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IT22173: High CPU in amqrrmfa process on a non-clustered queue manager

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The amqrrmfa process went into a loop in xlsWaitEvent function
    because futex wait syscall returned with EINVAL.
    
    The thread stack in the trace is likely to show the following
    stack.
    
     14:17:12.551750     3077.1       CONN:000002      Thread stack
    (from libmqmcs_r.so)
     14:17:12.552768     3077.1       CONN:000002      -> rrmMain
     14:17:12.552777     3077.1       CONN:000002      ->
    rrmRepository
     14:17:12.552781     3077.1       CONN:000002      -> rrmGetMsg
     14:17:12.552793     3077.1       CONN:000002      -> MQGET
     14:17:12.552799     3077.1       CONN:000002      -> zstMQGET
     14:17:12.552809     3077.1       CONN:000002      -> zifMQGET
     14:17:12.552814     3077.1       CONN:000002      -> zsqMQGET
     14:17:12.552820     3077.1       CONN:000002      -> kpiMQGET
     14:17:12.552826     3077.1       CONN:000002      ->
    kqiWaitForMessage
     14:17:12.552831     3077.1       CONN:000002      ->
    kqiWaitForABit
     14:17:12.552837     3077.1       CONN:000002      ->
    xcsWaitEventSem
     14:17:12.552842     3077.1       CONN:000002      ->
    xlsWaitEvent
     14:17:12.552850     3077.1       CONN:000002      ->
    xtrTAisMatch
    
     strace captured for the affected process likely to show
    repeated futex calls returning with EINVAL.
    
      0.000037 futex(0x7f4b3c16829c, FUTEX_WAIT, 0,
    {18446744073707814474, 18446744073477551616}) = -1 EINVAL
    (Invalid argument) <0.005366>
         0.005398 futex(0x7f4b3c16829c, FUTEX_WAIT, 0,
    {18446744073707814474, 18446744073477551616}) = -1 EINVAL
    (Invalid argument) <0.000009>
         0.000037 futex(0x7f4b3c16829c, FUTEX_WAIT, 0,
    {18446744073707814474, 18446744073477551616}) = -1 EINVAL
    (Invalid argument) <0.000008>
         0.000037 futex(0x7f4b3c16829c, FUTEX_WAIT, 0,
    {18446744073707814474, 18446744073477551616}) = -1 EINVAL
    (Invalid argument) <0.000008>
         0.000036 futex(0x7f4b3c16829c, FUTEX_WAIT, 0,
    {18446744073707814474, 18446744073477551616}) = -1 EINVAL
    (Invalid argument) <0.000008>
    

Local fix

  • NA
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users running a queue manager in a system with NTP
    synchronization or users that change the system clock when the
    queue manager is running might be affected by this problem.
    
    
    Platforms affected:
    Linux on Power, Linux on S390, Linux on x86-64, Linux on x86,
    Linux on zSeries
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    The infinite loop occurred because IBM MQ did not handle the
    EINVAL error code from the futex system call.
    

Problem conclusion

  • IBM MQ has been modified to handle the EINVAL error code from
    the futex system call.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.5       7.5.0.9
    v8.0       8.0.0.8
    v9.0 CD    9.0.4
    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

    IT22173

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7241

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-08-28

  • Closed date

    2017-09-22

  • Last modified date

    2017-09-22

  • 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

    5724H7241

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCPQ63","label":"APAR \/ Maintenance"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.5","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
22 September 2017