Commit option A can boost your Entity Bean but what happens when running in a cluster ? in a cluster configuration more than one JBoss node will access the same database. Furthermore, they will not only read data, but may also update the db store.Consequently, we now have as many points of write access to the database as we have JBoss instances in the cluster.
For these scenarios, JBoss incorporates a handy tool: the cache invalidation framework. It provides automatic invalidation of cache entries in a single node or across a cluster of JBoss instances. As soon as an entity bean is modified on a node, an invalidation message is automatically sent to all related containers in the cluster and the related entry is removed from the cache. The next time the data is required by a node, it will not be found in cache, and will be reloaded from the database.
In order to activate it, add to your Entity Bean the cache-invalidation tag.