PM61982: LOCKS NOT BEING HELD AFTER DYNAMIC BACKOUT FAILURE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Following situation. Database is PHIDAM with an SI based on some
  part of the root segment. The SI is defined in RECON as
  non-recoverable. A BMP is started on IMN2 which deletes some
  root segments (leads to deletes in the SI) and then is halted
  by a WTOR. Multiple log swicthes are now forced with SWI OLDS
  until the message 'SLDS required  for  backout' is issued. Now
  the BMP is abended using STO REG ABDUMP.
  The  first of the deleted root segments is backouted but the
  attempt to backout the corresponding update to the SI fails
  because the necessary records are not available on the SLDS
  (non-recoverable !).
  Dynamic backout fails and the database now has status STOPPED,
  BACKOUT and  Backout Needed is on in RECON. Any attempt to
  start a further BMP against this partition on IMN2 abends U3303
  because of the status STOPPED, BACKOUT. Any attempt to start
  the partition fails   becuase it causes a retry of the dynamic
  backout and that, of course, fails for the same reason as
  originally.
  So far so good. However, if a read BMP is now started on IMN1
  using PROCOPT=A it is possible to read all root segments from
  the beginning to the end of the partition ! This should not be
  possible since IRLM  locks should still exist for some blocks
  as a result of the failed Dynamic Backout.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS V11 users who data share and update  *
  *                 High Availability Large Databases, HALDBs.   *
  ****************************************************************
  * PROBLEM DESCRIPTION: After a backout failure on one IMS, a   *
  *                      partition can still be accessed with a  *
  *                      PROCOPT=A PCB on a sharing IMS. This    *
  *                      should not be allowed.                  *
  ****************************************************************
  * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF      *
  ****************************************************************
  User has a PHIDAM database that has a dependent segment under a
  root that is indexed via a PSINDEX database.  The PSINDEX
  database is defined as non-recoverable in the RECON.  The
  databases are globally shared; e.g. data shared.
  Two IMS systems are sharing the databases when a BMP is run
  on one IMS that deletes several root segments which result
  in updates to the PSINDEX. The BMP does not terminate and
  goes into a wait state. Multiple log switches occur. A display
  of the OLDS shows:
  DFS000I      SLDS REQUIRED FOR BACKOUT - RGN 00001, SLDSREAD ON.
  
  The BMP is then terminated with a /STOP REGION 1 ABDUMP command.
  During ABDUMP processing the following messages are received:
  DFS987I ERROR READING SLDS DURING BACKOUT WITHIN PSB=PSBNAME
  DUE TO NON-RECOVERABLE DB IMSID
  DFS979I BATCH MESSAGE PROGRAM PSBNAME WAS ACTIVE AT TIME OF
  FAILURE IMSID
  DFS975W  NON-RECOVERABLE DBD=PSINDEX  WITHIN PSB=PSBNAME STOPPED
  DUE TO UNKNOWN BACKOUT STATUS IMSID
  DFS981I  DBD=PARTNAM1 WITHIN PSB=PSBNAME STOPPED DUE TO BACKOUT
  FAILURE IMSID
  DFS981I  DBD=PARTNAM2 WITHIN PSB=PSBNAME STOPPED DUE TO BACKOUT
  FAILURE IMSID
  DFS980I 16:45:17 BACKOUT PROCESSING HAS ENDED FOR PSBNAME IMSID
  
  On this IMS a display of the related partitions show a status
  of: STOPPED, BACKOUT, ALLOCS
  
  Any attempt to access the stopped partitions, on this IMS,
  results in the following messages and an ABENDU3303.
  DFS3303I PSB PSBNAME  PCB DBDNAME DBD PARTNAME PARTUNAV  JOBNAME
  JOBNAME  RGN 00001 IMSID
  DFS0832I ABEND U3303 REASON CODE 4020 PARTITION PARTNAME IMSID
  
  A /START DB for the stopped partitions fails because dynamic
  backout is part of the command processing and it fails for the
  same reasons as previously described.
  
  The above is all correct processing. The problem is a PROCOPT=A
  BMP is allowed to access a stopped partition on the sharing IMS
  when the partition should not be available. All locks were
  released at the end of the STOP REGION ABDUMP processing and
  database (partition) integrity should be protected by flagging
  the partition as stopped and in error.
  A display of the stopped partitions on the sharing IMS do not
  show STOPPED, only ALLOCS.
  A RECON listing shows BACKOUT NEEDED =ON for the partitions that
  are marked as recoverable. The non-recoverable PSINDEX shows
  BACKOUT NEEDED =OFF.
  
  Missing notifies are the reason the recoverable partitions are
  not flagged as stopped, DDIRNOSC, and in error, DDIRDBIE.
  
  DFSRBOI0 is called by DFSFXC50 during /STOP REGION ABDUMP
  processing to do dynamic backout.  Part of the backout failure
  processing is to notify all sharing subsystems that the
  databases, partitions in this case, are in error and should be
  stopped.  The sending of the notifies were skipped because flag
  DDIRGLCK was not on in the recoverable partition DDIRs.
  DDIRGLCK should be set on during authorization of the partitions
  but code in DFSDBAU0 after label ALOOP2 checked for partitioned
  databases and bypassed the code that set the global locking
  required flag, DDIRGLCK.
  
  Additional Keywords: MSGDFS3303I STACMD CMDSTA MSGDFS0832I
                       MSGDFS000I MSGDFS987I MSGDFS979I MSGDFS975W
                       MSGDFS981I MSGDFS980I STOCMD CMDSTO REG
  

Problem conclusion

• GEN:
  POSTREQ PM73440
  KEYWORDS:
  
  *** END IMS KEYWORDS ***
  Code has been added to the partition authorization routine,
  OLICCALL, in DFSDBAU0 after label DSGSDONE to set DDIRGLCK
  when the lock scope flags indicate global locking.
  

Temporary fix

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

Comments

• REPINNED RP12/09/21 (ATXT) TO ADD POSTREQ PM73440 INFO.
   **** PE12/09/21 PTF IN ERROR. SEE APAR PM73440 FOR DESCRIPTION
  ×**** PE12/09/21 FIX IN ERROR. SEE APAR PM73440  FOR DESCRIPTION
  

APAR Information

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

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

  PM64598 UK79837

Modules/Macros

• DFSDBAU0
  

Fix information

• Fixed component name

  IMS V11

• Fixed component ID

  5635A0200

Applicable component levels

• R100 PSY UK79837

     UP12/07/03 P F207 Ž

Fix is available

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