IT14344: MQCONN hang and queue manager does not accept new connections

APAR status

• Closed as program error.

Error description

• The queue manager is not accepting new connections when
  connection authentication(e.g. SYSTEM.DEFAULT.AUTHINFO.IDPWOS)
  is enabled.
  This problem is intermittent. Applications issuing MQCONN will
  be unresponsive. The SIGUSR2 FDCs generated during the hang
  likely to show MQ amqzlaa0 threads waiting on
  xlsRWMutexRequest() in zfu_as_AuthenticateUser().
  
  ---------{ zfu_as_AuthenticateUser
  ...
  ----------{ xlsRWMutexRequest
  -----------{ xlsRWLockState
  -----------} xlsRWLockState rc=OK
  -----------{ xlsRWMutexCheckLock
  -----------} xlsRWMutexCheckLock rc=OK
  -----------{ xlsRWUnlockState
  -----------} xlsRWUnlockState rc=OK
  -----------{ xtmRequestCallback
  -----------} xtmRequestCallback rc=OK
  -----------{ xtmCancelCallback
  -----------} xtmCancelCallback rc=OK
  -----------{ xlsRWLockState
  -----------} xlsRWLockState rc=OK
  -----------{ xlsRWUnlockState
  -----------} xlsRWUnlockState rc=OK
  -----------{ xtmRequestCallback
  -----------} xtmRequestCallback rc=OK
  -----------{ xcsFFST
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users running MQ applications which make a lot of connections in
  a short period of time to a queue manager running on Solaris
  
  
  Platforms affected:
  Solaris SPARC, Solaris x86-64
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A coding error with the MQ queue manager exposed a timing window
  where, during periods of high contention for internal locks, it
  was possible to fail to wake the next thread waiting on the
  lock.
  

Problem conclusion

• The MQ queue manager logic has been corrected to correctly wake
  waiting threads in this situation.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.6
  v9.0 CD    9.0.1
  v9.0 LTS   9.0.0.1
  
  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

  WMQ BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels

• R800 PSY

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