I'm looking at trying to maintain database synchronization across several separate databases which are all controlled by individual instances of JBoss.

Basically, each JBoss instance handles data input for it's own database, but certain database operations need to be replicated to all other database instances.

I'm considering doing this via JMS and MDBs. The way I see it, I'd need clients for each database which subscribe to topics on all of the other JBoss servers so that as data is entered into the database, messages are published to the topics which the clients then receive and pass along to the local JBoss instance.

The other option is to have only one JBoss instance responsible for messaging where all messages from all remote clients (most likely session EJBs in the remote servers) are sent and that JBoss server then publishes the message to everyone else.

I like the first approach as it's more symmetric than the second, but I'm not sure how I'd handle the dynamic addition of more remote databases and the resulting dynamic addition of listening clients on each server.

Very interested in your thoughts.