1 Reply Latest reply on Nov 5, 2007 11:48 AM by Peter Johnson

    too many system gc calls?

    André Dobell Newbie


      I'm using a jboss 4.2.0 server in a machine with theese features:

      - RAM: 4 GB
      - CPU: 2 processors ( Intel Xeon E5320 @ 1.86GHz)
      - Operating system: Centos 5.5
      - Java: jdk_1.6.0_03
      - Jboss: 4.2.0_GA

      The jvm parameters are:

      -Xms128m -Xmx512m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Dcom.sun.management.jmxremote

      If i use jconsole I can see that the memory is free almos every minute althoug the heap is less than 80Mb used and nobody is using the only one application deployed in server.

      If I set the parameters:

      -Xms512m -Xmx512m -Xmn150m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Dcom.sun.management.jmxremote

      Memory is just free when the heap goes to 150Mb, so gc is called every 30 minutes more or less.

      The question is, what parameters are good? The first ones or the second ones?
      What aditional parameters can I use to get better performance and heap, jvm tuning?