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IT23360: DB2READLOG API CAN HANG IN PURESCALE.

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APAR status

  • Closed as fixed if next.

Error description

  • The db2Read API can hang when it is executed concurrently on
    multiple members in pureScale environment.
    In this situation, other EDU updating log records also can
    hang.
    
    Example of stack traces in this problem - there will be one
    stack with UpgradeLock and another with sqloXlatchConflict:
    
    <StackTrace>
    -------Frame------ ------Function + Offset------
    0x0900000000112F14 thread_wait + 0x94
    0x090000000D8EC6E8 sqloWaitEDUWaitPost + 0x2D8
    0x090000000C80F918
    sqlplWaitOnWP__FCP9sqeBsuEduCP14SQLP_LOCK_INFOCP8SQLP_LRBCP15SQL
    P_LTRN_CHAINCbN25 + 0x273C
    0x090000000CCF1F14
    sqlplMakeNewRequestSD__FP9sqeBsuEduP14SQLP_LOCK_INFOP11SQLP_TENT
    RYRP8SQLP_LRBP8SQLP_LRBP15SQLP_LTRN_CHAINbT7CbN29 + 0x160C
    0x090000000C870008
    sqlpUpgradeLock__FP9sqeBsuEduP14SQLP_LOCK_INFO + 0xE7C
    0x09000000098229FC
    sqlpgReadStartUse__FP9SQLP_DBCBP9sqeBsuEduCUiCUsCUlPb + 0x640
    0x090000000E40D74C
    sqlplfrFMOpenLog__FP12SQLPLFR_DBCBUiP21SQLPLFR_REQ_SCAN_NEXTUlPU
    lPP9SQLP_LECB + 0xFE8
    0x090000000E41D0A8
    sqlplfrFMReadLog__FP12SQLPLFR_DBCBP21SQLPLFR_REQ_SCAN_NEXTP17SQL
    PLFR_SCAN_DATA + 0x42AC
    0x090000000DEB492C RunEDU__9sqpLfrEduFv + 0x23BC
    0x090000000DEB0264 RunEDU__9sqpLfrEduFv + 0x364
    0x090000000DEAFFD0 RunEDU__9sqpLfrEduFv + 0xD0
    0x090000000D66B1FC EDUDriver__9sqzEDUObjFv + 0x3F0
    0x090000000C3C0DCC sqloEDUEntry + 0x390
    </StackTrace>
    
    
    <StackTrace>
    -------Frame------ ------Function + Offset------
    0x090000000C8137E4 sqloXlatchConflict + 0x540
    0x09000000098235D4
    sqlpgReadUpdateUseReader__FP9SQLP_DBCBP9sqeBsuEduCUiCUs + 0x63C
    0x090000000E40DD78
    sqlplfrFMOpenLog__FP12SQLPLFR_DBCBUiP21SQLPLFR_REQ_SCAN_NEXTUlPU
    lPP9SQLP_LECB + 0x1614
    0x090000000E41D0A8
    sqlplfrFMReadLog__FP12SQLPLFR_DBCBP21SQLPLFR_REQ_SCAN_NEXTP17SQL
    PLFR_SCAN_DATA + 0x42AC
    0x090000000DEB492C RunEDU__9sqpLfrEduFv + 0x23BC
    0x090000000DEB0264 RunEDU__9sqpLfrEduFv + 0x364
    0x090000000DEAFFD0 RunEDU__9sqpLfrEduFv + 0xD0
    0x090000000D66B1FC EDUDriver__9sqzEDUObjFv + 0x3F0
    0x090000000C3C0DCC sqloEDUEntry + 0x390
    </StackTrace>
    

Local fix

  • Execute db2ReadLog API only on one member.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Purescale with more than 3 members.                          *
    * Running readlog application from more than 3 members in      *
    * parallel.                                                    *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Execute db2ReadLog API only on one to two member(s).         *
    *                                                              *
    * Update to fix pack 3.                                        *
    ****************************************************************
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    IT23360

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED FIN

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-12-01

  • Closed date

    2018-03-15

  • Last modified date

    2018-03-15

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

    IT22567

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

Fix information

Applicable component levels

  • RB10 PSN

       UP

  • RB10 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
15 March 2018