anonymous wrote : Well it works, right out of the box: no EntityManager.clear or merge calls needed in the "original" thread - but I have no idea if this is safe, supposed to work or should be avoided at all costs Okay, avoid! First I thought it works, but now it doesn't: so if it worked at all (was quite tired when I tried it), its absolutely unreliable. For the record: I moved to a different approach: 1st) cache my persistent entities 2nd) detach from them 3rd) work on the cached state, update them as I need to (even from different threads) 4th) update the cached state periodically with a Timer Thats accurate enough for me and I can react on events like callbacks immediately. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3964477#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...