PI61199: U0845 AFTER DFS1769W RC03,RC04 FROM FAILED ATTACH DFS3PBL0. **AE BY PI66013**

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When executing cmds such as /STA DB DFSC* ACCESS=UP, with
  catalog enabled, DFS3PBL0 is called to do an ATTACH of the
  catalog PSB with the users PSB. If the ATTACH is failed in that
  module rc03 or rc04, DFS1769W, then PSTCODE1 is cleared.
  If we have pending buffer updates then later when IMS does
  commit it should purge them but when PSTCODE1 is zero it skips
  purging the buffers.  That leaves us with BQELs unresolved
  which triggers the U0845 later.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All IMS V14 users with IMS catalog enabled.                  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * An application attempting to access the IMS catalog receives *
  * message DFS1769W with RC=04 followed by an ABEND0845.  At    *
  * the same time as the abend a /MODIFY COMMIT online change    *
  * command had been issued and was being processed by IMS.      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  When the IMS catalog is enabled any user PSB can read from the
  IMS catalog using the PCB DFSCAT00.  When this PCB name is
  supplied IMS dynamically modifies the PSB scheduled by the
  dependent region to attach the catalog PCB.  This process is
  known as dynamic attach.  The dynamic attach process is invoked
  when the DL/I call analyzer, module DFSDLA00, determines the
  catalog PCB name has been specified in the AIB.  When DFSDLA00
  detects the catalog PCB name it invokes module DFS3PBL0 to
  attempt dynamic attach.  The dynamic attach can fail for reasons
  similar to normal PSB scheduling such as no PSB pool space or
  OLC change.  When errors occur the message DFS1769W is issued
  and flow returns back to module DFSDLA00.  Upon return from the
  dynamic attach DFSDLA00 traces the request in the SCHD trace
  table and checks the return code from DFS3PBL0.  If the catalog
  PSB could not be attached then code flows to label ACESC200 at
  which point PSTCODE1 is cleared to indicate the catalog PSB
  could not be scheduled.  When PSTCODE1 is cleared and the PSB
  had previously been successfully scheduled the results are
  unpredictable.
  In addition the dynamic attach module DFS3PBL0 is invoked
  when the DL/I call analyzer, module DFSDLA00, determines
  that an INQY DB or INIT STATUSGROUP is being processed in the
  INITACCS routine.   When the PSB cannot be attached a flag is
  set
  in byte PSTCODE1 to indicate the error and DFS1769W is issued
  with flow returning back to module DFSDLA00 to be traced with
  a SCHD trace entry.  The original value in PSTCODE1 should be
  restored after the trace entry is created but it is not.
  If IMS has successfully scheduled a PSB for this PST then the
  results are unpredictable when the PSTCODE1 is not restored.
  
  In either case when database updates have been made then they
  will
  fail to be committed.  This is caused by code in module DFSFXC50
  which checks PSTCODE1 to see if the PSB had ever been scheduled.
  If the PSB had not been scheduled then a shorter code path is
  taken which does not purge buffers because IMS thinks the PSB
  has never been scheduled, and therefore no buffers would need to
  be purged.  In the case of a failed dynamic attach of the
  catalog PSB, the wrong PSTCODE1 flag causes DFSFXC50 to skip
  purging buffers.  When subsequent processing performs database
  integrity checking it will detect there are uncommitted buffers
  and will trigger the ABENDU0845.
  Additional keywords: MSGDFS1769 MSGDFS1769W
  
  GEN:
  POSTREQ PI69656
  

Problem conclusion

• Code has been changed in the following parts.
  
  **********
  * DFSDBA *
  **********
  
  Code has been changed to define a work area to store PSTCODE1
  around the calls to module DFS3PBL0 to dynamically attach the
  catalog PSB.
  
  ************
  * DFSDLA00 *
  ************
  
  Code has been changed to restore the original PSTCODE1
  around the calls to DFS3PBL0 when attempting to
  dynamically attach the catalog PSB.
  

Temporary fix

• The fix for this APAR is BAD.  If you need to apply
  the fix for this APAR to resolve a problem, you must
  also apply the fix for APAR PI66013.
  AE16/07/18
  

Comments

• REPINNED RP16/09/27 (ATXT) TO ADD POSTREQ PI69656 INFO.
   **** PE16/09/27 PTF IN ERROR. SEE APAR PI69656 FOR DESCRIPTION
  ×**** PE16/09/22 FIX IN ERROR. SEE APAR PI69656  FOR DESCRIPTION
  

APAR Information

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

  PI61179

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

  UI39462

Modules/Macros

• DFSDLA00 DFSDBA
  

Fix information

• Fixed component name

  IMS V14

• Fixed component ID

  5635A0500

Applicable component levels

• R400 PSY UI39462

     UP16/07/30 P F607

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.