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PI71809: MQ - PERFORMANCE IMPROVEMENT WHEN USING C CHANNEL EXITS.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • Performance improvement of the CHIN when using C channel exits.
    

Local fix

  • Add the SCEERUN library to the STEPLIB of the CHIN.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users of IBM MQ for z/OS Version 9 Release 0             *
    * Modification 0.                                              *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * Increased CPU cost when using exits written using the C      *
    * Systems Programming Environment and the CEEEV003 module from *
    * SCEERUN is in the LPA but not the Chinit STEPLIB.            *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When an exit is written using the C Systems Programming
    Environment, each time it is invoked it LOADs the CEEEV003
    module. If this module is in the LPA (as is recommended by IBM),
    then the z/OS LOAD call can take considerably longer to locate
    the module. Since the module is also DELETEd after each
    invocation, the more expensive LOAD operation is repeatedly
    performed. This additional cost may significantly add to the
    overhead of invoking exits.
    

Problem conclusion

  • Processing has been amended to pre-load the CEEEV003 module for
    each MQ dispatcher TCB at startup. This can result in a
    considerable improvement for LOAD times when using SPC exits
    when the CEEEV003 module is located in the LPA.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI71809

  • Reported component name

    MQ Z/OS V9

  • Reported component ID

    5655MQ900

  • Reported release

    000

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-11-04

  • Closed date

    2016-11-30

  • Last modified date

    2017-02-01

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

    PI58641

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

    UI42996

Modules/Macros

  • CSQXDISP
    

Fix information

  • Fixed component name

    MQ Z/OS V9

  • Fixed component ID

    5655MQ900

Applicable component levels

  • R000 PSY UI42996

       UP17/01/10 P F701

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
01 February 2017