PI63812: WITH SYSPLEX OPTIMIZED WORKLOAD, INCORRECT LOAD COUNT USED WHEN TRANSACTION ENDS AND MAS HEARTBEAT OCCURS SIMULTANEOUSLY

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Using a sysplex optimized workload and monitoring the work
  running in the target regions, you noticed using SMF data that
  for some of the targets, there was a period where no
  transactions were started or stopped in that region.  The
  problem seem to occur for about 15 seconds.
  .
  With UPDATERS=5 and MXT=60, MAS CICSA had 9 tasks running (6
  long running tasks and 3 user tasks) for a lower tier boundary
  of 9.  The task count of 9 remained for CICSA even though the 3
  user transactions had ended.  So for each transaction route
  request in the routing region (TOR), CICSA would not be chosen
  as the best target region to route the work to because there
  were other regions with a lower task count available.  And
  since no new task were routed to CICSA, it was not until the
  heartbeat ran at the next 15 second interval in CICSA that its
  task count was changed to 6, allowing it to have "equal
  conditions" to the other MASes and more selectable as the
  target region to route to.
  .
  .
  .
  Additional Symptom(s) Search Keyword(s): KIXREVGJT
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSPlex SM V5R1M0 and V5R2M0 Users      *
  ****************************************************************
  * PROBLEM DESCRIPTION: When using CPSM WLM Sysplex Optimized   *
  *                      processing work may not be routed to a  *
  *                      target region by routing regions for a  *
  *                      period of up to 15 seconds after a task *
  *                      ends in the region.                     *
  ****************************************************************
  * RECOMMENDATION: After applying the PTF that resolves this    *
  *                 APAR, all MASes must be restarted.  Note     *
  *                 that the restarts do not need to occur at    *
  *                 the same time.                               *
  ****************************************************************
  Every 15 seconds in a target region, CPSM heartbeat processing
  occurs.  If the region is running in CPSM WLM Sysplex optimized
  mode, module DFHRSSR (RSSR) is called.  RSSR verifies that the
  region still has a connection to the Region Status (RS) domain
  coupling facility data table (CFDT) server.  If it does still
  have a connection and the last write to the CFDT server was over
  one second before, then RSSR will use the current task count to
  update the RS block for the region.  RSSR first updates the RS
  block copy in the RS domain anchor block.  Then, if no other
  update is occurring at that time by the region, RSSR will issue
  a file control request to update the CFDT server copy of the RS
  block.  Then, regardless of whether or not another update is
  occurring at that time by the region, RSSR updates the WLM data
  space copy of the RS block.
  
  If a task is ending at the same time as heartbeat runs and the
  ending of that task would cause the task count tier value to
  lower, then that lower value could be overlayed by RSSR.  This
  could result in routing regions not having an accurate picture
  of the true task load in the target region.
  

Problem conclusion

• RSSR has been updated so that it will only update the RS domain
  anchor block and the WLM data space copies of the RS block if no
  other CF update is in progress.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PI62720

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

  012AC3Ÿ UI38675 UI38676

Modules/Macros

• DFHRSSR  DFHRSSRT
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R800 PSY UI38675

     UP16/06/17 P F606

• R900 PSY UI38676

     UP16/06/17 P F606

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.