IBM Support

IT13088: CHECKPOINT DURATION IN ONSTAT -G CKP/SYSCHECKPOINT CAN BE DIFFERENT FROM INSTANCE MESSAGE LOG

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APAR status

  • Closed as program error.

Error description

  • You may observe that the checkpoint duration as provided via
    onstat -g ckp or its equivalent entry in
    sysmaster:syscheckpoints can be different from the duration
    printed in the instance message log file (online.log).
    
    For an example of this situation in the instance message log you
    may refer to the instance message log file excerpt:
    
    13:44:04  Checkpoint Completed:  duration was 1 seconds.
    13:44:19  Thu Jan  7 - loguniq 95, logpos 0x1cc6018, timestamp:
    0x6e2da462 Interval: 8827
    
    13:44:19  Maximum server connections 1
    13:44:19  Checkpoint Statistics - Avg. Txn Block Time 0.000, #
    Txns blocked 0, Plog used 0, Llog used 2
    
    You can see the checkpoint duration is logged as being 1 second.
    However, you may notice that the timestamp of the following
    lines in the message is about 15 seconds later than the first.
    When you now look at the onstat -g ckp output
    
    8827       13:44:18 *User       95:0x1cc6018      16.0  0.0
    0.0   1      0.0   16.0  16.0  0         0       0        0
    2        0
    
    you will notice that the total duration of the checkpoint is
    printed there as 16.0 seconds. About same you will notice for
    the output of sysmaster:syscheckpoints:
    
    intvl              8827
    type               Blocking
    caller             User
    clock_time         1452170658
    crit_time          1.67605046e-05
    flush_time         0.000169024979
    cp_time            15.96093922200
    ...
    
    Essentially the checkpoint duration was only 1 second, though,
    and the reading from onstat -g ckp and sysmaster:syscheckpoint
    can be misleading with respect to this.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Informix users observing significant difference of           *
    * checkpoint duration reported in online.log files vs. onstat  *
    * -g ckp output (or sysmaster:syscheckpoints )                 *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Update to IBM Informix Server 11.70.xC9                      *
    ****************************************************************
    

Problem conclusion

  • Problem Fixed In IBM Informix Server 11.70.xC9
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT13088

  • Reported component name

    INFORMIX SERVER

  • Reported component ID

    5725A3900

  • Reported release

    B70

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-01-08

  • Closed date

    2017-06-09

  • Last modified date

    2017-06-09

  • 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

    INFORMIX SERVER

  • Fixed component ID

    5725A3900

Applicable component levels

  • RB70 PSY

       UP

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Document Information

Modified date:
09 June 2017