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IC78310: DB2 WLM MAY NOT TERMINATE TRANSACTION ON UOW TOTAL TIME THRESHOL D VIOLATION IF APPLICATION IS WAITING FOR RESPONSE FROM CLIENT.

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APAR status

  • Closed as program error.

Error description

  • When WLM UOW total time threshold is defined, it is expected
    that current transaction will be terminated  as soon as
    threshold time limit is reached. Agent working for the
    application is responsible for checking if any of WLM threshold
    limits are violated by the application.
    
    However if coordinator agent for the application is waiting for
    a new request to arrive from the fron-tend client, it is not
    checking if UOW total time threshold limit is reached.
    Therefore, in some cases, when we have "lazy client application"
    it may be possible for a single transaction to last longer then
    WLM limit defined.
    
    To reproduce:
    
    1. Create threshold:
    
    CREATE THRESHOLD UOW1min FOR DATABASE ACTIVITIES
       ENFORCEMENT DATABASE
       WHEN UOWTOTALTIME > 1 MINUTE STOP EXECUTION;
    
    ALTER THRESHOLD UOW1MIN ENABLE ;
    
    2. Perform some activity and leave transaction open:
    
    $ db2 connect to sample
    $ db2 +c "create table t1 (c1 integer)"
    $ db2 +c "insert into t1 values (1)"
    
    $ sleep 180
    
    Leave this tx open - do not run any other db2 commands from this
    window.
    
    3. From a different window, check if transaction is still open,
    after 3 minutes:
    
    $ db2 "select count(*) from t1 with UR"
    
    You should see the data you inserted, rollback hasn't been done.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All WLM users                                                *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * DB2 WLM may not terminate transaction on UOW total time      *
    * threshold violation if application is waiting for response   *
    * from the client.                                             *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Please upgrade to the Fix pack containing the Fix once the   *
    * FIX is available.                                            *
    ****************************************************************
    

Problem conclusion

  • Problem to be addressed: 9.7 Fixpack 6 and later.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IC78310

  • 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

    2011-08-24

  • Closed date

    2012-06-05

  • Last modified date

    2012-06-05

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

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

    IC84401

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

  • R970 PSY

       UP



Document information

More support for: DB2 for Linux, UNIX and Windows

Software version: 9.7

Reference #: IC78310

Modified date: 05 June 2012