IBM Support

IT27920: LOCK-WAITS/DEADLOCKS ON SYSDATATYPES CATALOG TABLE DURING MODULEDEPLOYMENT

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APAR status

  • Closed as program error.

Error description

  • Lock-waits/deadlocks may be observed between the agent altering
    the module to update with new code , and the agents trying to
    execute the old module/procedure.
    
    Even though the module names are different, however the data
    types defined/used in the new and old code, have the same type
    name which causes this lock conflict between the agents.
    
    Here is the example command to alter the new module to publish
    the new code:
    
    
    ALTER MODULE "new-module-name" PUBLISH PROCEDURE "procedure
    name"....
    
    The application doing alter module had several locks/deadlock on
    sysdatatypes catalog table.The locks were X locks.
    
    If the procedure name used in this new module, is also the same
    as the one being used in old module, this may also cause lock
    contention on  the catalog cache.
    
    Hence, to avoid the lock contention on procschema lookup in
    catalog cache, please use different procedure name.
    
    This APAR fix will make enhancements for the locking on
    SYSDATATYPES catalog table and hence avoid the lock/deadlock
    contention.
    

Local fix

  • To avoid lock contention on catalog cache, use different
    procedure name in the new modules as well to avoid locking on
    catalog cache.
    

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

    IT27920

  • 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

    2019-01-29

  • Closed date

    2020-01-16

  • Last modified date

    2020-01-16

  • 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

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • RB10 PSN

       UP

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Document Information

Modified date:
16 January 2020