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JR58579: LOG DEPENDENCY STOPS MOVING AND SEEING OCCASIONAL DATA LOSS.

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • DMSHOWLOGDEPENDENCY is not being updated even though we are
    several logs past and there are no open/long running
    ransactions.
    This may result in data loss as well.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * This issue affects customers using CDC for SqlServer as a    *
    * source datastore, particularly configurations with smaller   *
    * virtual log files and frequent backups.                      *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * The data loss would occur if the CDC for Microsoft Sql       *
    * Server would accumulate log entries in a buffer, then        *
    * complete processing at a boundary of a virtual log file,     *
    * followed by detectingthat a transaction log backup has been  *
    * completed. Smaller virtual log files along with more         *
    * frequent backups would create a higher chance for the        *
    * observed behaviour to be exhibited. In this scenario, CDC    *
    * would attempt to re-read that section of log, but since the  *
    * log reading position had already advanced, the same section  *
    * of log was never processed again. This was causing data      *
    * loss.                                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to IIDR 11.4.0.0-5036 or later for Microsoft         *
    * SqlServer.                                                   *
    ****************************************************************
    

Problem conclusion

  • Upgrading to IIDR 11.4.0.0-5036 or later resolves the issue.
    

Temporary fix

Comments

APAR Information

  • APAR number

    JR58579

  • Reported component name

    IS CDC SQL

  • Reported component ID

    5725E30SQ

  • Reported release

    B40

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-10-13

  • Closed date

    2017-10-24

  • Last modified date

    2017-10-24

  • 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

    IS CDC SQL

  • Fixed component ID

    5725E30SQ

Applicable component levels

  • RB33 PSN

       UP

  • RB40 PSY

       UP

  • RA20 PSN

       UP

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Document Information

Modified date:
24 October 2017