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IC71571: GET SNAPSHOT SEGMENTATION FAULT WHILE COLLECTING LOCK INFORMATION IN SQLPM_WRITE_LOCKS()

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When a Get Snapshot (or equivalent snapshot table function) is
    executed, in rare scenarios when lock information is being
    collected, and locks are being manipulated by other
    applications, or other applications are performing
    connect/connect-reset operations, a segmentation violation trap
    is possible.  The stack trace will contain sqlpm_write_locks()
    as the violating function, like this example:
    
    sqlpm_write_locks
    
    sqlpm_write_appl_locks
    
    sqm_snap_appl_locks
    
    sqm_snap_db_locks
    
    sqlmonssagnt
    
    [...]
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * This is a timing issue possibly produced when a get Snapshot *
    * agent is context-switched out just before it acquires        *
    * internal latch for transaction information, an application   *
    * switched in releases it's transaction (connect reset) and    *
    * when get Snapshot agent is switched back in, the internal    *
    * structures that it is pointing to have been already          *
    * released.                                                    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 Version 9.7 and Fix Pack xx                   *
    ****************************************************************
    

Problem conclusion

  • Problem was first fixed in DB2 Version 9.7 and Fix Pack xx
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC71571

  • 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

    2010-09-29

  • Closed date

    2011-05-03

  • Last modified date

    2011-05-03

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

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

    IC71574

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSY

       UP

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Document Information

Modified date:
03 May 2011