Tomcat sessions expiring unexpectedly

Issue

We are running tomcat application server that handle over 100 concurrent sessions. In the last 2 months the most active users noticed that sometimes they are getting kicked off from the system.

As I understood from the log tomcat sessions are getting expired without any reason.

I see no problems from the web application side. Is there any problem from the tomcat side?

Tomcat 6.0.18.

Solution

If there has been no code change triggering this, I would look at memory usage. This might be the effect of Tomcat running out of memory and invalidating sessions to recover.

If at all possible monitor garbage collections, and/or put surveillance on with jconsole Java Flight Recorder or jvisualvm.

Answered By - Thorbjørn Ravn Andersen