It is late on a Friday afternoon, and your web application has stopped responding to requests. The server is still reachable, and the Apache Tomcat process is still running–there are no errors in the logs. You want to go home but you can’t until it is fixed. What do you do? If your answer is “restart Tomcat and hope it stays up until Monday,” then this article is for you. Rather than keeping your fingers crossed and hoping you don’t get an angry call from your boss over the weekend, this article will provide you with some simple steps you can take to diagnose the problem.