Mostly I am wondering if anyone else has seen this behavior. We are upgrading our JBoss installation from 4.2.3 to 5.1.0. So far everything has worked great, but we are experiencing periodic service delays - that is, HTTP requests to the server will normally respond in under 1 second, but if the server is left running idle for some time (around 30 minutes or so), a request will hang for several minutes (usually no longer than 4 or 5 minutes). Once the request comes back, HTTP requests come back as normal again. A short while later, we'll see the same delay again. This server is used for our CXF services, and so it really only has a single war on it. Unfortunately, when things get stuck, we get any logging to see if anything is breaking. One interesting side effect is that if the server is stopped while hanging on a request, the request will come back, as if the request had been processed but gets stuck when the server actually goes to send the response.
I can provide more details if anyone has any insight.