IT42224: IBM MQ appliance queue manager resync might be unexpectedly slowfor some of the QMgrs between active and standby/DR nodes.

APAR status

• Closed as program error.

Error description

• When the IBM MQ appliance HA or DR queue manager synchronizes
  the data for many queue managers at the same time from active
  node to standby or DR  node the re-sync might be unexpectedly
  slower for some of the queue managers. For example, QM1 started
  first to re-sync the data might end finishing last and other
  queue managers started after QM2 might finish before QM1 though
  the data to be re-synced is same each QM.
  
  Excerpt from messages log:
  
  The log indicates QM1 took 5818 seconds(96+ minutes) to complete
  the resync whereas other queue managers
  took less time though the data to be re-synced was same for each
  QM.
  
  2022-09-14 23:53:15.026247+02:00 [localhost] kernel:
  [6736368.127582] drbd drbd_QM01/0 drbd1  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  2022-09-14 23:53:20.494255+02:00 [localhost] kernel:
  [6736373.583301] drbd drbd_QM02/0 drbd2  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  2022-09-14 23:53:26.954255+02:00 [localhost] kernel:
  [6736380.028661] drbd drbd_QM03/0 drbd3  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  2022-09-14 23:53:32.680481+02:00 [localhost] kernel:
  [6736385.743272] drbd drbd_qm04/0 drbd4  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  2022-09-14 23:53:38.366248+02:00 [localhost] kernel:
  [6736391.415686] drbd drbd_QM05/0 drbd5  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  ...
  2022-09-14 23:55:38.994249+02:00 [localhost] kernel:
  [6736511.759946] drbd drbd_QM24/0 drbd24  IBMHOST1: Began resync
  as SyncSource (will sync 41943040 KB [10485760 bits set]).
  ...
  2022-09-15 00:01:14.017753+02:00 [localhost] kernel:
  [6736845.998921] drbd drbd_QM24/0 drbd24 MQAPICRR02: Resync done
  (total 335 sec; paused 0 sec; 125200 K/sec)
  ...
  2022-09-15 00:02:16.590262+02:00 [localhost] kernel:
  [6736908.424696] drbd drbd_QM03/0 drbd3  IBMHOST1: Resync done
  (total 529 sec; paused 0 sec; 79284 K/sec)
  2022-09-15 00:02:38.207232+02:00 [localhost] kernel:
  [6736929.991668] drbd drbd_QM05/0 drbd5  IBMHOST1: Resync done
  (total 539 sec; paused 0 sec; 77816 K/sec)
  ...
  2022-09-15 00:05:30.946239+02:00 [localhost] kernel:
  [6737102.319711] drbd drbd_QM04/0 drbd4  IBMHOST1: Resync done
  (total 718 sec; paused 0 sec; 58416 K/sec)
  ...
  2022-09-15 00:06:00.570265+02:00 [localhost] kernel:
  [6737131.873773] drbd drbd_QM02/0 drbd2  IBMHOST1: Resync done
  (total 760 sec; paused 0 sec; 55188 K/sec)
  ...
  2022-09-15 01:30:13.522250+02:00 [localhost] kernel:
  [6742172.962743] drbd drbd_QM01/0 drbd1  IBMHOST1: Resync done
  (total 5818 sec; paused 0 sec; 7208 K/sec)
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users using queue managers in High Availability or Disaster
  Recovery configuration in MQ appliance
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A defect in the DRBD component used for disk replication caused
  slow resync for some of the queue managers when the appliance
  was re-syncing many queue managers at the same time.
  

Problem conclusion

• MQ appliance code has been modified to upgrade the DRBD version
  to resolve the slow re-sync issue.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.7
  v9.x CD    9.3.0
  
  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 APPL M2002 V

• Fixed component ID

  5737H4701

Applicable component levels