PM28700: IMS DEDB FAST RECOVERY ENHANCEMENT IN SUPPORT OF IMS V10 APAR PM12762 AND IMS V11 APAR PM13868

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• IMS DEDB Fast Recovery enhancement in support of:
  IMS V10 APAR PM12762 (PTF is UK56940)
  IMS V11 APAR PM13868 (PTF is UK57124)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS DEDB FAST RECOVERY Version 2         *
  *                 Release 2 (FMID=H1J2220) users in IMS V10    *
  *                 or V11.                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: This APAR is DFR version for IMS V10    *
  *                      APAR PM12762 (PTF is UK56940) and IMS   *
  *                      V11 APAR PM13868 (PTF is UK57124).      *
  *                      - PM12762 and PM13868                   *
  *                      During IMS shutdown process ( DEDB area *
  *                      close phase ), CEC failed. For one MADS *
  *                      area, the DMAC in one ADS was updated   *
  *                      but not in the other ADS, due to the    *
  *                      CEC failure.                            *
  *                      DBFCMOC2 updates DMACCUSN and logs      *
  *                      global and local 5957 log records.      *
  *                      Restart applied the DMACCUSN update to  *
  *                      memory DMAC but did not REDO the DMAC   *
  *                      since DMACF6CS was not set in local     *
  *                      x5957 log record.                       *
  *                      If the DMAC that missed the I/O is in   *
  *                      first ADS, then all is still OK since   *
  *                      DMACCUSN is reset from DASD DMACCUSN in *
  *                      DBFMPOP0 during open. However, if it is *
  *                      the 2nd or Nth ADS, then open will fail *
  *                      with message DFS3702 RC18 since memory  *
  *                      DMAC DMACCUSN will not match read-in    *
  *                      DASD DMACCUSN.                          *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  - PM28700 for IMS DEDB Fast Recovery
  If an area that was opened when IMS failed was not in block-
  level data sharing, DFR always recovers DMAC for the area.
  *
  If the area was in block-level data sharing, DFR recovers DMAC
  for the area in following conditions:
   - DMACF6CS bit of DMACFLG6 flag was set in X'5957' log record.
   - A value of DMACCUSN that was reconstructed by IMS log records
     is equal to the value of DASD DMACCUSN plus 1.
  If the area which needs to recover DMAC was closed when IMS
  failed, DFR opens the area forcedly and recovers DMAC for the
  area.
  *
  Although DMACF6CS bit was set only for the area that is in
  block-level data sharing, IMS changed by the APAR of IMS so that
  DMACF6CS bit might be set for area that is not in block-level
  data sharing.
  Since DFR checks DMACF6CS bit on the assumption that the area is
  in block-level data sharing, DFR issues MSGDFR3561E message
  instead of MSGDFR3560E message and recovers DMAC for the area
  that was closed when IMS failed and was not in block-level data
  sharing.
  

Problem conclusion

Temporary fix

Comments

• The following modules have been modified.
  (x = A and B)
  *
  DFRNFCTx - This module was changed so that DFR might bypass the
             forced open process of the area data set when the
             area was not in block-level data sharing.
  *
  DFRNFSTx - This module was changed so that DFR might bypass the
             recovery process of the DMAC when the area was not in
             block-level data sharing.
  *
  

APAR Information

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

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

  UK63176

Modules/Macros

• DFRNFCTA DFRNFCTB DFRNFSTA DFRNFSTB
  

Fix information

• Fixed component name

  DEDB FAST RECOV

• Fixed component ID

  5655E3200

Applicable component levels

• R220 PSY UK63176

     UP10/12/21 P F012

Fix is available

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