IT19169: MQ APPLIANCE HA QUEUE MANAGERS NOT TOLERANT OF NETWORK PING FAILURES.

APAR status

• Closed as program error.

Error description

• A failover occurs from primary to standby queue managers in a
  HA/DR environment.  This is soon followed by failover back to
  the primary queue manager.
  
  The IBM Appliance system log contains entries such as this:
  
  Dec 16 16:50:51 (none) pengine[24787]:  warning: unpack_rsc_op:
  Processing failed op monitor for QMGR on x.y.a.b: not running
  (7)
  Dec 16 16:50:51 (none) pengine[24787]:    error: color_instance:
  Pre-allocation failed: got x.y.a.b instead of x.y.a.b
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Demote  QMGR_drbd:0#011(Master -> Slave x.y.a.b)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Promote QMGR_drbd:1#011(Slave -> Master x.y.a.b)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Stop    QMGR_fs#011(x.y.a.b)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Stop    QMGR#011(x.y.a.b)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Move    QMGR_DR_IP#011(Started x.y.a.b -> x.y.a.b)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Demote  QMGR_DR_drbd:0#011(Master -> Slave x.y.a.b - blocked)
  Dec 16 16:50:51 (none) pengine[24787]:   notice: LogActions:
  Move    QMGR_DR_drbd:0#011(Slave x.y.a.b -> x.y.a.b)
  

Local fix

• It may be possible to work around or decrease the likelihood of
  this problem occurring by fixing any network issues that may be
  affecting connectivity between IBM MQ Appliances
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of the IBM MQ Appliance who have configured a combination
  of HA and DR and who have unreliable network connectivity may be
  affected by this problem.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A transient DR ping failure could have resulted in a queue
  manager briefly starting on the HA secondary appliance before
  switching back to the HA primary appliance.  If a network is
  particularly unreliable then this failover behaviour may have
  happened frequently.
  

Problem conclusion

• The code that detects whether the DR secondary IBM MQ Appliance
  can be contacted was modified so that it is more tolerant of
  transient network failures.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.7
  v9.0 CD    9.0.2
  
  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 APPL M20

• Fixed component ID

  5725S1400

Applicable component levels

• R800 PSY

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