We have an application running on Jboss AS 7.1.1 and uses EJB 3. We are intermittently seeing the following errors
javax.ejb.EJBException: JBAS014516
This happens, when the configured EJB pool is exhausted - means that all EJBs are currently "in use" (=processing). Look for long running invocations within your EJBs. It seems that the invocations take longer than 5 minutes in your case.