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PI07111: THE TIME PROVIDED BY DB2 TO IDAA DID NOT ACCOUNT FOR THE LEAP SECONDS, SO IT WAS OFF FROM UTC BY 25S

A fix is available

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APAR status

  • Closed as program error.

Error description

  • The IDAA time is synchronized with the time of the DB2 system
    that acts as time reference system. DB2 sends the current time
    to IDAA with each query. IDAA uses this information to set its
    own system time. All IDAA-related functionality relying on
    system time expects to work with UTC timestamps. The time
    provided by DB2 did not account for the leap seconds, so it was
    off from UTC by 25s (or whatever was configured in DB2). The
    effect was that timestamps provided in the query history, in
    IDAA events written to the z/OS syslog, and expressions
    involving CURRENT_TIME or CURRENT_TIMESTAMP special registers
    were 25s off.  This APAR adjusts the calculation of the
    timestamp passed from DB2 to IDAA to include the leap seconds.
    Thus, the IDAA system has the correct UTC timestamp available
    now.
    **************************************************************
    Additional Symptoms and Keywords:
     IDAA IDAAV2R1/K IDAAV3R1/K IDAAV4R1/K
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All DB2 users of the IBM Data Analytics      *
    *                 Accelerator (IDAA).                          *
    ****************************************************************
    * PROBLEM DESCRIPTION: An offloaded query that returns the     *
    *                      CURRENT TIMESTAMP special register      *
    *                      contains a different value compared to  *
    *                      running the query on DB2.               *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    An application offloads a query that references the CURRENT
    TIMESTAMP special register.  The same query is immediately
    executed again in DB2.  The timestamp returned by the offloaded
    query is approximately 24 seconds greater that the value
    returned when the query is executed on DB2.
    During a query offload, DB2 sends a synchronization timestamp
    to IDAA.  The problem occurs because this synchronization
    timestamp did not include leap seconds, resulting in a 24
    second difference in the CURRENT TIMESTAMP value for offloaded
    queries.
    This difference in value can also occur for the CURRENT TIME
    special register.
    

Problem conclusion

  • DB2 has been changed to account for leap seconds in the IDAA
    synchronization timestamp.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI07111

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-12-02

  • Closed date

    2014-02-28

  • Last modified date

    2014-04-02

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    UI15618 UI15617

Modules/Macros

  •    DSNLXENV DSNLXROP DSNLXRSQ DSNLXSR  DSNLZOSR
    DSNTTIM  DSNXESSR
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RA10 PSY UI15617

       UP14/03/18 P F403

  • RB10 PSY UI15618

       UP14/03/18 P F403

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.



Document information

More support for: DB2 for z/OS

Software version: A10

Reference #: PI07111

Modified date: 02 April 2014


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