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PI84838: WLM CLASSIFICATION OF IMS TRANSACTION BY IMS TRANSACTION CLASS NOT ALWAYS CONSIDERED 17/07/24 PTF PECHANGE

A fix is available

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APAR status

  • Closed as program error.

Error description

  • Observing incorrect assignment of WLM Service and Report Classes
    based on IMS Transaction Classes.
    -
    Over 50% of all IMS Transactions covered by IMS Default Service
    and Report Class instead of the current configured
    Classification policy defined by WLM.
    

Local fix

  • no
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users of IMS v14                                         *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * 1.  WLM service classes for IMS transactions may be assigned *
    * incorrectly.                                                 *
    * 2.  Incorrect data in 56FA log record due to overlay of      *
    * DFSTLS block.IN                                              *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
    ****************************************************************
    Two issues are addressed in this apar.
    1.   In DFSYTIB0, the service class may be reported incorrectly
    to WLM.  This occurs because the expansion of the DFSWLMY macro
    uses R13 as a base register for SMBCLASS_PTR, even though, at
    this point in the code, R13 is being used to point to a save
    area to be used by WLM.
    
    2.  An incorrect length is used for the DFSTLS block.  In some
    cases, a length of 218x is used instead of the correct length of
    260x.  APAR pi51948 increased the length of the block from 218x
    to 260x.  This results in an overlay of the section of DFSTLS
    beyond offset 218x.  Because this is the section added by
    pi51948, used to store processor usage data, this can cause
    incorrect processor usage data to be written to the 56FA log
    record and/or reported to WLM on the DFSWLMN service call.
    

Problem conclusion

  • 1.  In APAR pi51948, we needed to change the handling of save
    areas in DFSYTIB0 to account for the fact that the 64 bit
    version of the WLM Classify service (IWM4CLSY) expects r13 to
    point to a 216-byte save area.  This was accomplished by
    temporarily copying the dynamic storage address in r13 to r9
    across the DFSWLMY call, and having r13 point to the 216 byte
    save area.  The problem this introduces is that the compiler
    used r13 as a base register for SMBCLASS_PTR in the DFSWLMY
    macro expansion, when r13 is no longer pointing to the dynamic
    storage area.
    
    This is fixed by adding a USING statement in gen code to tell
    the assembler that R9, not R13, contains the address of the
    dynamic storage area during the DFSWLMY call.
    
    2.  The DFSTLS length is incorrect because some modules that
    reference TLSLEN were not recompiled in pi51948.  Those modules
    are recompiled by this APAR.  They are:
    DFSCDMP0
    DFSDTTA0
    DFSSDA30
    DFSMINI0
    DFSPSTB0
    DFSTMAS0
    DFSSDA20
    DFSABND0
    DFSFDMP0
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI84838

  • Reported component name

    IMS V14

  • Reported component ID

    5635A0500

  • Reported release

    402

  • Status

    CLOSED PER

  • PE

    YesPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-07-24

  • Closed date

    2017-08-17

  • Last modified date

    2017-09-02

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

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

    PI84889 UI49649

Modules/Macros

  • DFSYTIB0 DFSABND0 DFSPSTB0 DFSSDA20 DFSSDA30 DFSCDMP0 DFSMINI0
    DFSTMAS0 DFSDTTA0 DFSFDMP0
    

Fix information

  • Fixed component name

    IMS V14

  • Fixed component ID

    5635A0500

Applicable component levels

  • R400 PSY UI49649

       UP17/09/01 P F708 {

Fix is available

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Document Information

Modified date:
12 June 2020