Are you sure that you dont have any connection leaks in your application? Also, you say that you are running a 15+ hour test on JBoss, so is 100 max-pool-size sufficient for your application? And the logs that you posted show a blocking timeout of 5000 ms where as the -ds.xml configuration that you posted has 30000 ms. So are you sure you did the changes at the right place and they are being picked up? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4122497#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...