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IT30358: APPLICATION CONNECTIONS / NO CONNECTIONS ARE FORCED OFF INSTEAD OF A SPECIFIC LOW PRIORITY LOCK HOLDING SYSTEM APPLICATION

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APAR status

  • Closed as program error.

Error description

  • ** THIS APAR APPLIES ONLY TO Db2 Multi Partition scenario **
    
    Legitimate application / no connections can sometimes be forced
    off
    inadvertently when trying to force off system application
    connections holding low priority locks e.g. ADC ( db2adcbld ) or
    
    AutoGroom( db2abpgroom ) or Automatic runstats.
    The messages in the diag log will look like ( only if db2set
    DB2_FORCE_DIAGS=TRUE is set ):
    
    Application gets this error:
    ------------------------------
    
    SQL30081N  A communication error has been detected.
    Communication protocol
    being used: "TCP/IP".  Communication API being used: "SOCKETS".
    Location
    where the error was detected: "X.X.X.X".  Communication
    function
    detecting the error: "send".  Protocol specific error code(s):
    "32", "*", "0".
    SQLSTATE=08001
    
    The application connection which initiates the force:
    ----------------------------------------------------------
    
    2019-09-14-17.31.25.392889+120 I10679429E2907        LEVEL: Info
    PID     : 48633                TID : 47364194690816  PROC :
    db2sysc 0
    INSTANCE: db2inst1             NODE : 000            DB   :
    BLUDB
    APPHDL  : 25-45466             APPID:
    X.X.X.X.36840.190914153109
    AUTHID  : BLUADMIN             HOSTNAME: MYHOST1
    EDUID   : 41563                EDUNAME: db2agntp (BLUDB) 0
    FUNCTION: DB2 UDB, lock manager, sqlplWaitOnWP, probe:1370
    DATA #1 : <preformatted>
    Forcing application following information
    Workstation Location: elaawme2ba05
    Application Name    : DB2APP
    Application ID      : *NXX.DB2.190914153122
    Tablespace ID       : 0
    Object ID           : 5
    CALLSTCK: (Static functions may not be resolved correctly, as
    they are resolved to the nearest symbol)
      [0] 0x00002AEFE16C3F4D pdLogPrintf + 0x8D
      [1] 0x00002AEFE8BB1E9C
    _Z32sqlpDumpForceConflictingAppDiagsP12SQLZ_APP_HDLiiP14SQLP_LOC
    K_INFOb + 0x26C
      [2] 0x00002AEFE8BA0244
    _Z13sqlplWaitOnWPP9sqeBsuEduP14SQLP_LOCK_INFOP8SQLP_LRBP15SQLP_L
    TRN_CHAINbbb + 0x3014
      [3] 0x00002AEFE8B95B19
    _Z24sqlplMakeNewRequestNonSDP9sqeBsuEduP14SQLP_LOCK_INFOP11SQLP_
    TENTRYP8SQLP_LRBS6_P15SQLP_LTRN_CHAINbbb + 0x899
      [4] 0x00002AEFE89DA0FB _Z7sqlplrqP9sqeBsuEduP14SQLP_LOCK_INFO
    + 0xEDB
    
    The force received on the node where the system application is
    running (when everything is forced off):
    ----------------------------------------------------------------
    ----------------
    2019-09-14-17.31.25.604271+120 I16088052E1427        LEVEL:
    Warning
    PID     : 110145               TID : 47390635583232  PROC :
    db2sysc 40
    INSTANCE: db2inst1             NODE : 040
    HOSTNAME: MYHOST1
    EDUID   : 64                   EDUNAME: db2pdbc 40
    FUNCTION: DB2 UDB, base sys utilities,
    sqeAppServices::ForceAllApplications, probe:100
    DATA #1 : <preformatted>
    Forcing application with the following information
    Workstation Location: MYHOST1
    Application Name    : pmdtm
    Application ID      : X.X.X.X.52105.190914150518
    Application Handle  : 40-44651
    CALLSTCK: (Static functions may not be resolved correctly, as
    they are resolved to the nearest symbol)
      [0] 0x00002B19D5EE7F4D pdLogPrintf + 0x8D
      [1] 0x00002B19DB10A885
    _ZN14sqeAppServices20ForceAllApplicationsEP14sqeApplicationiiP16
    sqeLocalDatabaseiiP12sqzDataChainI19SQLE_COORDINATOR_CB16sqzCha
    + 0x285
      [2] 0x00002B19DB10A29E
    _ZN14sqeAppServices17ForceApplicationsEP14sqeApplicationiP12SQLZ
    _APP_HDLiiii + 0x15E
      [3] 0x00002B19DAFB2BB9
    _Z15sqleForceAgentsiiP12SQLZ_APP_HDLP5sqlcaiii + 0x159
      [4] 0x00002B19DAFD3E21
    _Z23sqlePdbSyscProcessForceP23SQLKD_RQST_REPLY_FORMAT + 0x121
      [5] 0x00002B19DB0588D2 _ZN22sqePdbSystemController6RunEDUEv +
    0x302
      [6] 0x00002B19DEB09BBE _ZN9sqzEDUObj9EDUDriverEv + 0x1BE
      [7] 0x00002B19DCF62F8A sqloEDUEntry + 0x57A
      [8] 0x00002B19D36D6DD5 /lib64/libpthread.so.0 + 0x7DD5
      [9] 0x00002B19E69DB02D clone + 0x6D
    
    If nothing is forced off the following is observed
    ----------------------------------------------------------------
    ----------------
    2019-09-23-15.33.01.970310-240 I1501029E471          LEVEL:
    Severe
    PID     : 7247                 TID : 139864200701696 PROC :
    db2sysc 0
    INSTANCE: db2inst1              NODE : 000
    HOSTNAME: MYHOST1
    EDUID   : 36                   EDUNAME: db2pdbc 0
    FUNCTION: DB2 UDB, base sys utilities,
    sqeAppServices::ForceSpecificApplications, probe:5
    MESSAGE : Invalid force agent ID:
    DATA #1 : Hexdump, 4 bytes
    0x00007F34ABFFD23C : 1600 0000
    ....
    
    
    Pls note the intention was to remove only the system application
    ( in this case the groom connection ) but it issues a force
    application all on the node where the groom connection had
    connected to which in turn causes the TCP/IP error for the
    legitimate application connection. In our second example the
    wrong application handle was sent, so nothing gets forced off.
    

Local fix

  • Local workaround:
    -----------------------
    
    db2 connect to <dbname>
    db2 update db cfg using MON_RTN_DATA none
    db2 terminate
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher                *
    ****************************************************************
    

Problem conclusion

  • First fixed in Db2 11.1 Mod 4 Fixpack 5
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT30358

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-09-23

  • Closed date

    2020-01-20

  • Last modified date

    2022-04-03

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

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

    IT32652

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RB10 PSN

       UP

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSEPGG","label":"DB2 for Linux- UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
03 May 2022