IV26715: FALSE PING FAIL EVENTS GENERATED WHEN NTP CLOCK ADJUSTMENTS ARE MADE.

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Product: Tivoli Network Manager
    Version: 3.8
    Component: Poller
    
    Symptoms:  Very fast responses can appear to the poller to
    arrive before the request is sent, resulting in ping fail events
    where no such outage exists.
    
    When ITNM is processing very fast ping responses (in the order
    of millisecs) occasionally an anomaly occurs with the
    timestamps used for send/receive packets. The effect of this
    currently is that the rtt appears negative and a timeout is
    incorrectly triggered.
    
    Debug messages were introduced into the poller to log when this
    was occuring.  The timings of these messages can then be
    compared to the NTP daemon log file for adjustments in the NTP
    clock.
    
    A defensive test fix was created to recognise these conditions
    and prevent the false ping from being generated.
    
    Example of poller log message and NTP daemon log message
    
    Poller:
    2012-08-09 15:27:27 INFO     CPingCache.cc(53): Ping return time
    too small, setting to zero:  IP.IP.IP.IP 5280381 -1
    
    NTPD:
    Thu Aug  9 15:27:26 JST 2012
    sendpkt(fd=5 IP.IP.IP.IP,IP.IP.IP.IP, ttl=-8, 48)
    input_handler: fd=5 length 48 from 0aef00a8
    clock_filter(IP.IP.IP.IP, -0.061943, 0.00024, 0.00002)
    clock_update(IP.IP.IP.IP)
    select: prefer offset -0.061943
    Thu Aug  9 15:27:27 JST 2012
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All ITNM 3.9 Poller users.                                   *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * FALSE PING FAIL EVENTS GENERATED WHEN NTP CLOCK ADJUSTMENTS  *
    * ARE                                                          *
    * MADE.                                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * fix pack | 3.9.0-ITNMIP-FP0003                               *
    * fix pack | 3.8.0-ITNMIP-FP0007                               *
    ****************************************************************
    

Problem conclusion

  • Added code to fix problem when NTPD adjusts the clock.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV26715

  • Reported component name

    TIV NETWK MGR I

  • Reported component ID

    5724S4500

  • Reported release

    380

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-08-21

  • Closed date

    2012-10-08

  • Last modified date

    2013-01-24

  • 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

    TIV NETWK MGR I

  • Fixed component ID

    5724S4500

Applicable component levels

  • R380 PSN

       UP

  • R380 PSY

       UP

  • R390 PSN

       UP

  • R390 PSY

       UP

  • R401 PSN

       UP

  • R401 PSY

       UP



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Document information


More support for:

Tivoli Network Manager IP Edition

Software version:

380

Reference #:

IV26715

Modified date:

2013-01-24

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