1) At the moment, you are correct, an exception is thrown. This should propagate up to the caller though. 2) Yes again; state is transferred when new buddies join (or shunned ones rejoin). No assumptions are made as to the fact that the buddy may already have some state. 3) We need to think about what the correct behaviour here should be. You are correct in that the current behaviour is incorrect. 4) Agreed. The thing is, 1) How do we detect a shun? Do we have a JGroups notification for this? 2) How can we transparently deal with the merge? Simple case of wiping the joiner's in-memory cache? :( View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3977492#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...