fromTemplateConfig.clustering()
 344                             .cacheMode()
 345                             .toAsync());
 346         } else if (cMode.contains(IClusterServices.cacheMode.SYNC)) {
 347             builder.clustering()
 348                     .cacheMode(fromTemplateConfig.clustering()
 349                             .cacheMode()
 350                             .toSync());
 351         }
 352
 353         manager.defineConfiguration(realCacheName, builder.build());
 354         c = manager.getCache(realCacheName);
 355         return c;
 356     }
 357
 358     @Override
 359     public ConcurrentMap<?, ?> getCache(String containerName, String cacheName) {
 360         EmbeddedCacheManager manager = this.cm;
 361         Cache<Object,Object> c;
 362         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 363         if (manager == null) {
 364             return null;
 365         }
 366
 367         if (manager.cacheExists(realCacheName)) {
 368             c = manager.getCache(realCacheName);
 369             return c;
 370         }
 371         return null;
 372     }
 373
 374     @Override
 375     public void destroyCache(String containerName, String cacheName) {
 376         EmbeddedCacheManager manager = this.cm;
 377         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 378         if (manager == null) {
 379             return;
 380         }
 381         if (manager.cacheExists(realCacheName)) {
 382             manager.removeCache(realCacheName);
 383         }
 384     }
 385
 386     @Override
 387     public boolean existCache(String containerName, String cacheName) {
 388         EmbeddedCacheManager manager = this.cm;
 389         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 390         if (manager == null) {
 391             return false;
 392         }
 393         return manager.cacheExists(realCacheName);
 394     }
 395
 396     @Override
 397     public Set<String> getCacheList(String containerName) {
 398         Set<String> perContainerCaches = new HashSet<String>();
 399         EmbeddedCacheManager manager = this.cm;
 400         if (manager == null) {
 401             return null;
 402         }
 403         for (String cacheName : manager.getCacheNames()) {
 404             if (!manager.isRunning(cacheName)) continue;
 405             if (cacheName.startsWith("{" + containerName + "}_")) {
 406                 String[] res = cacheName.split("[{}]");
 407                 if (res.length >= 4 && res[1].equals(containerName)
 408                         && res[2].equals("_")) {
 409                     perContainerCaches.add(res[3]);
 410                 }
 411             }
 412         }
 413
 414         return (perContainerCaches);
 415     }
 416
 417     @Override
 418     public Properties getCacheProperties(String containerName, String cacheName) {
 419         EmbeddedCacheManager manager = this.cm;
 420         if (manager == null) {
 421             return null;
 422         }
 423         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 424         if (!manager.cacheExists(realCacheName)) {
 425             return null;
 426         }
 427         Configuration conf = manager.getCache(realCacheName).getAdvancedCache()
 428                 .getCacheConfiguration();
 429         Properties p = new Properties();
 430         p.setProperty(IClusterServices.cacheProps.TRANSACTION_PROP.toString(),
 431                 conf.transaction().toString());
 432         p.setProperty(IClusterServices.cacheProps.CLUSTERING_PROP.toString(),
 433                 conf.clustering().toString());
 434         p.setProperty(IClusterServices.cacheProps.LOCKING_PROP.toString(), conf
 435                 .locking().toString());
 436         return p;
 437     }
 438
 439     @Override
 440     public void addListener(String containerName, String cacheName,
 441             IGetUpdates<?, ?> u) throws CacheListenerAddException {
 442         EmbeddedCacheManager manager = this.cm;
 443         Cache<Object,Object> c;
 444         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 445         if (manager == null) {
 446             return;
 447         }
 448
 449         if (!manager.cacheExists(realCacheName)) {
 450             throw new CacheListenerAddException();
 451         }
 452         c = manager.getCache(realCacheName);
 453         CacheListenerContainer cl = new CacheListenerContainer(u,
 454                 containerName, cacheName);
 455         c.addListener(cl);
 456     }
 457
 458     @Override
 459     public Set<IGetUpdates<?, ?>> getListeners(String containerName,
 460             String cacheName) {
 461         EmbeddedCacheManager manager = this.cm;
 462         Cache<Object,Object> c;
