For a nested structure, again, I think we need the concept of ownership and relatively the same code that already exists with the proxy context. At first, the parent SFSB owns all the children. If a child is "touched" by an invocation, it must ping the parent to replicate the whole tree: parent and all its children. If the parent is removed, a child is picked as the new "parent". As for your concurrency problem. I don't think we should code for this and document that that scenario is not supported. SFSBs are supposed to be used by one client, not multiple clients concurrently. This will make things easier IMO. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4008905#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...