Application Server

I have been using Jboss As 6 a lot lately and it seems that with the new edition of application server from JBoss, it quite often runs into PermGen space issue. To rectify the problem each time, i had to bring down the development server only to bring it up again. It becomes quite haphazard and tedious especially with a slower machine.

A search on Google found some great articles, but the comments left behind by this particular user nailed it (Raghav http://blog.yannis-lionis.gr/?p=8). There were even some silly suggestions like switching to JRockit. Well ignore those.

PermGen space out of memory error when redeploying a JSF 2.0 web application through Maven Cargo plugin

To minimize this, one has to effectively “optimize” the JVM settings which JBoss runs on.

Step 1: Locate and open up run.conf

run.conf is usually found in the bin folder of your application server.

Location of my run.conf file

It is recommended that you modify the settings of the JVM through this file, and not through the .bat itself unless you have specific requirements.

Sample run.conf file

Step 2: Locate and change out the settings below the line that says “rem # JVM memory allocation pool parameters”

Original content

rem # JVM memory allocation pool parameters
set ...(deleted for simplicity)

Change it to:

rem # JVM memory allocation pool parameters
set "JAVA_OPTS=-Xms680m -Xmx680m -XX:PermSize=128m -XX:MaxPermSize=512m -XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled -XX:+CMSClassUnloadingEnabled"

Complete!

You now need only to restart your server to see the effects.

bash-3.2$ Calling C:\c\server\jbossas-vms\jboss-6.0.0.Final\bin\run.conf.bat
===============================================================================

  JBoss Bootstrap Environment

  JBOSS_HOME: C:\c\server\jbossas-vms\jboss-6.0.0.Final

  JAVA: C:\Program Files\Java\jdk1.6.0_22\bin\java

  JAVA_OPTS: -Dprogram.name=run.bat -Xms680m -Xmx680m -XX:PermSize=245m -XX:MaxPermSize=1024m -XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled -XX:+CMSClassUnloadingEnabled -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Dorg.jboss.resolver.warning=true -server

  CLASSPATH: C:\Program Files\Java\jdk1.6.0_22\lib\tools.jar;C:\c\server\jbossas-vms\jboss-6.0.0.Final\bin\run.jar

===============================================================================

Notice that JBoss AS echoes my new settings on start up.

Side Note

My PM (@Work) notes and shares that, in Microsoft Windows 32 bit environment, you would not be able to set a value higher than 1024 for your JVM in most cases. Look at this forum thread for some discussion on it http://www.minecraftforum.net/viewtopic.php?f=10&t=167193. Can someone elaborate some on this please? =p

Reference

http://blog.yannis-lionis.gr/?p=8