Dealing with “java.lang.OutOfMemoryError: PermGen space” error

Question

I am coding for a web application with a typical Hibernate/JPA + IceFaces/JSF application running on Tomcat 6 and JDK 1.6. It is throwing the following error

java.lang.OutOfMemoryError: PermGen space

Apparently, this can occur after redeploying an application a few times. 

Answer 1

You have to add these flags to the JVM command line when Tomcat is started:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled

You can do that by shutting down the tomcat service, then going into the tomcat/bin directory and running tomcat6w.exe. Under the “Java” tab, add the arguments to the “Java Options” box. Click “OK” and then restart the service.

If you get an error the specified service does not exist as an installed service you should run:

tomcat6w //ES//servicename

Where servicename is the name of the server as viewed in services.msc

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