500 Internal Server Error PermGen space

Question

Almost every time I redeploy my application, I get a
500 Internal Server Error
java.lang.OutOfMemoryError: PermGen space
response from the application server. To recover, I have to restart the application server. Any ideas on how to prevent this error?
thanks,
chas

Answer 1

I should add some more helpful information, maybe :)
I get the permgen OutOfMemory while redeploying an app, most commonly. Since there's no lifecycle event when an application is stopped, as far as I know, our singletons are never cleaned up from the old classloader. So it's quite possible the garbage collector or classloader are holding onto stale references to objects or classes from the now stopped and un-deployed application. I know our apps create a lot of objects under those singletons.
Maybe this is the key to fixing the error? I have noticed 10.1.3 gives helpful-looking warnings on standard error:
07/01/19 15:03:54 com.example.propmgr.PropertyManagerException: An Exception has occured while loading the following
file: timeout.propertiesClassLoader "gm.root:0.0.0" (from <application> in /C:/oc4j101310/j2ee/gm/applications/gm/): This
loader has been closed and should not be in use.