In our system, we have each clients data in a separate DB instance. We're using JPA (via hibernate) on top of that to get at the data. The problem here is that for each client DB supported by one of our jboss servers, we have to have an instance of EntityManagerFactory compete with an Ejb3Configuration instance. Each config instance takes up around 30-40 MBs of permanent space, so if we have have 1000 client DBs supported by a jboss instance, it takes up a hugh amount of memory for information that will always be the same (the DB schemas are always the exact same in each client DB) across all EntityManagerFactory instances. So what I want to know is if there is a way to only have one instance of Ejb3Configuration that can be shared across all of the EntityManagerFactory instances that are spawning my EntityManagers. This would be huge as it would help me save many gigs of perm space.