PK51219: RECUPERATE CQS FROM MSGCQS0350W

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• MVS Logger ran out of DASD space and could not allocate an
  offload dataset for the shared queues log stream, as message:
  IXG301I SYSTEM LOGGER FAILED TO OFFLOAD DATA FOR LOG STREAM.
  .
  And CQS address space got message:
  CQS0350W CQS LOG CONNECT PREVIOUS OFFLOAD ERROR LOG STREAM xxx
  CQS0350W CQS LOG WRITE PREVIOUS OFFLOAD ERROR LOG STREAM xxx.
  .
  Customer made some DASD space available to MVS logger. but
  the logstream remained stuck.
  .
  To resolve the problem, customer has to recycle CQS (and IMS),
  which is not very acceptable in a 24/7 production IMS.
  They are looking for a less disruptive method to gracefully
  recover from thissituation.
  

Local fix

• Recycling the CQS adress space solved the problem.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS V10 shared queues users and shared   *
  *                 EMH users, and all CQS users.                *
  ****************************************************************
  * PROBLEM DESCRIPTION: CQS initiates a Structure Checkpoint    *
  *                      for every IXGWRITE with RC=04 and       *
  *                      RSN=0409.                               *
  ****************************************************************
  * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF      *
  ****************************************************************
    CQS relies on MVS logstream to perform its recovery process.
  Any IXGWRITE to the logstream with non-zero return code will
  initiate a structure checkpoint to ensure data integrity.
  After an offload error, all successful IXGWRITE requests have
  RC/RSN=IxgRsnCodeWarning/IxgRsnCodeWowWarning (=04/0409)
  returned.  Even after the cause of the offload error has been
  fixed, logger still returns RC/RSN=04/0409 for an successful
  IXGWRITE.  The RC=0 will only be returned after a successful
  offload process.
    The logstream offload process is triggered when log records
  fill up the logstream to a pre-defined threshold value.  In the
  structure checkpoint process, log records will be purged from
  the logstream after being written to the SRDS.  This prevents
  logger to trigger the (successful) offload process.
  

Problem conclusion

• AIDS: RIDS/SYS RIDS/QMGR SYS QMGR
    GEN:
  SYSPLEXSQ
  
  *** END IMS KEYWORDS ***
  CQSLOG20 is modified to only initiating a structure checkpoint
  and write an error trace entry for the first encounter of
  IXGWRITE with RC = 04 (=IXGRETCODEWARNING) and RSN = 0409
  (=IXGRSNCOSEWOWWARNING).  Also, a successful IXG entry will be
  traced after a series of IXGWRITE with RC/RSN=04/0409.
  
  CQSTRLOG is modified to add a new subcode, TRLIXG, for a
  successful IXG service.
  
  CQSFTRC0 is modified to decode the new subcode.
  

Temporary fix

Comments

APAR Information

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

  PK41237

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

  UK28995

Modules/Macros

• CQSFTRC0 CQSLOG20 CQSTRLOG
  

Fix information

• Fixed component name

  IMS V10

• Fixed component ID

  5635A0100

Applicable component levels

• R010 PSY UK28995

     UP07/09/11 P F709

Fix is available

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