PermGen Error during deployment or when application is running

[amarbhat]

Hello All,

   Our environment has :-

    JBoss AS version 5.1.0.GA, JDK version jre1.6.0_21 and linux OS version 2.6.18-194.17.1.el5 x86_64 x86_64 x86_64 GNU/Linux.

Our application uses Spring Integration, Hibernate, HornetQ, JAX-WS and size of the war file is approximately 18 to 19 MB.

   We are encountering PermGem OutOfMemory errors either during application deployment or randomly in the middle of the day when the

application is running on the server. We read several articles on the web and have the following arguments passed during server startup:-

-server -Xms2048m -Xmx2048m -XX:PermSize=128m -XX:MaxPermSize=512m -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -Xrs

  We originally had the MaxPermSize parameter set to 256m and we increased it to 512m. After this change the PermGen error has

gone down drastically but we feel that this is not a permanent solution. Is there a permanent solution to this PermGen problem on JBoss ?.

If yes, please let us know and if the arguments' we are currently passing need any changes or tweaking.

Thanks,

Amar

[wdfink]

The PermGenSize depends to your application and some other parameters.

There is no general answer, you have to analyse the behaviour.

Helpful starting point is the Java GC site http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html

From Peter Johnson is an article here http://www.cmg.org/cgi-bin/search.cgi?q=java+peter+johnson&x=30&y=10

If the problem is reproducable the java tools jconsole, visualgc, jstat or jhat are helpful. We use jProfiler at the moment, but there are also different Java profiling tools available.