public TopologyMonitorService() 
{

}

 public Vector getClusterNodes() 
{
      Vector view = null;
      try
      {
         InitialContext ctx = new InitialContext();
         String jndiName = "/HAPartition/" + partitionName;
         HAPartition partition = (HAPartition) ctx.lookup(jndiName);
         view = partition.getCurrentView();
      }
      catch(Exception e)
      {
         log.error("Failed to access HAPartition state", e);
      }
      return view;
}

 public String getPartitionName() 
{
      return (partition == null ? partitionName : partition.getPartitionName());
}

 public ObjectName getTriggerServiceName() 
{
      return triggerServiceName;
}

 public  void membershipChanged(Vector deadMembers,
    Vector newMembers,
    Vector allMembers) 
{
      MDC.put("RegexEventEvaluator", "End membershipChange.*");
      ArrayList removed = new ArrayList();
      ArrayList added = new ArrayList();
      ArrayList members = new ArrayList();
      changeLog.info("Begin membershipChanged info, hostname="+hostname);
      changeLog.info("DeadMembers: size="+deadMembers.size());
      for(int m = 0; m <  deadMembers.size(); m ++)
      {
         AddressPort addrInfo = getMemberAddress(deadMembers.get(m));
         removed.add(addrInfo);
         changeLog.info(addrInfo);
      }
      changeLog.info("NewMembers: size="+newMembers.size());
      for(int m = 0; m <  newMembers.size(); m ++)
      {
         AddressPort addrInfo = getMemberAddress(newMembers.get(m));
         added.add(addrInfo);
         changeLog.info(addrInfo);
      }
      changeLog.info("AllMembers: size="+allMembers.size());
      for(int m = 0; m <  allMembers.size(); m ++)
      {
         AddressPort addrInfo = getMemberAddress(allMembers.get(m));
         members.add(addrInfo);
         changeLog.info(addrInfo);
      }
      // Notify the trigger MBean
      if( triggerServiceName != null )
      {
         changeLog.info("Invoking trigger service: "+triggerServiceName);
         try
         {
            Object[] params = {removed, added, members, CHANGE_NAME};
            String[] sig = {"java.util.ArrayList", "java.util.ArrayList",
               "java.util.ArrayList", "java.lang.String"};
            server.invoke(triggerServiceName, "membershipChanged", params, sig);
         }
         catch(Throwable t)
         {
            changeLog.error("Failed to notify trigger service: "+triggerServiceName, t);
            log.debug("Failed to notify trigger service: "+triggerServiceName, t);
         }
      }
      changeLog.info("End membershipChanged info, hostname="+hostname);
      MDC.remove("RegexEventEvaluator");
}

Called when a new partition topology occurs.

 public  void setPartition(HAPartition partition) 
{
      this.partition = partition;
}

 public  void setPartitionName(String name) 
{
      this.partitionName = name;
}

 public  void setTriggerServiceName(ObjectName triggerServiceName) 
{
      this.triggerServiceName = triggerServiceName;
}

 protected  void startService() throws Exception 
{
      if (partition == null)
      {
         partition = HAPartitionLocator.getHAPartitionLocator().getHAPartition(partitionName, null);         
      }
      // Register as a listener of cluster membership changes
      partition.registerMembershipListener(this);
      log.info("Registered as MembershipListener");
      try
      {
         hostname = InetAddress.getLocalHost().getHostName();
      }
      catch(IOException e)
      {
         log.warn("Failed to lookup local hostname", e);
         hostname = "< unknown >";
      }
}

 protected  void stopService() throws Exception 
{
      partition.unregisterMembershipListener(this);
}