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IC73186: DB2 MIGHT ENCOUNTER 'DEAD LATCH' ISSUE AND INSTANCE WILL HANG.

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You can track all active APARs for this component.

APAR status

  • Closed as fixed if next.

Error description

  • To identify the problem, issue 'db2fodc -hang' command to
    generate diagnostic information. Then in stack files you will
    see 2 agents similar to the followings:
    ================================
    <StackTrace>
    sqloXlatchConflict
    sqlpm_write_appl_locks
    sqm_snap_appl_locks
    sqm_snap_db_locks
    sqlmonssagnt
    
    <LatchInformation>
    Waiting on latch type: (SQLO_LT_SQLP_TENTRY__tranEntryLatch) -
    Address: (7000001bc956e68), Line: 748, File:
    /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqlpi_inlines.h
    
    Holding Latch type: (SQLO_LT_sqeLocalDatabase__dblatch) -
    Address: (780000000780328), Line: 395, File: sqlmutil.C
    HoldCount: 1
    Holding Latch type: (SQLO_LT_sqeAppServices__m_appServLatch) -
    Address: (7800000002f04f8), Line: 7822, File: sqlmonss.C
    HoldCount: 1
    Holding Latch type: (SQLO_LT_sqeApplication__masterAppLatch) -
    Address: (7000002513101c4), Line: 327, File:
    /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqle_app_service
    s.h
    HoldCount: 1
    
    ...
    
    <StackTrace>
    sqloXlatchConflict
    sqlkdDispatchRequest
    sqlkdInterrupt
    sqlrr2pd
    sqlrkcmt
    sqlrkcm
    sqlrrcom_dps
    sqlrr_xcommit
    
    <LatchInformation>
    Waiting on latch type: (SQLO_LT_sqeApplication__masterAppLatch)
    - Address: (7000002513101c4), Line: 997, File:
    /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqle_application
    .h
    
    Holding Latch type: (SQLO_LT_SQLP_TENTRY__tranEntryLatch) -
    Address: (7000001bc956e68), Line: 748, File:
    /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqlpi_inlines.h
    HoldCount: 1
    ================================
    The deadlatch is constructed by 'masterAppLatch' and
    'tranEntryLatch'.
    
    You will have to recycle the instance to get out of the 'dead
    latch' situation.
    

Local fix

  • The problem only occurs when you're getting snapshot. So it can
    be avoided if you don't get any snapshot.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * To identify the problem, issue 'db2fodc -hang' command to    *
    * generate diagnostic information. Then in stack files you     *
    * will see 2 agents similar to the followings:                 *
    * ================================                             *
    * <StackTrace>                                                 *
    * sqloXlatchConflict                                           *
    * sqlpm_write_appl_locks                                       *
    * sqm_snap_appl_locks                                          *
    * sqm_snap_db_locks                                            *
    * sqlmonssagnt                                                 *
    *                                                              *
    * <LatchInformation>                                           *
    * Waiting on latch type: (SQLO_LT_SQLP_TENTRY__tranEntryLatch) *
    * - Address: (7000001bc956e68), Line: 748, File:               *
    * /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqlpi_inlines.
    *                                                              *
    * Holding Latch type: (SQLO_LT_sqeLocalDatabase__dblatch) -    *
    * Address: (780000000780328), Line: 395, File: sqlmutil.C      *
    * HoldCount: 1                                                 *
    * Holding Latch type: (SQLO_LT_sqeAppServices__m_appServLatch) *
    * - Address: (7800000002f04f8), Line: 7822, File: sqlmonss.C   *
    * HoldCount: 1                                                 *
    * Holding Latch type: (SQLO_LT_sqeApplication__masterAppLatch) *
    * - Address: (7000002513101c4), Line: 327, File:               *
    * /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqle_app_servi
    * HoldCount: 1                                                 *
    *                                                              *
    * ...                                                          *
    *                                                              *
    * <StackTrace>                                                 *
    * sqloXlatchConflict                                           *
    * sqlkdDispatchRequest                                         *
    * sqlkdInterrupt                                               *
    * sqlrr2pd                                                     *
    * sqlrkcmt                                                     *
    * sqlrkcm                                                      *
    * sqlrrcom_dps                                                 *
    * sqlrr_xcommit                                                *
    *                                                              *
    * <LatchInformation>                                           *
    * Waiting on latch type:                                       *
    * (SQLO_LT_sqeApplication__masterAppLatch) - Address:          *
    * (7000002513101c4), Line: 997, File:                          *
    * /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqle_applicati
    *                                                              *
    * Holding Latch type: (SQLO_LT_SQLP_TENTRY__tranEntryLatch) -  *
    * Address: (7000001bc956e68), Line: 748, File:                 *
    * /view/db2_v97fp2_aix64_s100514/vbs/engn/include/sqlpi_inlines.
    * HoldCount: 1                                                 *
    * ================================                             *
    * The deadlatch is constructed by 'masterAppLatch' and         *
    * 'tranEntryLatch'.                                            *
    *                                                              *
    * You will have to recycle the instance to get out of the      *
    * 'dead latch' situation.                                      *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to db2 version 9.7 fp 4                              *
    ****************************************************************
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    IC73186

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    910

  • Status

    CLOSED FIN

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-12-10

  • Closed date

    2010-12-10

  • Last modified date

    2010-12-10

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

    IC72224

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

Fix information

Applicable component levels

  • R910 PSN

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.1

Reference #: IC73186

Modified date: 10 December 2010