PI93058: HSSP BMP GETS U3310 ABEND ON UOW LOCK FOR READ-AHEAD UOW, AFTER FP PHASE 2 COMPLETE BUT BEFORE X'41' CHECKPOINT RECORD WRITTEN

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Customer is using LOCKTIME, with status option for BMP.
  DEDB HSSP BMP unexpectedly abends U3310 during a CHKPT, after
  FP Phase 2 is complete ( 5937 logged ) but before 41 record
  for symbolic checkpoint logged. The U3310 is due to a timeout
  waiting for UOW Lock exclusive on next UOW ( read-ahead ), the
  first UOW is locked EXCL. This can be determined from SMF 79.15
  records and 6706 ATRM record snap of EPST. After FP Phase 2
  is logically complete, DBFSYN20 calls DBFSDEQ0 which calls
  DBFUHAR0 to do HSSP read-ahead. The lock request times out
  because another region has a SHR UOW lock on the target UOW.
  This sets up a U3310 in PSTABTRM. On a normal DL/I call, the
  call handler would check the status option and change this to
  a 'BD' status code. But here, control returns to DFSFXC30,
  which finds PSTABTRM set, and issues the U3310. Customer tries
  to restart BMP with CHKP=LAST, which is a problem since FP
  Phase 2 finished and this checkpoint is *before* these committed
  updates, so application appears to encounter duplicate data.
  The issue here is FP Phase 2 didn't really fail, only the
  read-ahead for next HSSP UOW timed out.
  DBFUHAR0, when called as part of syncpoint, should not leave
  an abend code set in PSTABTRM for any lock issues ( not just
  lock time ), but just exit. The application can find out about
  the lock problem, if it still exists, on first DL/I call after
  checkpoint, where it will be handled properly.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: IMS V13 FP HSSP Users                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: HSSP BMP GETS U3310 ABEND ON UOW LOCK   *
  *                      FOR READ-AHEAD UOW, AFTER               *
  *                      FP PHASE 2 COMPLETE BUT BEFORE X'41'    *
  *                      CHECKPOINT RECORD WRITTEN               *
  ****************************************************************
  * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF      *
  ****************************************************************
  HSSP BMP GETS U3310 ABEND ON UOW LOCK FOR READ-AHEAD UOW, AFTER
  FP PHASE 2 COMPLETE BUT BEFORE X'41' CHECKPOINT RECORD WRITTEN
  

Problem conclusion

• GEN:
  KEYWORDS:
  
  *** END IMS KEYWORDS ***
  DBFEPST
  
  Added new bit EPSTSDEQ to show DBFSDEQ0 is calling DBFUHAR0
  
  DBFSDEQ0
  
  Turn on EPSTSDEQ to tell DBFUHAR0 that DBFSDEQ0 is calling
  
  DBFUHAR0
  
  When Lock request to read UOW fails, clear PSTABTRM when caller
  is DBFSDEQ0
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

  PI93005

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

  UI56155

Modules/Macros

•    DBFEPST  DBFSDEQ0 DBFUHAR0
  

Fix information

• Fixed component name

  IMS V13

• Fixed component ID

  5635A0400

Applicable component levels

• R300 PSY UI56155

     UP18/06/01 P F805 Ž

Fix is available

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