I suspect this is a side-effect of http://jira.jboss.com/jira/browse/JBAS-4919. When you do a clean shutdown, B is getting a message telling it the *com.unique.system.mbean:service=MyService-HASingletonController service* is undeployed on A, but A is still in the view, since A overall hasn't shut down yet. Can you try your HASingletonElectionPolicy, but kill -9 A instead of a clean shutdown and let me know what happens? Obviously that's not a solution, but it can help confirm my thinking. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4119144#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...