Frank wrote : Why do I need a connection for every request? Because every request that is made will cause some interaction with the database. Therefore, each request needs a connection. Also, you have to realize that every connection in the database creates a new thread in the database. You can monitor the number of connections that the database has - perhaps you have reached the limit on the number of threads it can run. What OS are you using? A better approach might be to have only a few connection, say setting max connections to 100, and see how far you can push the IR. Keep track of the queue depth (that will tell you how many app server threads are waiting for an available database connection), and then increase the database connections by a small number, say 20, at a time. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4224188#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...