Hi, My first mail didn't get a response, I admit it was posted using a webmail and was probably unreadable for some of you. My question is simple, I have an EJB3 MDB, I want to run the MDB only on the master node (where the JMS server resides). I tried several configurations (using a barrier on the deployers and putting the EJB3 .ear file in the deploy-hasingleton directory) but none works when the master fails. Any ideas on how to do that ? François.