Impact on performance because of "-XX:+UsePerfData" setting

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Performance and scalability: Impact on performance because of "-XX:+UsePerfData" setting

  1. We would like to monitor the usage of various generations (Young, permanent, old/tenured) of Java heap in our application server. To do this monitoring SUN has provided a tool called "Visual GC" and this tool mandates the use of "-XX:+UsePerfData". We would like to know if we have any performance impact if I use this setting. We are using IBM Websphere 5.1. Also could you please let me know if there is any other tool like "VisualGC" which will allow me to monitor various parts of GC with ease.
  2. Visual GC with IBM VM?[ Go to top ]

    Please forgive my ignorance, but does that mean that

    1) WebSphere can run on a Sun VM now, or does that mean
    2) that "Visual GC" can run with non-SUN VMs (IBM in that
       case)?
    3) both
    4) none of the above

    I don't know about Visual GC and I haven't used WebSphere
    for quite some time now (it used to run on IBM VM only in may days). Just curious ...

    Best regards,
    Stefan
  3. Typo[ Go to top ]

    may days => my days ;)
  4. Visual GC with IBM VM?[ Go to top ]

    I am running websphere on IBM VM only. Visual GC is working on IBM VM also.
  5. Visual GC with IBM VM?[ Go to top ]

    JVM Version that we are using

    java version "1.4.1_05"
    Java(TM) 2 Runtime Environment, Standard Edition (IBM build 1.4.1_05-b01)
  6. We would like to monitor the usage of various generations (Young, permanent, old/tenured) of Java heap in our application server. To do this monitoring SUN has provided a tool called "Visual GC" and this tool mandates the use of "-XX:+UsePerfData". We would like to know if we have any performance impact if I use this setting. We are using IBM Websphere 5.1. Also could you please let me know if there is any other tool like "VisualGC" which will allow me to monitor various parts of GC with ease.

    We have used for years the -verbosegc trace and all of the variations (including the one that shows the generations) and it doesn't seem to impact in the performance of the JVM.


    Jose R. Huerga

    http://www.terra.es/personal/jrhuerga
  7. try JProbe Memory debugger
  8. Thirumal - Using this option in Production is not advisable as the JVM will be busy making the Performance data available for the tool "VisualGC" which primarily connects to the server having this performance data and shows the data in a Visual Form.

    This is same as enabling a Profiler in Production.

    Try this in a staging environment and simulate with the load same as that of Production.

    -Jamil.