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3 Replies Latest reply: Jul 30, 2012 3:43 AM by 951741 RSS

Stuck Thread, Heap Usage, OOM etc

951741 Newbie
Currently Being Moderated
Hi

I am a Performance Engineer, not so familar with Weblogic. I have following questions, appreciate your help.

- What weblogic does with the Stuck Thread besides reporting into log file. I mean does it kill it leave it as it is. I see Stuck messages multiple time in my nohup log file, it is logging the complete stck trace so i know where the issue is, so no worries there.
Line 7269: <Jul 23, 2012 11:01:19 AM EDT> <Error> <WebLogicServer> <BEA-000337> <[STUCK] ExecuteThread: '10' for queue: 'weblogic.kernel.Default (self-tuning)' has been busy for "697" seconds working on the request "weblogic.servlet.internal.ServletRequestImpl@220b5f64[

- I see below messages related to free heap in managed server log file. I want to why this messges not coming at regular interval, I don't find any configuration settings in admin console related to this messages.
Line 5: ####<Jun 25, 2012 2:38:05 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340649485139> <BEA-310002> <84% of the total memory in the server is free>
     Line 19: ####<Jun 25, 2012 2:44:55 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340649895820> <BEA-310002> <35% of the total memory in the server is free>
     Line 20: ####<Jun 25, 2012 2:45:46 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340649946682> <BEA-310002> <13% of the total memory in the server is free>
     Line 35: ####<Jun 25, 2012 2:47:48 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340650068201> <BEA-310002> <62% of the total memory in the server is free>
     Line 225: ####<Jun 25, 2012 4:46:48 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340657208760> <BEA-310002> <51% of the total memory in the server is free>
     Line 228: ####<Jun 25, 2012 4:52:48 PM EDT> <Info> <Health> <nyl01a-4803> <fxecom1> <weblogic.GCMonitor> <<anonymous>> <> <> <1340657568787> <BEA-310002> <65% of the total memory in the server is free>
- In above message related to free memeory, I guess it is reporting the free heap in JVM, if so which are of JVM is it indicating to PSYoungGen, PSOldGen or PSPermGen

Thanks
-nilesh
  • 1. Re: Stuck Thread, Heap Usage, OOM etc
    Kalyan Pasupuleti-Oracle Expert
    Currently Being Moderated
    Hi Nilesh,

    It only talk about your total Heap which include Young + Old space.

    Perm Gen will be the different one.

    If you allocating XMX 1024m then it total 1GB of Heap you set and when you set -XX:MaxPermSize=256m then additional memory setting for 256m.

    when you include both it come 1.25G.

    But when Memory MBean which shows on log is based only on Heap but not on Perm space.

    Regards,
    Kal
  • 2. Re: Stuck Thread, Heap Usage, OOM etc
    murali veligeti - oracle Expert
    Currently Being Moderated
    Hi Nilesh,

    Q) What weblogic does with the Stuck Thread besides reporting into log file. I mean does it kill it leave it as it is ?
    A) WebLogic Server diagnoses a thread as stuck if it is continually working (not idle) for a set period of time. You can configure the time period in Admin Console.You can tune a server's thread detection behavior by changing the length of time before a thread is diagnosed as stuck, and by changing the frequency with which the server checks for stuck threads. WebLogic Server automatically detects when a thread in an execute queue becomes stuck. Just because weblogic throws the thread as stuck it doen't mean that it will kill. It will not kill the stuck threads. The thread still continues. It is for the user to identify the thread is taking more time. Stuck thread means it cannot complete its current work or accept new work, the server logs a message each time it diagnoses a stuck thread.

    Q) I want to why this messges not coming at regular interval, I don't find any configuration settings in admin console related to this messages ?
    A) These messages are just for your information and these will not show at regular intervals. These messages will be shown when there GC is happening or while showing about the health of the server.

    Q) If so which are of JVM is it indicating to PSYoungGen, PSOldGen or PSPermGen?
    A) For PermGen the setting is XX:MaxPermSize. MaxPermSize specifies the the maximum size for the permanent generation heap, a heap that holds objects such as classes and methods
    For younGen the setting is XX:MaxNewSize. Maximum size of new generation (in bytes). Since 1.4, MaxNewSize is computed as a function of NewRatio

    Thanks & Regards,
    Murali.
    ============
  • 3. Re: Stuck Thread, Heap Usage, OOM etc
    951741 Newbie
    Currently Being Moderated
    Thanks Kalyan and Murali

    Murali

    Q) I want to knnow why this messges not coming at regular interval, I don't find any configuration settings in admin console related to this messages ?
    A) These messages are just for your information and these will not show at regular intervals. These messages will be shown when there GC is happening or while showing about the health of the server.

    you mentioned two reasons for the message related to free heap. The first one sounds sensible, hope you referring to major GC here which cleans the young and old both. I am not 100% convinced about the second reason, if this is related to heath check there must be configuration settings where we could mention how frequently it should check the health of the server.

    it will be helpful if you could point me to related documentation.

    Thanks
    -nilesh

    Edited by: 948738 on 30-Jul-2012 03:42

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