IT17071: MQ APPLIANCE DNS CONFIGURATION CAUSED MEMORY LEAK

APAR status

• Closed as program error.

Error description

• A memory leak was seen on an IBM MQ Appliance.  This
  manifested itself in the IBM MQ Appliance by a system
  reboot, caused by the internal throttling facility.
  
  An IBM MQ Appliance error report may show an error such as this:
  
  Throttler forced box reload at 20YYDDMMT032955.009Z, reason: Low
  Memory
  

Local fix

• This problem was caused by a misconfigured DNS setting so the
  workaround is to correct that configuration.
  
  For example, in this case an extra blank name server was
  configured:
  
    show dns
    dns [up]
    ---
    admin-state enabled
    search-domain searchdomain
    search-domain searchdomain.com
    search-domain othersearchdomain
    name-server 0.0.0.0 53 53 3                <- extra, incorrect
  name server
    name-server 10.254.85.118 53 53 3
    name-server 10.254.85.119 53 53 3
    ip-preference 4
    force-ip-preference off
    load-balance round-robin
    retries 2
    timeout 5 Seconds
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of the IBM MQ Appliance who have configured their DNS
  settings may be affected by this issue
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A problem was identified in the Appliance code which handles
  domain name resolution.  If this name resolution processing
  failed due to misconfigured DNS settings then memory could be
  leaked from the system.  If the DNS configuration was not
  corrected then the system may eventually run low on memory and
  be automatically restarted.
  

Problem conclusion

• The IBM MQ Appliance code was changed so that the memory leak
  was fixed.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.6
  
  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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