IT41625: RDQM configured for both HA and DR unable to run on any node after frequent connection interruptions

APAR status

• Closed as program error.

Error description

• RDQM configured for both HA and DR is unable to run on any node
  after frequent connection interruptions even with APAR IT38764
  included. When there is a failover initiated, though a stop on
  the stacked drbd resource is issued, the resource will never be
  restarted. The DR/HA queue manager's stacked DRBD  resource will
  be  stuck in disk less state. In the logs we can find below
  entries
  Jul 11 20:58:48 ### rdqmd: Waiting for Diskless stacked resource
  '###.dr' to be Secondary
  Jul 11 20:58:54 ### rdqmd: Stopped resource 'ms_drbd_dr_###'
  Jul 11 20:58:54 ### rdqmd: Set target-role=Master for resource
  'ms_drbd_dr_#'
  

Local fix

• Suspend the primary node then resume it.
  rdqmadm -s
  rdqmadm -r
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All MQ users who have configured RDQM for high availability (HA)
  and disaster recovery (DR).
  
  
  Platforms affected:
  Linux on x86-64
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  During failover when a stop on the stacked resource is issued,
  MQ will set the target-role to Master this will override the
  stop of stacked resource which can happen in a small timing
  window when quorum returns before Pacemaker stops the stacked
  resource. The stop of stacked resource issued is not synchronous
  and we are not waiting for resource to stop before changing the
  target role. APAR IT38764 attempted to fix a similar issue
  previously, but did not account for this additional timing
  window.
  

Problem conclusion

• The code has been modified to wait for stop on drbd stacked
  resource to complete before changing the target role.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.10
  v9.3 LTS   9.3.0.5
  v9.x CD    9.3.3
  
  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

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels