IBM Support

PH29166: MESSAGE ENGINE DEADLOCK PROBLEM

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APAR status

  • Closed as program error.

Error description

  • At 12:30:09:355 on June 23rd, the background processing that
    was being executed on the application side failed and the
    following error was output.
    ----------
    [20/06/23 12:30:09:355
    JST] 0000009b SibMessage E
    [intjmsbus:CLUSTERNME.002-intjmsbus] CWSIS1501E:
    ??????????????? com.ibm.db2.jcc.am.BatchUpdateException:
    [jcc][t4][102][10040][3.69.76] ???????????
    ?????????????????????????????? 1
    ????????????
    getNextException()
    ??????????????????????????????????? ERRORCODE=-4229,
    SQLSTATE=null ??????????
    ----------
    
    The message store is a
    data store, not a file store. The error output to the Db2 side
    at the same time is as
    follows.
    ----------
    2020-06-23-12.30.09.343842+540
    I30299588E869 LEVEL: Error
    PID : 11220 TID : 47037747816192
    PROC : db2sysc 0
    INSTANCE: db2mam NODE : 000 DB : MAMDB
    APPHDL
    : 0-11627 APPID: 184.120.2.1.51500.200503103434
    AUTHID : DB2MAM
    HOSTNAME: HOSTNAME
    EDUID : 18483 EDUNAME: db2agent (MAMDB)
    0
    FUNCTION: DB2 UDB, relation data serv, sqlrr_array_input,
    probe:210
    DATA #1 : SQLCA, PD_DB2_TYPE_SQLCA, 136 bytes
    
    sqlcaid : SQLCA sqlcabc: 136 sqlcode: -911 sqlerrml: 1
    
    sqlerrmc: 2
    sqlerrp : SQLRI2CC
    sqlerrd : (1) 0x80100002 (2)
    0x00000002 (3) 0x00000000
    (4) 0x00000000 (5) 0xFFFFFE0C (6)
    0x00000000
    sqlwarn : (1) (2) (3) (4) (5) (6)
    (7) (8) (9)
    (10) (11)
    ----------
    
    After that, we received the following
    report from the Db2 team investigation.
    ----------
    The
    deadloack happens like as followings:
    Application A holding a
    row lock on IBMWASSIB000.SIB001 table, then request another row
    locks on the same table, which already held by B.
    Application B
    also holding a row lock on IBMWASSIB000.SIB001 table, then
    request another row locks on the same table, which already held
    by A.
    i.e, this deadlock is caused by a defect on the
    application A/B. So, the application have to be
    fixed.
    ----------
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Users of IBM WebSphere Application Server   *
    *                  who are running a SIB messaging engine      *
    *                  using a database as a message store         *
    ****************************************************************
    * PROBLEM DESCRIPTION: Message processing can stop and the     *
    *                      database can report a deadlock within   *
    *                      the SIB database tables.                *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When multiple threads are attempting to update message records
    in the datastore, a lock is held on to an updated record while
    an attempt is made to lock the next record to be updated. If
    multiple threads are updating records in different orders it
    is possible for a deadlock to occur.
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    PH29166

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-09-03

  • Closed date

    2021-05-25

  • Last modified date

    2021-05-25

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"850"}]

Document Information

Modified date:
26 May 2021