1 Reply Latest reply on Jun 19, 2009 1:31 PM by Peter Johnson

    About UseParallelOldGC

    Chiu Tony Newbie

      I am running a cluster JBoss servers.
      Both server has 4 CPUs, dual cores. i.e. 8 logical CPUs.

      I want to tune the JVM setting and I found that I can use the following parameters:

      +UseParallelOldGC -XX:ParallelGCThreads

      I did some load test with different number of ParallelGCThreads.
      However, I was surprised from the load test result that, the Full GC time for the UseParallelOldGC is much longer than I didn't use it. E.g.

      A) Parallel Old GC = 7
      4.1747870 secs

      B) Parallel Old GC = 3
      4.2135090 secs

      C) No Parallel Old GC
      2.7176180 secs

      Does anyone know any reason why the Parallel GC can perform poor?