Performance Issue

[rlynn]

Forgive me if I'm posting this in the wrong forum but I'm not sure where it belongs. We're seeing some rather strange behavior when running JBoss2.4.3/Tomcat3.2.3 on Solaris 2.7. We've split the Web Server on a separate machine to isolate the problem. Here's the issue...

When we run a load test of (100-200) users against our application JSP / Servlets / EJBs, the app seems to perform pretty well. However, every 30 minutes (Without fail), the machine seems to come to a grinding halt - no cpu activity, very little disk, etc. During this time you cannot access the application from your web browser. After a few minutes of resting the app finally comes back and begins performing well again.

One thing I though of was the session timeout, so I changed it to 15 minutes. However, the probably still seems to happen in 30 minute intervals. Any ideas?

Ralph

[rlynn]

It looks like we found the problem on this one. Our load test tool creates a new session on every iteration of a test run. because of this, we create several thousand stateful session beans during a given test scenario. These don't get cleaned up until the bean cleanup thread runs which is based on the remover-period that is set to 30 minutes by default. This explains our 30 minute performance problem.

Now, I have a question about this. It seems that when this thread runs it basically takes over the app and all other threads are basically in a waiting state. Is this a known problem or expected behavior? I would expect this to be a low priority thread because its only doing cleanup work in the background. Anyone else see this?