Can 2 unclustered JBoss instances share the same DB tables f

[lispnik]

We have a configuration consisting of 2 JBoss instances (unclustered) and one database. Each instance runs the same application. The application includes an MDB. Is it possible for each JBoss instance to use the same DB tables for messaging queues? Would there be a risk that messages would be processed twice as they're take from the queue?

[wdfink]

we do this, but without JMS..
just for CMP and EJB-Timers.
For CMP it is not a risk if you aren't use CMP-caching.
The timer tables must different (if you use timer), this can be configured in version 4.2. Otherwise ejbtimer services are started twice.

JMS depends on what you using:
JBossMQ -> deployed as HASingleton in a cluster
not able to run in cluster or separated nodes like yours
EXECPT: you ensure that the provider/consumer use a message-property to ensure it.
I think that works but it is a dirty hack IMHO

JBossMessaging -> is cluster ready.
All nodes are useing the same DB (in a cluster) but each node needs it's unique id to handle the queue.
I don't play around with it, so I'm not sure how it works. But my dirty hack should work as well.