Shashi Velur’s blog

Today, during load testing I saw one of those dreaded “java.lang.OutOfMemoryError: PermGen space” errors on our fairly large web application deployed in Tomcat running on Sun JDK 1.5.

We used to use the default (64m) for the perm space. I bumped it to 128 for now, until I can find some time to dig into this using JProfiler and JHAT.

I will be particularly looking at the amount of our classes loaded from WEB-INF/classes dir (we have a lot of generated classes from legacy code), Static references in our legacy code, Spring AOP/Hibernate CGLib usage and ThreadLocal usage in our application.

I found some useful information here:

• http://opensource.atlassian.com/confluence/spring/pages/viewpage.action?pageId=2669
• http://my.opera.com/karmazilla/blog/2007/09/29/return-of-the-permgen
• http://blogs.sun.com/fkieviet/entry/how_to_fix_the_dreaded
• http://blogs.sun.com/sundararajan/entry/querying_java_heap_with_oql

Technorati Tags: OutOfMemoryError, Performance tuning