PH30768: CICS FEATURE TOGGLE TO REDUCE CPSM WORKLOAD ROUTING TO REMOTE TARGET REGIONS WHEN USING SYSPLEX OPTIMISED WLM

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• CPSM workloads do not favour AORs on the local LPAR when using
  Sysplex Optimised WLM.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSplex SM users.                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Using the QUEUE or GOAL algorithm       *
  *                      for CICSPlex SM sysplex optimised       *
  *                      workload routing results in a           *
  *                      distribution of work spread more        *
  *                      evenly than expected through all        *
  *                      candidate target regions, when it is    *
  *                      expected that target regions on the     *
  *                      same LPAR as the routing region should  *
  *                      be preferred.                           *
  ****************************************************************
  * RECOMMENDATION: After applying the PTF which resolves        *
  *                 APAR PH30768, all MAS regions which          *
  *                 participate in a workload as routing         *
  *                 regions should be restarted to enact         *
  *                 the change.                                  *
  ****************************************************************
  The default behaviour of the CICSPlex SM Workload Management
  routing algorithms have been updated to increase the likelihood
  that work is routed to healthy, local target regions. This
  change applies only to the QUEUE and GOAL algorithms, not to the
  link neutral variants (LNQUEUE and LNGOAL).
  
  
  Where a routing region may be subjected to surges of extremely
  high frequency short duration transactions, workload batching
  may be experienced. A new feature toggle has been introduced to
  mitigate these surges by reducing the likelihood that recently
  selected target regions are reselected. Enabling this feature
  toggle increases the average routing cost per transaction, but
  restores the routing behaviour of CICSPlex SM in CICS TS 5.6,
  prior to APAR PH30768.
  
  Feature toggle value:
  com.ibm.cics.cpsm.wlm.surgeresist={true|false}
                                          -----
  
  When applied to CICSPlex SM WLM routing regions, this
  feature toggle takes effect for the QUEUE and GOAL WLM
  algorithms when using sysplex optimized workload routing.
  It has no effect when applied to target regions. When the
  feature toggle is set to true, surges of extremely high
  frequency short duration transactions can be mitigated by
  reducing the likelihood that recently selected target regions
  are reselected.
  Enabling this feature toggle increases the average routing cost
  per transaction, but restores the routing behaviour of CICSPlex
  SM in CICS TS 5.4 or 5.5 or 5.6, prior to APAR PH30768.
  

Problem conclusion

• The default behaviour of the CICSPlex SM Workload Management
  routing algorithms have been updated to increase the likelihood
  that work is routed to healthy, local target regions. This
  change applies only to the QUEUE and GOAL algorithms, not to the
  link neutral variants (LNQUEUE and LNGOAL).
  
  
  Where a routing region may be subjected to surges of extremely
  high frequency short duration transactions, workload batching
  may be experienced. A new feature toggle has been introduced to
  mitigate these surges by reducing the likelihood that recently
  selected target regions are reselected. Enabling this feature
  toggle increases the average routing cost per transaction, but
  restores the routing behaviour of CICSPlex SM in CICS TS 5.6,
  prior to APAR PH30768.
  
  Feature toggle value:
  com.ibm.cics.cpsm.wlm.surgeresist={true|false}
                                          -----
  
  When applied to CICSPlex SM WLM routing regions, this
  feature toggle takes effect for the QUEUE and GOAL WLM
  algorithms when using sysplex optimized workload routing.
  It has no effect when applied to target regions. When the
  feature toggle is set to true, surges of extremely high
  frequency short duration transactions can be mitigated by
  reducing the likelihood that recently selected target regions
  are reselected.
  Enabling this feature toggle increases the average routing cost
  per transaction, but restores the routing behaviour of CICSPlex
  SM in CICS TS 5.4 or 5.5 or 5.6, prior to APAR PH30768.
  

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:

  UI77845 UI77846 UI77847

Modules/Macros

• CJC0WINT CJC0WNAL CJD0WINT CJD0WNAL CJE0WINT CJE0WNAL CJF0WINT
  CJF0WNAL CJG0WINT CJG0WNAL CJH0WINT CJH0WNAL CJI0WINT CJI0WNAL
  EYU0WINT EYU0WNAL
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R10M PSY UI77847

     UP21/10/30 P F110

• R20M PSY UI77846

     UP21/10/29 P F110

• R30M PSY UI77845

     UP21/10/29 P F110

Fix is available

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