...Pertence tool can also be used for finding out threading issues. Just write a test that uses the component you need to test for threading issues and assign load of threads to the test.
Thanks to my employer (Nokia) for letting me publish the initial version of this tool as open-source!
A Portable Thin Client & Server Pair for XA / 2PC Testing
A portable testing tool to validate the configuration of XA and two-phase commit for Java EE 6 Containers. The tool permits the stress-testing, performance characterization and correct transaction semantics of distributed transactions across Three XA resource managers by Exception Injection. The thin-client can be run from the command-line or inside the IDE. The server side component includes EJB packaging and some simple Web servlet support for retrieving diagnostic and performance data from the testbed.