IBM Support

IT22419: All username/password authentication requests hang. Queue manager is configured to request via PAM

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APAR status

  • Closed as program error.

Error description

  • A queue manager is configured (via an AUTHINFO object) to use
    PAM to provide username/password authentication.
    
    After an error in processing one of these, all subsequent
    requests hang.
    
    At least one FDC record is generated with the following details:
    
    Probe Id          :- XC514090
    Component         :- xlsRWMutexRequest
    Major Errorcode   :- xecL_W_LONG_LOCK_WAIT
    Probe Description :- AMQ6150: WebSphere MQ semaphore is busy.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users who have configured the queue manager to request
    username/password authentication using PAM, who suffer a failure
    within that mechanism (the root cause for that failure is
    outside the scope and control of the MQ product).
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    The process that is started to check the username/password using
    PAM is amqoampx.
    
    On one system we saw that:
    - this process could fail to write output back to the process
    that started it
    - the parent process would not be returned from its read() call,
    even though the process was ended.
    
    The queue manager holds a mutex while this activity takes place,
    to prevent changes to the AUTHINFO configuration from affecting
    currently-running PAM auth requests.
    
    This mutex is never released because of the failures mentioned
    above, and as a result, the queue manager ceases to be able to
    offer authentication to newly connecting applications.
    

Problem conclusion

  • The MQ code has been changed to use a more robust mechanism for
    waiting and reading the output from amqoampx into the process
    that starts it.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.8
    v9.0 CD    9.0.5
    v9.0 LTS   9.0.0.3
    
    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 number

    IT22419

  • 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

    2017-09-16

  • Closed date

    2017-10-17

  • Last modified date

    2017-10-17

  • 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:
17 October 2017