 463         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 464         if (manager == null) {
 465             return null;
 466         }
 467
 468         if (!manager.cacheExists(realCacheName)) {
 469             return null;
 470         }
 471         c = manager.getCache(realCacheName);
 472
 473         Set<IGetUpdates<?, ?>> res = new HashSet<IGetUpdates<?, ?>>();
 474         Set<Object> listeners = c.getListeners();
 475         for (Object listener : listeners) {
 476             if (listener instanceof CacheListenerContainer) {
 477                 CacheListenerContainer cl = (CacheListenerContainer) listener;
 478                 res.add(cl.whichListener());
 479             }
 480         }
 481
 482         return res;
 483     }
 484
 485     @Override
 486     public void removeListener(String containerName, String cacheName,
 487             IGetUpdates<?, ?> u) {
 488         EmbeddedCacheManager manager = this.cm;
 489         Cache<Object,Object> c;
 490         String realCacheName = "{" + containerName + "}_{" + cacheName + "}";
 491         if (manager == null) {
 492             return;
 493         }
 494
 495         if (!manager.cacheExists(realCacheName)) {
 496             return;
 497         }
 498         c = manager.getCache(realCacheName);
 499
 500         Set<Object> listeners = c.getListeners();
 501         for (Object listener : listeners) {
 502             if (listener instanceof CacheListenerContainer) {
 503                 CacheListenerContainer cl = (CacheListenerContainer) listener;
 504                 if (cl.whichListener() == u) {
 505                     c.removeListener(listener);
 506                     return;
 507                 }
 508             }
 509         }
 510     }
 511
 512     @Override
 513     public void tbegin() throws NotSupportedException, SystemException {
 514         EmbeddedCacheManager manager = this.cm;
 515         if (manager == null) {
 516             throw new IllegalStateException();
 517         }
 518         TransactionManager tm = manager.getCache("transactional-type")
 519                 .getAdvancedCache().getTransactionManager();
 520         if (tm == null) {
 521             throw new IllegalStateException();
 522         }
 523         tm.begin();
 524     }
 525
 526     @Override
 527     public void tcommit() throws RollbackException, HeuristicMixedException,
 528             HeuristicRollbackException, java.lang.SecurityException,
 529             java.lang.IllegalStateException, SystemException {
 530         EmbeddedCacheManager manager = this.cm;
 531         if (manager == null) {
 532             throw new IllegalStateException();
 533         }
 534         TransactionManager tm = manager.getCache("transactional-type")
 535                 .getAdvancedCache().getTransactionManager();
 536         if (tm == null) {
 537             throw new IllegalStateException();
 538         }
 539         tm.commit();
 540     }
 541
 542     @Override
 543     public void trollback() throws java.lang.IllegalStateException,
 544             java.lang.SecurityException, SystemException {
 545         EmbeddedCacheManager manager = this.cm;
 546         if (manager == null) {
 547             throw new IllegalStateException();
 548         }
 549         TransactionManager tm = manager.getCache("transactional-type")
 550                 .getAdvancedCache().getTransactionManager();
 551         if (tm == null) {
 552             throw new IllegalStateException();
 553         }
 554         tm.rollback();
 555     }
 556
 557     @Override
 558     public Transaction tgetTransaction() throws SystemException {
 559         EmbeddedCacheManager manager = this.cm;
 560         if (manager == null) {
 561             throw new IllegalStateException();
 562         }
 563         TransactionManager tm = manager.getCache("transactional-type")
 564                 .getAdvancedCache().getTransactionManager();
 565         if (tm == null) {
 566             return null;
 567         }
 568         return tm.getTransaction();
 569     }
 570
 571     @Override
 572     public boolean amIStandby() {
 573         EmbeddedCacheManager manager = this.cm;
 574         if (manager == null) {
 575             // In case we cannot fetch the information, lets assume we
 576             // are standby, so to have less responsibility.
 577             return true;
 578         }
 579         return (!manager.isCoordinator());
 580     }
 581
 582     private InetAddress addressToInetAddress(Address a) {
 583         EmbeddedCacheManager manager = this.cm;
 584         if ((manager == null) || (a == null)) {
 585             // In case we cannot fetch the information, lets assume we
 586             // are standby, so to have less responsibility.
