OK, thanks for the details. I was hoping you'd tell me something that would tell me where you're going wrong, but you've basically got a regular client that does JNDI lookups of clustered EJBs. Shouldn't matter whether you do a lookup in local JNDI or HA-JNDI, either way you should get a proxy that tracks changes in the cluster topology. A simple explanation would be that the servers aren't clustering properly, but in some cases you are getting proxies that can communicate with both servers, so that tells me that there is communication. And once a server knows about another, if the communication is cut off the surviving server should detect that and update its proxies. And you're not seeing that either. I'll have to think a bit about this to try to come up with an approach to diagnosing the issue. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3971319#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...