OA52291: EXTRANEOUS PURGE OF IRRACEE FROM A FAILED COFCREAT.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Externally, it is possible to notice (in VLF SMFtype41 records)
  that a Purge has occurred to the IRRACEE VLF Class as the rate
  of finds drops and the rate of writes increases for a duration.
  It is more noticeable when using KDFAES and very heavy workloads
  with common/shared userids.
  
  ANALYSIS:
  During a VERIFY, RACF's ICHRIN00 can call IRRACM00 to stash an
  ACEE oject to VLF.  If the COFCREAT fails (RC10) due to the VLF
  UToken being associated with a different ASID, it will do a
  COFIDENT to get a new VLF Utoken for "this" ASID.  If we are in
  a race condition, another ASID could also do a COFIDENT right
  after us.  As RACF only saves one UToken on the system and does
  not serialize this process, the 2nd COFCREAT from "this" ASID
  will also fail - ex. RC2 RSN4 (but it could be another RC10).
  
  KNOWN IMPACT:
  IRRACM00 treats these 2nd failures as "unknown" problems with
  VLF and sets a flag to Purge all ACEEs from VLF during the next
  attempt to stash one.
  This can cause a major performance impact to high-workload
  environments.
  
  VERIFICATION STEPS:
  VLF Ctrace would need to be on, and a SLIP set at the beginning
  of COFPURG code.
  
  ADDITIONAL SYMPTOMS:
  KDFAES CPU
  

Local fix

• BYPASS/CIRCUMVENTION:
  Reduce the amount of unique logins.
  
  RECOVERY ACTION:
  There is nothing to do but watch RACF re-build the ACEE cache
  over time.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * RACF installations that have activated                       *
  * the IRRACEE VLF class to cache RACF                          *
  * objects (i.e. RACF ENVR objects).                            *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * The RACF code that performs the caching of the RACF objects  *
  * (i.e. RACF ENVR objects) in the IRRACEE VLF class does not   *
  * handle some of the Return Codes from VLF appropriately.      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The RACF code that performs the caching of the RACF objects
  (i.e. RACF ENVR objects) in the IRRACEE VLF class does not
  handle some of the Return Codes from VLF appropriately.
  

Problem conclusion

• The RACF code that performs the caching of the RACF objects
  (i.e. RACF ENVR objects) in the IRRACEE VLF class has been
  modified to handle the Return Codes from VLF appropriately.
  

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:

  UA91754 UA91784 UA91785

Modules/Macros

• IRRACM00
  

Fix information

• Fixed component name

  RACF

• Fixed component ID

  5752XXH00

Applicable component levels

• R790 PSY UA91785

     17/05/25 P F705

• R7A0 PSY UA91784

     17/05/25 P F705

• R7B0 PSY UA91754

     UP17/05/24 P F705

Fix is available

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