If you have the following warning in your JBoss 6 logs:
WARN [org.hornetq.core.cluster.impl.DiscoveryGroupImpl] There are more than one servers on the network broadcasting the same node id. You will see this message exactly once (per node) if a node is restarted, in which case it can be safely ignored. But if it is logged continuously it means you really do have more than one node on the same network active concurrently with the same node id. This could occur if you have a backup node active at the same time as its live node.
You just have to delete the contents of the /server//data/hornetq/ directory, as you most probably will be using a copy of the exactly the same instance of the JBoss installation that’s causing those warnings. At startup, HornetQ geneartes the node ID and stores it in a file. If you copy that file and the JBoss installation surrounding it, it won’t regenerate the node ID and you will have two servers with the same node ID on the network, hence the pesky warning in your log files.