PermGen In Grails

Found this useful tidbit on Grails Facebook page - how to fix Grails permgen issues

• Hi ,default ram size occupied by jvm is 64MB you can increase it manually by the code given by santosh CATALINA_OPTS="-Xms256m -Xmx1024m -XX:MaxPermSize=256m". configure the above code in tomcat config file.

  Friday at 09:40 ·  ·  1
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  Prabhat Roy ‎2)Some time memory leak causes this problem, than abome wont work use profiler and chekout the code , dont include unnecessary jars and check the code module by module remove unneccessary object creation , if required call garbage collection explicitly to kill the useless objects. its bit difficult to debug.

  Friday at 09:44 ·  ·  1
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  Prabhat Roy ‎3)(a)Put JDBC driver in common/lib (as tomcat documentation says) and not in WEB-INF/lib
  (b)Don't put commons-logging into WEB-INF/lib since tomcat already bootstraps it

  Friday at 09:46 · 
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  Prabhat Roy new class objects get placed into the PermGen and thus occupy an ever increasing amount of space. Regardless of how large you make the PermGen space, it will inevitably top out after enough deployments. What you need to do is take measures to flush the PermGen so that you can stabilize its size. There are two JVM flags which handle this cleaning:
  
  -XX:+CMSPermGenSweepingEnabled
  This setting includes the PermGen in a garbage collection run. By default, the PermGen space is never included in garbage collection (and thus grows without bounds).
  
  -XX:+CMSClassUnloadingEnabled
  This setting tells the PermGen garbage collection sweep to take action on class objects. By default, class objects get an exemption, even when the PermGen space is being visited during a garabage collection.

  Friday at 09:47 · 
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  Prabhat Roy finally , in rare condition if nothing works than restart the server :)

  Friday at 09: