PI87291: IMS U0851 ABEND ON ISRT OF PHIDAM ROOT SEGMENT

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• IMS u0851 abends are sporadically seen on ISRT of root segment
  into HALDB PHIDAM database.  This problem is seen when a
  backout (back-out, ROLB, ROLS) is being done against a PSB,
  PHIDAM primary index in particular,  when same PSB is being
  copied for parallel scheduled  transaction/PSB.  During backout
  of PHIDAM index, the x40 bit of DSGINDA is being turned off and
  when PSB is being copied, DSGINDA x40 (DSGDSORI) is not being
  turned back on.  When new transaction/PST does root segment
  ISRT into same PHIDAM DB, u851 will occur.  Leading up to ISRT,
  IMS calls buffer handler (PSTSTLEQ) to get root with key >= key
  being inserted and the buffer handler sets PSTDATA to point at
  root segment satisfying this.  When DSGINDA x40 is not turned
  back on, PSTDATA following this call stills points into index
  buffer, causing the abend on return to DFSDLR00 (2nd pass).
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All IMS V14 PHIDAM HALDB users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ABENDU0851 occurs on an insert call to a root segment of a   *
  * HALDB PHIDAM database while another dependent region is      *
  * issuing a ROLB call against the same PHIDAM database.        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  A U0851 abends are sporadically seen on ISRT of root segment
  into HALDB PHIDAM database.  This problem occurs when a backout
  ( ROLB or ROLS ) call is being processed against a PHIDAM
  primary index while the same PSB is being copied for parallel
  scheduled.  During backout of the PHIDAM index, the x40 bit (
  DSGDSORI ) of DSGINDA is being turned off while the PSB is being
  copied, When the PST does a ISRT into the same PHIDAM root
  segment a U0851 will occur.  Leading up to ISRT, IMS calls
  buffer handler ( PSTSTLEQ ) to get root with key >= key being
  inserted and the buffer handler sets PSTDATA to point at root
  segment satisfying this condition.  When flag DSGDSORI is not
  turned back on, PSTDATA still points into the index buffer
  causing the abend on return to DFSDLR00.
  

Problem conclusion

• ************
  * DFSDBLP0 *
  ************
  
  Code is added in module DFSDBLP0 after label CHCKNDX to set
  DSGDSORI when an index database is detected.
  

Temporary fix

• *********
  * Hiper *
  *********
  

Comments

APAR Information

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

  PI86998

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

  PI89415 UI51751

Modules/Macros

• DFSDBLP0
  

Fix information

• Fixed component name

  IMS V14

• Fixed component ID

  5635A0500

Applicable component levels

• R400 PSY UI51751

     UP17/11/16 P F711 ¢

Fix is available

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