PM85756: ABEND0C4 CMQXRSTF +00256 13/04/23 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• ABEND0C4 CMQXRSTF +00256
  Change Team finds that when a client is browsing a message
  on a transmission queue with a small buffer the MQGET returns
  MQRC 2079 ( MQRC_TRUNCATED_MSG_ACCEPTED ) and CSQXADPM invokes
  CSQAVICD to perform data-conversion. However, before doing so
  it sets the lCompCode and lReason to 0 (these would have been
  set to 1 and 2079). CSQAVICD then detects that a message with
  an XQH is being processed. However, the amount of message data
  available is not enough to perform the data conversion (due to
  the smaller buffer size). As lCompCode is now 0, CSQAVICD sets
  lCompCode to 1 and lReason to 2119, MQRC_NOT_CONVERTED
  This then results in subsequent processing not detecting that
  a truncated message was being processed, thus leading to the
  ABEND0C4.
  ADDITIONAL SYMPTOM :
  FFST in RSTSENDASYNCMESSAGE for Message length error
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 1 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: After applying PTF UK83816 a multiplex  *
  *                      client browsing a transmission queue    *
  *                      receives RC=2119. CHINIT gets an 0C4    *
  *                      abend in program CMQXRSTF. Message      *
  *                      CSQX068I message may also appear in     *
  *                      CHINIT output.                          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Multiplex client does an MQGET on a transmission queue with a
  small buffer and using options MQGMO_ACCEPT_TRUNCATED_MSG +
  MQGMO_CONVERT (and internally receives a MQCC=1, MQRC=2079)
  (MQRC_TRUNCATED_MSG_ACCEPTED). However because of PTF UK83816
  the compcode is reset to zero before calling CSQAVICD to do the
  convert. CSQAVICD detects that the message has an XQH and that
  there is not enough message data to perform the conversion.
  CSQAVICD, on seeing that the MQCC is now zero, sets a new
  compcode of 2, RC=2119 (MSG_NOT_CONVERTED).
  
  This causes rstCheckForOneMessage to invoke
  rstHandleMsgExpansion to obtain a buffer three times larger than
  the existing one in order to attempt the convert. However it
  copies from the old staging area specifying a length larger than
  the old staging area itself, possibly getting an 0C4 abend in
  CMQXRSTF.
  
  If there is no 0C4 then any subsequent MQGET from the
  transmission queue will request a buffer three times larger than
  the previous one which may eventually result in storage
  constraint within the CHINIT and for the scavenger to be
  invoked, as indicated by message CSQX068I.
  

Problem conclusion

• Changed CSQXADPM so that the CompCode and Reason code are only
  set to zero if the conversion in CSQAVICD is redriven.
  100Y
  CSQACCF
  CSQACSTR
  CSQACS64
  CSQALOCT
  CSQAVICD
  CSQXADPM
  CSQXCNVT
  CSQXLOCT
  CSQXSPRT
  HMS7100J
  

Temporary fix

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

Comments

APAR Information

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

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

  UK93834

Modules/Macros

• CSQACCF  CSQACSTR CSQACS64 CSQALOCT CSQAVICD
  CSQXADPM CSQXCNVT CSQXLOCT CSQXSPRT HMS7100J
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R100 PSY UK93834

     UP13/06/14 P F306 «

Fix is available

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