PH61633: ABEND04E RC00C90207 DSNIOW ERQUAL5003 24/06/19 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Data sharing group is v12/v13 co-existence,
  RPN object may still use old P-lock hash algorithm while the new
  
  page P-lock hash algorithm was enabled on v12, this will cause
  space map page regression, then will finally cause different
  abend like -
  ABEND04E 00C90207 DSNIOW   5003 ERQUAL5003
  ABEND04E 00C90101 DSNKDLE  500A ERQUAL500A
  ABEND04E 00C90101 DSNIBHRE 5007 ERQUAL5007
  ABEND04E 00C90101 DSNIBHUN 5020 ERQUAL5020
  ABEND04E 00C90101 DSNIBHRE 0C26 ERQUAL0C26
  ABEND04E 00C90205 DSNIONX2 504E ERQUAL504E
  ABEND04E 00C90101 DSNKINSL 5033 ERQUAL5033
  

Local fix

• If in Data Sharing and using PBR RPN tablespaces, do not migrate
  
  from V12 to V13R1M100 or activate a higher function level that
  M100 in V13.
  
  If Data Sharing and using PBR RPN tablespaces and if the
  data-sharing group was in Db2 12 before migrating to V13 or in
  Db2 12 and 13 coexistence, or in Db2 13 before activating
  V13R1M500 or above then REORG PBR RPN tablespaces either at
  tablespace level or at partition level.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Db2 12 for z/OS and Db2 13 for z/OS      *
  *                 users of Partition-By-Range (PBR) Relative   *
  *                 Page Numbering (RPN) table spaces and        *
  *                 indexes in data sharing with PH54949         *
  *                 (UI92688 or UI92689) applied.                *
  ****************************************************************
  * PROBLEM DESCRIPTION: ABEND04E RC00C90207 ERQUAL5003 in       *
  *                      DSNIOW,                                 *
  *                      ABEND04E RC00C90205 ERQUAL504E in       *
  *                      DSNIONX2, and                           *
  *                      ABEND04E RC00C90101 in various CSECTs   *
  *                      with PH54949 (UI92688 or UI92689)       *
  *                      applied. The dump title may contain     *
  *                      DSNI* or DSNK* CSECT names.             *
  *                                                              *
  *                      Page regression and undetected data     *
  *                      loss due to different page P-lock       *
  *                      hash algorithms used on different       *
  *                      members of a data sharing group for     *
  *                      the same pageset.                       *
  ****************************************************************
  * RECOMMENDATION: Apply corrective PTF when available          *
  ****************************************************************
  
  With APAR PH54949 (UI92688 or UI92689) applied, PBR RPN table
  spaces and indexes in Db2 12 for z/OS and Db2 13 for z/OS with
  function level 100 (V13R1M100) can take advantage of a new
  hash algorithm to reduce false page P-lock contention in data
  sharing.
  
  However this change can mistakenly cause the new lock algorithm
  to be used in V12 but the old algorithm to be used by a member
  migrated to V13R1M100. On the other hand, it is possible that
  the old algorithm is used by a member in V13R1M100 but another
  member uses the new algorithm once V13R1M500 or above is
  activated. The simultaneous use of different locking algorithms
  on different members of a data sharing group for the same
  pageset can result in page regression, undetected data loss
  and/or Db2 transaction abends in various CSECTs.
  

Problem conclusion

• Db2 code has been modified to remove the changes introduced by
  APAR PH54949 (UI92688 or UI92689) to ensure all Db2 members
  use the same page P-lock hash algorithm so as to avoid above
  issues.
  
  The fix can be applied on one member at a time.
  After applying the fix to all members:
  
  If the data-sharing group was in Db2 12 before migrating to V13,
  or in Db2 12 and 13 coexistence, or in Db2 13 before activating
  V13R1M500 or above,
  then users must run the REORG TABLESPACE utility to disable
  the PBR RPN hash algorithm enhancement of APAR PH54949 prior to
  migrating to V13 or prior to activating V13R1M500 or above.
  The REORG utility can be run at the partition level with
  SHRLEVEL REFERENCE or CHANGE as long as all partitions of the
  PBR RPN table spaces are eventually reorganized. Then after
  activating V13R1M500 or higher, a subsequent REORG TABLESPACE
  can be run to enable the new PBR RPN hash algorithm to reduce
  false page P-lock contention, which can also be accomplished
  by running partition level REORGs as above.
  
  If the data sharing group has been activated for V13R1M500 or
  above, then no further action is necessary after applying the
  fix for PH61633 to all members. A subsequent REORG of PBR RPN
  partitions may be necessary to enable the new hash algorithm
  if a REORG of the partition was not already performed after
  activation of V13R1M500 or above.
  

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:

  UI97574 UI97575

Modules/Macros

• DSNB1OPP DSNB1PMI DSNIFOD  DSNIFOI
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI97574

     UP24/07/11 P F407 ­

• RD10 PSY UI97575

     UP24/07/11 P F407 ­

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.