I think you can give it a try for your Data Base related problem.
In my project some of the requests take almost 4 minutes to respond and it appears that there are too many requests made to the database.
try to increase the pool size in server/xyz/deploy/xyz-ds.xml which would look like as :-
<!-- The minimum connections in a pool/sub-pool. Pools are lazily constructed on first use --> <min-pool-size>5</min-pool-size> <!-- The maximum connections in a pool/sub-pool --> <max-pool-size>20</max-pool-size>
Be sure that you are closing all the database connections properly.
or check you have not commented the default connection closer by Jboss. :)
I'm using the caching mechanism in jboss with persistent entities.
If you have not already done so, it might be worth migrating your application to use ejb3's persistence. There are tools out there that will assist you with converting an existing db schema to ejb3/hibernate pojos. From here it is a matter of a few annotations and xml tags to utilize the L2 cache to stop your application making excessive duplicate sql queries.