Debugging applications that hang

Possible cause: The WebSphere variable transaction_defaultTimeout might have a value too large.
Caused by: Loop in the application JVM runs out of heap storage, if you are running Java in a servant (region)
Look for:
  • Environment variable that handles how long the application runs before timeout
  • Timeout-related minor codes:
    • C9C21047
    • C9C2110F
    • C9C21110
    • C9C21111
    • C9C21112
    • C9C21113
    • C9C21114
    • C9C21190
    • C9C21191
    • C9C21192
    • C9C21809
    • C9C21892
    • C9C21893
    • C9C22013
  • ABEND EC3, reason codes 0413002 through 04130007
  • resource messages on the console

    Example: DB2 deadlock messages on the z/OS console

  • A wait beyond the timeout value length with no timeout
  • Any error messages from JVM in the job log of the failed servant (region)
Actions:
  • Analyze with IPCS to determine whether or not the servant (region) was looping (application code loop) or waiting (maybe the runtime failed).
    • Use the DUMP command to get a console dump of the servant and its controller.
  • If you were utilizing JRAS, look at the JRAS CTRACE entries:
    • If the application code was looping, you may see the same entry repeating.
  • Ensure that CTRACE writer is on and take a SVC dump at the approximate time of hang.
  • Use the display command to determine the state of the server.
  • Through the Administrative console, set the WebSphere variable to debug the JVM; this setting passes information to the JVM and turns on the high-level messages for you to examine.
  • Look for error message or Java stack traces that might indicate an OUT_OF_MEMORY condition.
  • Use application monitoring tools, such as WebSphere Studio Application Monitor (WSAM) or Jinsight, to look for application memory leaks.


For current information available from IBM Support on known problems and their resolution, see the IBM Support page.

IBM Support has documents that can save you time gathering information needed to resolve this problem. Before opening a PMR, see the IBM Support page.




Searchable topic ID:   rtrb_debugapplhang
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
http://publib.boulder.ibm.com/infocenter/wasinfo/index.jsp?topic=/com.ibm.websphere.zseries.doc/info/zseries/ae/rtrb_debugapplhang.html

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