OK - I'll initially modify HAServiceMBeanSupport.callMethodOnPartition() to return an ArrayList. That shouldn't break any existing code and will make the RPC results available to interested clients. I agree that it would be preferable to have HACluster.callMethodOnCluster() return a List. Changing this will break callers in the cluster module and possibly in another module or two. Of course, it will also break any client code which utilizes this RPC support. I won't make this change unless we decide to proceed but I'll take a quick look at the effect on JBoss code. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4065327#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...