PH33737: IBM MQ Z/OS:ABN=5C6-00D70121

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The dump of ABN=5C6-00D70121 was requested  at CSQPPGET.
  R15=reason code=00D70121  means CSQP_LOGIC_ERROR
  R3=PSID=00030000> PANC_HI_PSID (Highest valid Pageset ID 00-99)
  
  MSTR joblog shows the qmgr terminated abnormally after it
  issued ABN=5C6-00D70121,which followed CSQP017I and
  CSQP014E(IEC070I 034(004)-220 End of volume - Non-extended
  addressable. ) for page set 1  and MQRC_STORAGE_MEDIUM_FULL.
  CSQP017I was caused by one client application.
  MQ dev confirms that there exists a timing window when using
  the tuning parameter MaxShortMsgs and putting to a queue with a
  full pageset, while a getter is also processing the queue.
  

Local fix

• Issue RECOVER QMGR(TUNE MAXSHORTMSGS 0)
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0, Release 1          *
  *                 Modification 0 and Release 2 Modification 0. *
  ****************************************************************
  * PROBLEM DESCRIPTION: There exists a timing window when using *
  *                      a non-zero value for the MaxShortMsgs   *
  *                      tuning parameter and putting a small    *
  *                      message to a queue on a full page set.  *
  *                      If this happens at the same time as a   *
  *                      getter pushes the queue depth below the *
  *                      MaxShortMsgs value, then this may       *
  *                      result in a corrupted message being     *
  *                      placed on the queue.                    *
  *                                                              *
  *                      Attempts to clear the queue or get the  *
  *                      message will result in a 5C6-00D70121   *
  *                      abend in CSQPPGET. If the scavenger     *
  *                      instead tries to process the message,   *
  *                      for example if the message expires,     *
  *                      then the QMGR may also terminate with a *
  *                      6C6-00E50702 abend.                     *
  ****************************************************************
  If internal put processing fails due to a page set being full,
  the put will be retried once. If the initial put occurs while
  over the MaxShortMsgs value, and the message is small, then the
  message data will be inlined on the same page. When retrying the
  put, if the queue depth has dropped below the MaxShortMsgs
  value, then the message data will be placed on a separate page.
  Unfortunately, some internal state variables are not reset when
  retrying the put, resulting in the message being corrupted.
  

Problem conclusion

• The code has been corrected to consistently process inline
  messages when using a non-zero value for the MaxShortMsgs tuning
  parameter.
  

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:

  UI73958 UI73959 UI73960

Modules/Macros

• CSQIMPU2
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI73960

     UP21/03/03 P F103 ¢

• R100 PSY UI73959

     UP21/03/03 P F103 ¢

• R200 PSY UI73958

     UP21/03/03 P F103 ¢

Fix is available

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