IT12875: CLUSTER CHANNEL STARTUP DELAYED.

APAR status

• Closed as program error.

Error description

• When a message is put into a remote/cluster queue within a TMF
  user transaction, while the corresponding transmit queue is
  empty or almost empty, it can take up to 60 seconds after the
  end of the transaction until the message is transmitted. As a
  side effect automatic channel starts can also be delayed.
  

Local fix

• Set Environment Variable MQQMSHKEEP.
  
  *** Note: The Setting for the Environment Variable is in Seconds
  and has an impact on the frequency of some housekeeping. An
  increase in CPU Utilization would be expected from the increased
  frequency of this houskeeping.
  
  The correct procedure for setting the environment variable:
  1. Freeze and stop MQS-QMGRSVR00 in Pathway
  2. Check that the process is stopped, if not stop it from TACL
  3. In Pathcom:
  ALTER MQS-QMGRSVR00,ENV MQQMSHKEEP=20
  
  To delete the environment variable for the server use the
  following syntax:
  ALTER SERVER MQS-QMGRSVR00,DELETE ENV MQQMSHKEEP
  

Problem summary

• When a message is put into a cluster queue within
  a TMF user transaction and while the corresponding transmit
  queue is empty or almost empty, it can take up to 60 seconds
  after the end of the transaction until the message is
  transmitted. As a side effect automatic channel starts can
  also be delayed.
  

Problem conclusion

• The WebSphere MQ product code has been corrected such that
  in the scenario above, the END TRANSACTION handling will
  catch all END TRANSACTION events instantaneously for messages
  to be transmitted to other cluster nodes.
  

Temporary fix

• Set Environment Variable MQQMSHKEEP.
  *** Note: The Setting for the Environment Variable is in Seconds
  and has an impact on the frequency of some housekeeping. An
  increase in CPU Utilization would be expected from the increased
  frequency of this housekeeping.
  The correct procedure for setting the environment variable:
  1. Freeze and stop MQS-QMGRSVR00 in Pathway
  2. Check that the process is stopped, if not stop it from TACL
  3. In Pathcom:ALTER MQS-QMGRSVR00,ENV MQQMSHKEEP=20
  To delete the environment variable for the server use the
  following syntax:
    ALTER SERVER MQS-QMGRSVR00,DELETE ENV MQQMSHKEEP
  

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

  WEBS MQ NSS ITA

• Fixed component ID

  5724A3902

Applicable component levels