Yes, if the request goes into an infinite loop, that request will continue to hold onto the thread. I have seen several thread dump where that has been the case. If you get enough of such requests, eventually all threads will be in use. I know of no way within jbossas to kill such a thread. You could beat up on the developer though and tell him/her not to do that. If there is a long running request, using an alternate means to process the request might be preferable, for example, use jms to process the request asynchronously.