IBM Support

IT28733: MQ V5.3 FOR NONSTOP WMQTRIG SCRIPT LEADS TO UNPREDICTABE TRIGGERING RESULT DUE TO HANDLING OF PARAM FILE.

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APAR status

  • Closed as program error.

Error description

  • The mqtrig (or wmqtrig in WebSphere MQ) is  an IBM MQ script
    that is used to trigger Guardian programs and TACL commands or
    scripts. The flow of actions goes as follow:
    - The script creates a param file,
    - The script calls gtacl,
    - gtacl reads the param file, and creates an environment from
    the param file content and starts the Guardian application with
    that environment.
    There is a possibility when the script appends another
    enviroment to an existing param file. That leads to
    unpredictable triggering results or no triggering at all.
    

Local fix

Problem summary

  •   Under certain conditions the MQ trigger script
    reuses an existing gtacl environment file. The MQ trigger script
    appends the trigger related environment variables, configured by
    the user, at the end of the file.
    The old content of the gtacl environment file gets not deleted.
    The user application to be started by the MQ trigger script runs
    with these environment variables.
    When an user application, triggered by MQ, shows unexpected
    behaviour that can be related to it's environment variables,
    this should be taken into account as being the root cause.
    

Problem conclusion

  •  The MQ trigger must create an empty gtacl
    environment file.
    In order to prevent the reuse of an existing environment file,
    a timestamp has to be part of the file name.
    

Temporary fix

  •  Check for existing /tmp/gtaclx.PID files where a
    process with that PID does not exist anymore.
    Delete these files.
    

Comments

APAR Information

  • APAR number

    IT28733

  • Reported component name

    WEBS MQ NSS ITA

  • Reported component ID

    5724A3902

  • Reported release

    530

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-04-09

  • Closed date

    2019-06-21

  • Last modified date

    2019-06-21

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    WEBS MQ NSS ITA

  • Fixed component ID

    5724A3902

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCPQ5M","label":"APAR"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.3","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
21 June 2019