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IC93951: THE DB2 INSTANCE MAY HANG OR TRAP ON LINUX WHEN USING A HIGH NUM_INITAGENTS SETTING

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Using a high NUM_INITAGENTS setting (~1000 or higher) may result
    in a hang or trap on DB2 / Linux.  The high setting results in
    the creation of an additional segment for the DBMS memory set
    during instance startup processing (db2start).  The address
    space assigned to the new segment for the db2sysc process at
    this point in time may not be available in the db2wdog
    (watchdog) process.  The watchdog may not then be able to
    function properly, resulting in unpredictable symptom, including
    problems related to managing FMP processes.
    
    This problem may be more common in environments using address
    space randomization (ASLR).
    

Local fix

  • reduce num_initagents setting to less than 1000
      OR
    disable address space layout randomization (set
    kernel.randomize_va_space=0)
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * systems with a high NUM_INITAGENTS configuration (eg. >      *
    * 1000)                                                        *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 Version 9.7 Fix Pack 9                        *
    ****************************************************************
    

Problem conclusion

  • Problem first fixed in DB2 Version 9.7 Fix Pack 9
    

Temporary fix

  • See Local Fix
    

Comments

APAR Information

  • APAR number

    IC93951

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    970

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-07-05

  • Closed date

    2013-12-18

  • Last modified date

    2013-12-18

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

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

    IC93952

Modules/Macros

  • sqe
    

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IC93951

Modified date: 18 December 2013