4 Replies Latest reply on Aug 12, 2005 7:19 AM by Kyosuke Kirimoto

    High CPU usage by Jboss process with default setting

    Kyosuke Kirimoto Newbie

      Hi,

      I am using Jboss 3.0.1, however CPU usage by its process become high( about 8% ) once every minute, although any Web access is not done.
      Does anyone know about this spike?

      I investigated what system call is made by jboss process at the time of the spike with "tusc" command.

      The following is the result of tusc.

      # tusc -s open -i PID
      npen("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/conf/log4j.xml", O_RDONLY|O_LARGEFILE, 0666) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/conf/log4j.xml", O_RDONLY|O_LARGEFILE, 0666) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 85
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70
      open("jboss-3.0.1/server/A/deploy", O_RDONLY, 0130100) = 70

      The output is done every 5 seconds, and in this case, only one line was output every output.
      I confirmed the spike occurs whenever the return value of open() is changed 85 to 70.
      So, the change of the return value is done once every minute.
      However I couldn't figure out the reason of the spike.

      Next, I tried to confirm how the latest version of Jboss behaves.
      I installed jboss-4.0.2, started it up, and confirmed if spike happens.
      (Any configuration to jboss was not done.)
      As the result, I confirmed Jboss process's CPU usage become high up to about 16% once every minute.

      Therefore I believe this spike is Jboss's default behavior.
      Why does this happen and is there any workaround for this spike?

      Any information is appreciated.

      Thanks,
      Kyosuke