IT44384: Channel loops if a message on the transmit queue exceeds the MAXMSGL attribute of the Queue manager

APAR status

• Closed as program error.

Error description

• A message was published with a size which was close to the
  MAXMSGL of the Qmgr.
  The message was matched to a durable subscriber with its
  destination set to a remote queue so the Qmgr put the message to
  an transmission queue.
  The sender channel attempted to get the message from the XMITQ,
  but the MQGET failed with MQRC_TRUNCATED_MSG_FAILED, even though
  the buffer allocated by the sender channel was big enough for
  the message, including its properties.
  The reason the MQGET failed was: the message size + XMITQ header
  + pub/sub message properties exceeded the MAXMSGL of the Qmgr.
  The MQGET failed repeatedly, forever, and the channel could move
  no more messages.
  

Local fix

• Increase the MAXMSGL parameter on the queue manager, transmit
  queue, and channel.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Those using message channels (queue manager to queue manager
  channels), when messages close to the MAXMSGL are being
  published by the applications.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The sender channel code was not coded to expect this scenario.
  

Problem conclusion

• The sender channel code has been corrected to deal with this
  scenario.
  
  The sender channel code will now retry the MQGET in this
  scenario, using a Message Handle to receive the properties.  If
  the message can be retrieved in this way, it will be put to the
  Dead Letter Queue.  If the message cannot be retrieved the
  channel will stop.  In either case an error message will be
  written to the queue manager error log.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.30
  v9.3 LTS   9.3.0.20
  v9.x CD    9.4.1
  
  The latest available maintenance can be obtained from
  'IBM MQ Recommended Fixes'
  https://www.ibm.com/support/pages/recommended-fixes-ibm-mq
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'IBM MQ
  Planned Maintenance Release Dates'
  https://ibm.biz/mqplannedmaintenance
  
  ---------------------------------------------------------------
  

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:

Fix information

• Fixed component name

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels