I am using JDK 5, JBoss 4.0.5GA and Windows. I'm fairly familiar with clustering, but barely with MBeans and sar archives.

I have gone through several posts, documentation and the wiki, and finally
managed to make a MBean service. I deployed the sar to farm/ it gets copied to all nodes. When I go to the web-console, I can see that the service has been successfully deployed on both the nodes. The jboss-service.xml of the sar contains:

 <mbean code="com.tcore.jboss.service.SingletonServiceExample"
 name="tcore.services:service=SingletonServiceExample">
 <depends>jboss.ha:service=HASingletonDeployer,type=Barrier</depends>
 <attribute name="Message">Message in the XML</attribute>
 </mbean>

Shouldn't the service automatically start on whichever node is the master?
I can manually invoke the start() operation which prints a diagnostic message to let me know that the service has started. But how do I make it work so that whichever node becomes master the service starts and when it loses master status, the service stops?

Following is the service code:

package com.tcore.jboss.service;

public interface SingletonServiceExampleMBean
{
 public String getMessage();
 public void setMessage(String message);

 public void printMessage();
 public boolean isTheMasterNode();

 public void startSingleton() throws Exception;
 public void stopSingleton();
}

package com.tcore.jboss.service;

public class SingletonServiceExample implements SingletonServiceExampleMBean
{

 private String message;
 private boolean theMasterNode = false;

 public void startSingleton() throws Exception
 {
 theMasterNode = true;
 message = "I have been started! " + theMasterNode;
 System.out.println("Starting with message: " + message);
 }

 public void stopSingleton()
 {
 theMasterNode = false;
 message = "I have been stopped!" + theMasterNode;
 System.out.println("Stopping with message: " + message);
 }

 public String getMessage()
 { return message; }

 public void setMessage(String message)
 { this.message = message; }

 public void printMessage()
 { System.out.println(message); }

 public boolean isTheMasterNode()
 { return theMasterNode; }

}

Thanks!