A while ago I was confronted with a WebLogic server which did not want to start. The log files did not give an indication of what was wrong. I tried the usual suspects such as clearing the tmp and removing lok files but they did solve the issue. How to proceed? In this blog article I'll provide an example of how such an issue can be debugged.
A stuck thread is a thread which takes longer than the configured stuck thread max wait time (600 seconds by default). To simulate a stuck thread issue I created a simple servlet which does a Thread.sleep upon a request. I'll show how to use various tools to detect the servlet causing the problem and even identity the specific request which causes the code to malfunction. A similar mechanism can be used to debug for example JDBC issues and can help in the identification of which connection causes an issue. The tools used do not require the server to be fully started.
Monday, November 23, 2015
Monday, November 2, 2015