2 Replies Latest reply on Jun 19, 2008 3:13 PM by Peter Johnson

    JBOSS hangs and logging stops

    Danny Willems Newbie

      Hello,

      I'm not sure I'm posting in the correct forum, so my apologies if I'm not.

      Our JBOSS server (version 4.2.2) is running as a service (using a wrapper) on a Windows 2003 SP2 server.

      Since this week our production JBOSS server seems to freeze from time to time (at average once a day) and clients can no longer connect. If we reboot the JBOSS service everything is fine again, but off course we lose all the sessions that were active. If we do nothing the server starts working again after about 10 minutes (at least it did today) and all the sessions are still there so the users can continue working without a problem.

      During the time of the freeze we can still connect to the machine and the only thing we can observe that is strange is that absolutely nothing is written to the JBOSS log files. We have a wrapper log and a server log where during normal operations multiple entries get added every second. But during the freeze nothing gets written to them. Also there are no errors in the logs just before the freeze. When JBOSS continues we do see some errors related to http and apache, but other than this everything is working correctly again.

      When checking the resource utilization on the machine we observe the following:
      * the memory usage of the java process increases to almost the maximum set in the wrapper, while the JMX attribute FreeMemory shows that a lot of memory gets freed (from 200MB free to 700MB free).
      * there is very heavy disk I/O at the beginning of the freeze
      * The JMX attribute ActiveThreadCount drops from 200 to around 50
      * There is no big change visible in CPU usage.

      I find this a very strange problem as we do not get any errors during the freeze, only complete silence. I hope there is someone who can help us.

      Thanks in advance.