On Feb 26, 2009, at 5:58 AM, Stella Lok wrote:
Hi, I am using WAS CE 2.0.0.2 with ActiveMQ 5.2.0. While doing load testing, I encountered situations when the web server (which is the Tomcat embedded in WAS CE) permanently (until restart) stopped responding to any HTTP requests (the catalina log stops logging new requests), and none of the apps nor the admin console can be accessed anymore. When that happens, the WAS CE java process' CPU utilization would invariably be permanently stuck at around the 50% level, even if I completely stop accessing the server. I did a thread dump whenever this occurred, and most of the time I do not see any blocked threads, only runnable, parked and waiting-on-condition threads. Once, I was able to see that there were 4 blocked ActiveMQ threads, though I'm not sure if this is related. I would be most grateful if someone could help guide me to possible causes of the problem.
Hmm. Do you still have the thread dumps? Esp. the one showing the blocked AMQ threads? Is this a 2 CPU machine (e.g. a single dual core processor?) Sounds like you have a single thread spinning. A thread dump should help identify the culprit... Are you running on Sun or IBM JSE?
--kevan