JBoss.orgCommunity Documentation
This guide describes how to use the JTA interfaces for purely local transactions. This is a high-performance implementation, but you can only use it to execute transactions within the same process. If you need support for distributed transactions, the JTA needs to use the JTS. Another advantage of this approach is interoperability with other JTS-compliant transaction systems.
If you use the JTS and JTA interfaces to manage the same transactions, the JTA needs to be configured to be aware of the JTS. Otherwise, local transactions will be unaware of their JTS counterparts.
You need to do this configuration manually, because some applications may be using JBossTS in a purely local manner, or may need to differentiate between transactions managed by JTS and JTA.