PI06377: CPSM FEPI CPU PERFORMANCE OVERHEAD AFTER MIGRATION TO CICS TS 5.1

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After migrating from CICS version 3.1 to 5.1, a significant CPU
  uplift was noticed. The change team have managed to recreate and
  have found the overhead is in the CPSM issuing all of the FEPI
  API requests unnecessarily.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSPlex SM V5R1M0 Users                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: When upgrading from a CPSM release      *
  *                      prior to V4R2M0, if FEPI connections    *
  *                      are installed in a MAS, an increase in  *
  *                      CPU usage may be noticed due to the MAS *
  *                      inquiring on all FEPI connections every *
  *                      30 seconds under the COIE heartbeat     *
  *                      task.                                   *
  ****************************************************************
  * 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.                               *
  ****************************************************************
  The CPSM Topology component maintains lists for most CICS
  resources, including FEPI connections, so that when requests are
  made to access these resources, CPSM knows which MASes to direct
  the requests to.  In order to build and maintain these lists,
  CPSM utilizes the CICS XRSINDI global user exit (GLUE), to be
  informed of dynamic installs and discards.  For CICS resources
  not supported by the XRSINDI GLUE, for example, transaction dump
  codes, CPSM inquires on the resources every 30 seconds under the
  COIE heartbeat task.
  
  A change was made during development of CPSM V4R2M0 to update
  method EYU0NLT2 (NLT2) to include FEPI connections in the
  inquires performed by the COIE heartbeat task.  Since FEPI
  connections are supported by the XRSINDI GLUE, this is not
  required and results in unnecessary CPU overhead when FEPI
  connections are installed in a MAS.
  

Problem conclusion

• EYU0NLT2 has been updated to not inquire on FEPI connections
  when being called under the COIE heartbeat task.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PI06363

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

  UI12735

Modules/Macros

• EYU0NLT2
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R80M PSY UI12735

     UP13/12/02 P F311

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.