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

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You can track all active APARs for this component.

 

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 number

    IT14344

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-03-16

  • Closed date

    2016-09-22

  • Last modified date

    2017-06-01

  • 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

       UP

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Document Information

Modified date:
01 June 2017