 587             return null;
 588         }
 589         Transport t = manager.getTransport();
 590         if (t instanceof JGroupsTransport) {
 591             JGroupsTransport jt = (JGroupsTransport) t;
 592             Channel c = jt.getChannel();
 593             if (a instanceof JGroupsAddress) {
 594                 JGroupsAddress ja = (JGroupsAddress) a;
 595                 org.jgroups.Address phys = (org.jgroups.Address) c
 596                         .down(new Event(Event.GET_PHYSICAL_ADDRESS, ja
 597                                 .getJGroupsAddress()));
 598                 if (phys instanceof org.jgroups.stack.IpAddress) {
 599                     InetAddress bindAddress = ((org.jgroups.stack.IpAddress) phys)
 600                             .getIpAddress();
 601                     return bindAddress;
 602                 }
 603             }
 604         }
 605         return null;
 606     }
 607
 608     @Override
 609     public List<InetAddress> getClusteredControllers() {
 610         EmbeddedCacheManager manager = this.cm;
 611         if (manager == null) {
 612             return null;
 613         }
 614         List<Address> controllers = manager.getMembers();
 615         if ((controllers == null) || controllers.size() == 0) {
 616             return null;
 617         }
 618
 619         List<InetAddress> clusteredControllers = new ArrayList<InetAddress>();
 620         for (Address a : controllers) {
 621             InetAddress inetAddress = addressToInetAddress(a);
 622             if (inetAddress != null
 623                     && !inetAddress.getHostAddress().equals(loopbackAddress)) {
 624                 clusteredControllers.add(inetAddress);
 625             }
 626         }
 627         return clusteredControllers;
 628     }
 629
 630     @Override
 631     public InetAddress getMyAddress() {
 632         EmbeddedCacheManager manager = this.cm;
 633         if (manager == null) {
 634             return null;
 635         }
 636         return addressToInetAddress(manager.getAddress());
 637     }
 638
 639     @Override
 640     public InetAddress getActiveAddress() {
 641         EmbeddedCacheManager manager = this.cm;
 642         if (manager == null) {
 643             // In case we cannot fetch the information, lets assume we
 644             // are standby, so to have less responsibility.
 645             return null;
 646         }
 647
 648         return addressToInetAddress(manager.getCoordinator());
 649     }
 650
 651     @Override
 652     public void listenRoleChange(IListenRoleChange i)
 653             throws ListenRoleChangeAddException {
 654         EmbeddedCacheManager manager = this.cm;
 655         if (manager == null) {
 656             // In case we cannot fetch the information, lets assume we
 657             // are standby, so to have less responsibility.
 658             throw new ListenRoleChangeAddException();
 659         }
 660
 661         if (this.roleChangeListeners == null) {
 662             this.roleChangeListeners = new HashSet<IListenRoleChange>();
 663             this.cacheManagerListener = new ViewChangedListener(
 664                     this.roleChangeListeners);
 665             manager.addListener(this.cacheManagerListener);
 666         }
 667
 668         if (this.roleChangeListeners != null) {
 669             this.roleChangeListeners.add(i);
 670         }
 671     }
 672
 673     @Override
 674     public void unlistenRoleChange(IListenRoleChange i) {
 675         EmbeddedCacheManager manager = this.cm;
 676         if (manager == null) {
 677             // In case we cannot fetch the information, lets assume we
 678             // are standby, so to have less responsibility.
 679             return;
 680         }
 681
 682         if (this.roleChangeListeners != null) {
 683             this.roleChangeListeners.remove(i);
 684         }
 685
 686         if ((this.roleChangeListeners != null && this.roleChangeListeners
 687                 .isEmpty())
 688                 && (this.cacheManagerListener != null)) {
 689             manager.removeListener(this.cacheManagerListener);
 690             this.cacheManagerListener = null;
 691             this.roleChangeListeners = null;
 692         }
 693     }
 694
 695     @Listener
 696     public class ViewChangedListener {
 697         Set<IListenRoleChange> roleListeners;
 698
 699         public ViewChangedListener(Set<IListenRoleChange> s) {
 700             this.roleListeners = s;
 701         }
 702
 703         @ViewChanged
 704         public void viewChanged(ViewChangedEvent e) {
 705             for (IListenRoleChange i : this.roleListeners) {
 706                 i.newActiveAvailable();
 707             }
 708         }
 709     }
 710 }