Information on the "500 Servlet Exception" error message

The Resin application server, used by Lunarpages hosting, will sometimes report the following error:

500 Servlet Exception
java.lang.OutOfMemoryError: PermGen space

This will subsequently cause another error:

500 Servlet Exception
java.lang.OutOfMemoryError: Java heap space

According to Resin's web site this will generally appear when new code is uploaded [1]. It usually takes 15-20 minutes to clear up after the server deploys the new code. Alternately, you can force a redeploy of the JSPs to reset the project.

From the Resin page:

[The OutOfMemoryError: PermGen space] error occurs only after the redeployment and restart of new applications, ... the likely cause is that the JVM cannot garbage collect old classes that are replaced because there are references to the old classes