IT28243: MQ incorrectly writes channel completion messages to the channelinitiation queue for SVRCONN channels

APAR status

• Closed as program error.

Error description

• IBM MQ incorrectly writes channel completion messages with an
  MQMD format of MQCHCOM to SYSTEM.CHANNEL.INITQ when SVRCONN
  channels end.
  
  These extraneous messages can lead to an increase of CURDEPTH on
  the SYSTEM.CHANNEL.INITQ which may inhibit the channel initiator
  from performing its scheduled tasks in a timely manner.
  
  Under extreme circumstances, the initiation queue may fill
  preventing new trigger messages from being queued.
  
  The queue manager error log may contain AMQ7208 error entries
  indicating that the channel initiation queue is full
  (MQRC_Q_FULL).
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Any users that connect clients to a queue manager could generate
  unnecessary channel completion messages for SVRCONN channels
  when the client connections are closed.
  
  Whether the extraneous messages have a noticeable impact on the
  normal operation of the channel initiator (channel triggering,
  channel retry and healthchecking) will depend upon the number of
  connections closures and the existing workload on the channel
  initiator.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a channel agent terminates, it performs a check to see if a
  channel initiator will be scheduled to wake in time to perform a
  channel retry, it may also produce a channel stopped event if
  configured - this process is unnecessary for SVRCONN channel
  agents.
  

Problem conclusion

• The logic in channel termination was corrected to the expected
  behaviour for SVRCONN channel agents.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.13
  v9.0 LTS   9.0.0.8
  v9.1 CD    9.1.3
  v9.1 LTS   9.1.0.3
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  IBM MQ BASE MP

• Fixed component ID

  5724H7251

Applicable component levels