A monitoring tool like App Dynamics will give you lots of info but some quicker tests you can do with built-in tools:
- Check that the CPU on your server is not at 100% - Use jstack to get a stack dump: http://docs.oracle.com/javase/7/docs/technotes/tools/share/jstack.html . I will take a couple stack traces with a few seconds in between each and then see if all my threads are stuck somewhere. - Use jstat (with the gcutil option) to print out Garbage Collection issues: https://docs.oracle.com/javase/8/docs/technotes/tools/unix/jstat.html . Something to look for is lots of full GCs or really long GC times. The VisualVM tool can call the above utilities and show GC info in a graphical manner. It might be easy to use depending on the network between your app and where you run VisualVM. -Dave -----Original Message----- From: Cohen, Laurence [mailto:lco...@novetta.com] Sent: Monday, November 16, 2015 3:43 PM To: Tomcat Users List Subject: Tomcat Application Stops Responding Hi Everyone, Are there any tools that come with Java that I can use to troubleshoot an intermittent problem we are having? The problem is that several times a day, our Tomcat applications will stop responding and I'll have to restart them to get them working again. It's gotten to the point where I have written a script which does a wget every 10 minutes against an object in the DB, and if it fails, it will restart our apps. I've also done some statistics gathering and imported them into a spreadsheet so I can see what is going on at the time the system is crashing. All I can see is that the Tomcat connections are spiking. We are running Tomcat 7.0.59 with two apps, Postgres 9.2 on the backend which is not administered by us, and httpd on the front end, 2.2.15. The httpd server and app server are RHEL6. Thanks, Larry This e-mail and any files transmitted with it are confidential, may contain sensitive information, and are intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error, please notify the sender by reply e-mail immediately and destroy all copies of the e-mail and any attachments. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
