MustGather: 100% CPU Usage on HP-UX
 Technote (FAQ)
 
Problem
MustGather for problems with the WebSphere® Application Server 100% CPU Usage on HP-UX. Gathering this information before calling IBM® support helps familiarize you with the troubleshooting process and saves you time.

This list documents what is needed to begin troubleshooting a Java™ Virtual Machine (JVM™) that causes 100% CPU usage or an unusually high percentage on HP-UX.
 
Solution
If you have already contacted support, continue on to the component-specific MustGather information. Otherwise, click: MustGather: Read first for all WebSphere Application Server products.


100% CPU usage specific MustGather information
Set up:
  1. Install HP glanceplus, if not already installed on system. Directions to install glanceplus:
    http://www.openview.hp.com/products/gplus/index.html

  2. If the system does not currently have high CPU, perform the following four commands:

    netstat -p tcp > netstat_normal.out
    vmstat 5 60 > vmstat_normal.out
    top -s5 -d60 > top_normal.out
    sar -o sarfile 5 60


  3. This takes 60 samples, each one five seconds apart (for a total of five minutes), saving the binary output to sarfile. After sar has collected the data, produce a report using the command:

    sar -Af sarfile >sar_normal.out

  4. Add following JVM option to the Java process that is causing high CPU. This option requires WebSphere Application Server restart.

    -Xeprof:file=filename


During high CPU usage, issue the following commands in parallel from four terminal windows:
  1. glance -adviser_only -syntax /opt/perf/examples/adviser/thread_activity
    -j60 > /tmp/glanceout


    Be careful as this file grows large quickly; make sure you have enough disk space allocated to /tmp directory.

  2. ./wscpuhp.sh PID

    where PID is the process ID of the JVM that is causing high CPU The wscpuhp script is attached below.

  3. ./vmstat.sh

  4. ./top.sh

  5. Collect the following files:
    • For V6.0 release:
      • Files in install_root/profiles/profile_name>/logs/server_name directory
      • FFDC logs from install_root/profiles/profile_name/logs/ffdc directory
    • For V5.0 and V5.1 releases:
      • Files in install_root/logs/server directory
      • FFDC logs from install_root/logs directory
    • For V4.0 release:
      • Files in install_root/logs directory.
      • The stdout and stderr files
    • For all releases:
      • All of the *.out files created by the above commands
      • Output of glanceout and Xeprof

  6. Follow instructions to send diagnostic information to IBM support.


For a listing of all technotes, downloads, and educational materials specific to the 100% CPU Usage component, search the WebSphere Application Server support site.
 
Related information
Submitting information to IBM support
Steps to getting support
MustGather: Readme first
Troubleshooting guide
 
wascpuhp.shtop.shvmstat.sh
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > 100% CPU Usage
Operating system(s): HP-UX
Software version: 6.0
Software edition:
Reference #: 1166017
IBM Group: Software Group
Modified date: Oct 25, 2005