PH63313: CPSM API COMPLEX CRITERIA FILTER EXPRESSION GENERATES AN INCREASE IN RESULT SETS AFTER MIGRATION TO CICS TS 6.1

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A REXX program in batch is using the CPSM API to new copy
  (Phase-in) programs in a CICS MAS region.
  After migrating to CICS TS 6.1, the performance of the batch
  program was degraded because the number of EXEC CICS commands
  being performed by the CPSM agent transaction CONL was
  significantly increased.
  Analysis of the diagnostics provided showed the problem occurs
  due to the complex criteria filter expression containing sub
  filters within brackets.
  
  When the filter string is being processed, due to changes in
  EYU0XDOP, we no longer correctly identify the key value for the
  resource being queried, though one exists in the filter.
  
  When a key value is located, this is used on the CPSM calls to
  the MAS regions, to limit the scope of the records to be
  fetched, rather than getting all records that match the target
  scope.
  
  As such, due to this change of logic in 6.1, and the use of
  brackets in the filter expression, it resulted in the increase
  of result sets causing the performance degradation in the batch
  job.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSPlex SM Users.                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Increased CPU usage may be seen when    *
  *                      using the CPSM API to perform an        *
  *                      operation when providing a criteria     *
  *                      containing the expression in            *
  *                      brackets/parenthesis, when compared to  *
  *                      releases earlier than 6.1.              *
  ****************************************************************
  * RECOMMENDATION: After applying the PTFs addressing this      *
  *                 APAR, all CMAS regions should be restarted.  *
  *                 Restarts may be performed in any order.      *
  ****************************************************************
  When a filter expression is passed into a CICSPlex SM API
  request in the CRITERIA field, the CMAS attempts to identify
  and extract key fields for the requested resource from the
  expression, such as resource name.
  This allows the CMAS to generate requests to the LMAS regions
  within the scope of the request that contain this field value,
  to reduce the number of results returned on internal
  EXEC CICS INQUIRE requests, and further processing for the
  filter expression.
  
  However, when a filter expression is contained within
  brackets, the key is not correctly extracted from filter when
  it could be identified. This results in the subsequent requests
  performed by the LMAS regions not passing the key value. This
  results in the LMAS regions initially building larger result
  sets than intended, which are then filtered according to the
  CRITERIA expression. The intended result set is produced,
  albeit with higher processing costs.
  This results in an increase in CPU when comparing to
  releases prior to 6.1 for the same request.
  

Problem conclusion

• Filter expression processing has been corrected to extract the
  key values from the filter and pass this to the subsequent
  internal resource requests, to reduce the CPU usage of the
  processing when applicable.
  

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:

  UI98742 UI98743

Modules/Macros

• EYU0XDOP
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R40M PSY UI98743

     UP24/10/17 P F410

• R50M PSY UI98742

     UP24/10/17 P F410

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.