Hi everybody, I'm trying to configure JBoss to make an EJB3 MDB run only on the JBoss cluster member in which the JMS server is running. I need a pure failover cluster configuration for JBoss. I tried several solutions using the 'barrier' dependency and trying to put the ejb ear file (alone and with te EJB deployers) in the deploy-hasingleton directory but none works. The only thing that would work would be (for what I understood) to put the barrier on the deployers, but then, when the old EJB deployers wakes up, it tries to deploy the EJB and not the EJB3Deployer, and this old EJB deployer is not able to deploy the EJB3 MDB. So, could anyone explain what is the cleanest way to clusterize such EJB3 MDB ? Thank you, François. Context : jboss-4.0.5.GA, Red Hat Enterprise Linux ES release 4 (Nahant Update 4).