Do you really need maxThreads="1000" in your tomcat connector?? You should not set it that high, that might be reason your CPU is spiking when you do the load test, it will keep creating new threads for your incoming request. Even if you are expecting 500 concurrent request, i think 50 threads should be able to handle that. Also you can use acceptCount which is a queue for all your incoming connection requests when all possible request processing threads are in use. Refer to following URL for the bug which i was talking about https://jira.jboss.org/jira/browse/JBWS-2325 View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4241297#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...