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IZ00735: AUTHENTICATION VERY SLOW ON CERTAIN PSERIES HARDWARE WITH POWER5+ CPU'S

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You can track all active APARs for this component.

APAR status

  • Closed as fixed if next.

Error description

  • OS Authentication for DB2 version 8.2 can be very slow in AIX or
    pSeries Linux on certain pSeries hardware with POWER5+ CPUs. The
    function cryptContextRealInit which makes ICC (IBM Cryptographic
    library for C) API calls.
    
    The problem exists on one of below environments:
      - Certain models of pSeries POWER5+ CPUs (AIX or Linux)
      or
      - Virtualized environments (LPARs) (not restricted to
        any specific CPU)
    
    Note:
      LPAR is not restricted to pSeries POWER5+ CPUS.  There are
      other LPAR configuration where ICC have the same problem like
      VMWare on Intel, for example.
    
    AIX tprof and perfpmr utilities show the bottleneck to be in the
    ICC library (shipped with DB2), libicclib.so. Using the AIX grof
    utility, it was further isolated to getbyte() which gets a byte
    of random data using the jitter from values obtained against the
    Timebase register (TBR). In the POWER5+ architecture, the clock
    sourse was changed to be a 512 MHZ fixed source, which the ICC
    code did not account for.
    
    The affected version of ICC is 1.4.x (1.4.1) which shipped in
    DB2 UDB (distributed) from 8.2.5 (Fixpak 11) and above.
    
    DIAGNOSING THE PROBLEM:
    To see what ICC version is being used in your environment please
    set diaglevel to 4, issue connect statement:
    db2 connect to <database alias> user <userID> using <password>
    the db2diag.log should report the ICC version:
    
    2010-09-02-13.53.14.629263-240 I426179C336 LEVEL: Info
    PID : 708760 TID : 1
    FUNCTION: DB2 Common, Cryptography, cryptContextRealInit,
    probe:100
    DATA #1 : String, 20 bytes
    ICC VERSION: 1.4.5.0
    DATA #2 : String, 45 bytes
    ICC INSTALL PATH: /home/db2fenc1/sqllib/lib32
    DATA #3 : String, 18 bytes
    ICC FIPS MODE: YES
    

Local fix

  • None.
    There is not a workaround to this issue.
    Please contact DB2 Technical Support and request a special build
    for this APAR if you are on an affected environment.
    The following OS command should show the library libicclib.so
    using an excessive percentage of CPU.
    
       tprof -skeuj -x sleep 5
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All DB2 client on AIX or virualize environments at service   *
    * levels from Version 8.1 Fix Pack 11 through to Version 8.1   *
    * Fix Pack 18.                                                 *
    * Effected AIX and Linux CPUs include:                         *
    * AIX on Power5, Power5+, Power6, Power7, and Power7+          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * "The issue is with ICC 1.4, but ICC 1.5 is not FIPS certified*
    *  and it can not be included in DB2 for this reason"          *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Request for special build with non-FIPS certified ICC        *
    * v1.5.25                                                     *
    ****************************************************************
    

Problem conclusion

  • Request special build.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IZ00735

  • Reported component name

    DB2 UDB ESE AIX

  • Reported component ID

    5765F4100

  • Reported release

    820

  • Status

    CLOSED FIN

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-06-26

  • Closed date

    2009-05-08

  • Last modified date

    2010-09-14

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

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

    IZ12129 IZ29155 IC72232 IC72233 IC72234 IC87788

Fix information

Applicable component levels

  • R820 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 820

Reference #: IZ00735

Modified date: 14 September 2010