PK75605: ABEND0C4 IN IMS'S DFSIDSP0 AFTER LABEL DFSIPOST NEAR X'1936'

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• IMS control region ABENDS0C4 DFSIDSP0 with QCF active.
  The abend occurs when we try to post a task and the ECB
  no longer exists as the storage was reused.
  
  Additional issue fixed:
  After a QCF LOAD job, loading previously unloaded messages
  back on the queue, leaves garbage on the queue after it ends
  RC16 due to the FAILSAFE setting (it gets stopped because it
  wants to fill the queue beyond the specified threshold).
  The messages cannot be seen on the queue with the regular IMS
  display commands or a QCF Query via the panels, however
  QCF Query, the number of messages can be seen when displaying
  the status of the local queue. A normal restart of IMS cleans
  the messages/queue usage.
  

Local fix

• Disable Overflow Protection (QSN) or QCF as follows:
  1) To disable QSN and use default QCF V2.1 table protection:
     Remove all AREA and FAILSAFE cards from IMS start up member
     and leave only whatever is left.  It may look something like:
     IMSPLEX(IMSAP)
     ONABEND(DUMP)
     ONINITERR(TERM)
     TRACEPAGES(16)
  2) To disable QCF:
     Remove the partner exit for QCF V3.1 from member GPRimsid0
     and GPREXIT0. These should be in the IMS proclib and are
     used to initialize QCF V3.1 in the control region.
       GPRimsi0 - defines exits for specific IMS
       GPREXIT0 - defines exits for all IMSs
     Also, be sure that DFSPPUE0 is not in the QCF start up
     library.  When the IMS control region starts, the following
     message should no longer appear:
     IQC6001I QCF IMS EXTENSIONS ENABLED
     When this message doesn't show at IMS startup, that confirms
     QCF is disabled.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of QCF3.1.                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: IMS hangs or control region abends      *
  *                      with 0C4 in DFSIDSP0- these different   *
  *                      situations are caused by invalid ECBs   *
  *                      posts when the load of the queue is     *
  *                      heavy.                                  *
  *                      If QCF3.1 LOAD JOB is abended or        *
  *                      stopped, no rollback is done and the    *
  *                      messages continue to fill up the        *
  *                      queue buffers without to show.          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  IMS control region ABENDS0C4 DFSIDSP0 and IMS hang with
  QCF active are  fixed in source IQCCQATX. Wait/post is
  done with IQC identifier and the correct ECBs are posted.
  
  After a QCF LOAD function is abended/stopped by QSUN -
  return code of 44 is set and rollback takes place. The
  rollback will free the queue buffers and they can be reused.
  Usage of queue show correct - there are no occupied blocks
  with no messages to show.
  

Problem conclusion

• Install the APAR to avid control region hangs and 0C4 abends.
  

Temporary fix

Comments

APAR Information

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

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

  UK43322

Modules/Macros

• IQCBTQCF IQCCCVCA IQCCCVCB IQCCCVCX IQCCCVC8
  IQCCCVC9 IQCCQATA IQCCQATB IQCCQATX IQCCQAT8 IQCCQAT9 IQCLOD61
  IQCXCTRL
  

Fix information

• Fixed component name

  IMS QUEUE CNTL

• Fixed component ID

  5697E9900

Applicable component levels

• R310 PSY UK43322

     UP09/01/21 P F901 Ž

Fix is available

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