OA47985: XCF MESSAGE ISOLATION ISSUES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The following XCF MESSAGE ISOLATION issues need to be addressed:
  - Extra spaces appear in messages MSGIXC637I and MSGIXC638I
    - MSGIXC637I is not issued in a timely manner when documenting
      the closure of an isolation window
    - MSGIXC440E is not DOM'd in a timely manner after all
      isolation windows have closed
    - Add an XCF FUNCTIONS switch to enable disablement of
      the MESSAGE ISOLATION function
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of z/OS V2R2 (HBB77A0).            *
  *                                                              *
  *                 There is a SYSPLEXDS impact.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: Provides fixes and updates for XCF      *
  *                      message isolation processing            *
  *                      -MSGIXC637I alignment problems          *
  *                      -MSGIXC638I alignment problems          *
  *                      -MSGIXC637I needs to be more timely     *
  *                      -MSGIXC440E needs more timely DOM       *
  *                      -FUNCTIONS switch to disable            *
  *                      -IXCMG impact counts always zero        *
  ****************************************************************
  * RECOMMENDATION: Install PTF via rolling IPL.                 *
  ****************************************************************
  Fixes and updates needed for XCF Message Isolation processing.
  

Problem conclusion

• Fixed spacing problems in MSGIXC637I and MSGIXC638I.
  
  Revised processing so that MSGIXC637I is issued in a more
  timely manner to document the close of an "impact window".
  In general it should now be the case that MSGIXC637I is
  issued at the start and end of each impact window.  Prior
  to this fix, the close of an impact window might not be
  documented by an instance of MSGIXC637I until the window had
  been closed for up to 10 minutes.
  
  In conjunction with the above change, the DOM'ing of
  MSGIXC440E to indicate that no local members are being impacted
  by message isolation will occur in a more timely fashion as
  well.  Prior to this change, the message might not have been
  DOM'ed for several minutes after the point at which the
  system recognized that there were no impacted members.
  
  A new SETXCF functions switch MSGISO provides installation
  control over XCF message isolation processing.  The switch
  is enabled by default.  If the switch is disabled, XCF group
  members that might be impeding the flow of signals in the
  sysplex will not be message isolated.  The switch can be
  set with either the COUPLExx parmlib member FUNCTIONS
  statement or the SETXCF FUNCTIONS operator command.
  
  Fixed the XCF measurement gathering service (IXCMG) so that
  valid counts would be returned for the following fields
  defined in the IXCYAMDA macro:
   - AMDMEM_MsgoDelayedForMISO
   - AMDMEM_MsgoRejectedForMISO
  
  +--- PUBLICATIONS AFFECTED ------------------------------------+
  |                                                              |
  | o   z/OS MVS Setting Up a Sysplex,                           |
  |     SA23-1399-xx                                             |
  | o   z/OS MVS System Messages, Vol 10 (IXC-IZP)               |
  |     SA38-0677-xx                                             |
  |                                                              |
  +--------------------------------------------------------------+
  
  In z/OS MVS Setting Up a Sysplex, the MSGISO function is
  added to "Table 1. XCF/XES Optional Functions" described
  in "The FUNCTIONS statement" section:
  ...
   Name       Function                               Default State
   ---------  -------------------------------------  -------------
  ...
  |MSGISO     XCF Message Isolation.  When this      Enabled
  |           function is disabled, the system will
  |           no longer isolate a member when it
  |           fails to make adequate progress with
  |           respect to the processing of its
  |           messages.  Message isolation helps
  |           keep problematic group members from
  |           impeding the delivery of messages to
  |           other members. While a member is
  |           isolated, XCF delays or rejects
  |           messages targeted to that member.
  |           Enabling message isolation enhances
  |           XCF's ability to protect the sysplex
  |           from problematic group members.
  
  In z/OS MVS System Messages, Vol 10 (IXC-IZP):
  
  - IXC357I message explanation is updated to include MSGISO in
    the list of XCF/XES optional function names:
      ...
      OPTIONAL FUNCTION STATUS:
         FUNCTION NAME      STATUS              DEFAULT
         funname            {ENABLED|DISABLED}  {ENABLED|DISABLED}
      ...
    funname
    Name of XCF/XES optional function. See z/OS MVS Setting Up a
    Sysplex for descriptions of the listed function names. funname
    is one of the following values:
    ...
    ...
          DUPLEXCF16
    ...
  |       MSGISO
    ...
  
  - IXC373I message explanation is updated to include MSGISO in
    the list of XCF/XES optional function names:
      ...
      function
          The optional XES/XCF functions:
  
        o DUPLEXCF16
      ...
  |     o MSGISO
      ...
  
  - IXC638I message explanation is updated to indicate that
    an isolation window can be closed as the result of the MSGISO
    function being disabled.
      ...
    The isolation window closed because member member_name appears
    to be making adequate progress with respect to the processing
  | of its messages, or because the XCF functions MSGISO switch
  | was set to DISABLED.  The member is no longer message
    isolated.
  

Temporary fix

Comments

APAR Information

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

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

  UA78474

Modules/Macros

• IXCA1MG  IXCA1TSK IXCF1INT IXCI1RLF IXCI1RS
  IXCI2RIM IXCM2FMS IXCM2FNP IXCM2LX2 IXCM2MST IXCM2MS2 IXCM2MS3
  IXCM2PRS IXCS1DCM IXCT1MES IXCYAMDA
  

Fix information

• Fixed component name

  XCF

• Fixed component ID

  5752SCXCF

Applicable component levels

• R7A0 PSY UA78474

     UP15/08/19 P F508

Fix is available

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