IBM Support

IZ35534: LOAD PERFORMANCE PROBLEM ON WINDOWS IF THE CPU PARALLELISM APPLIED IS GREATER THAN 1

Fixes are available

DB2 Version 9.1 Fix Pack 9  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 10  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When load cpu_parallelism > 1 is applied on load on the Windows
platform ( which is the default with a sufficiently sized
UTIL_HEAP_SZ and a multi CPU machine ), it is possible that
the load may not have optimal performance.

This is due to a particular spinlock algorithm applied by the
formatter processes in a load that may suffer from thread
starvation by the Windows process scheduler.

The problem can be diagnosed with the output of a db2trc
-perfcount -t data collection, showing excessive wait times in
the sqlulPutBuffer function call.

Local fix

  • In some cases the Windows scheduler behaves differently when
other single process/ multi threaded applications e.g. the
javaw.exe process started by the Control Center is started. This
then appears to avoid the thread starvation in the load agents.

Problem summary

  • ****************************************************************
* USERS AFFECTED:                                              *
* DB2 on Windows users                                         *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* Load Performance may not be optimal. Lazy system             *
* performanceis observed i.e. no high cpu, no high I/O rates   *
****************************************************************
* RECOMMENDATION:                                              *
* Upgrade the database server to DB2 V9.1 Fix Pack 9           *
****************************************************************

Problem conclusion

  • This problem was first fixed in DB2 V9.1 Fix Pack 9

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IZ35534
    • 

  • Reported component name
    DB2 UDB ESE SOL
    • 

  • Reported component ID
    5765F4102
    • 

  • Reported release
    910
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2008-10-23
    • 

  • Closed date
    2010-04-22
    • 

  • Last modified date
    2010-04-22
    • 





    

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

    
IZ25650
    

    • 

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

    • 



Fix information


    

  • Fixed component name
    DB2 UDB ESE SOL
    • 

  • Fixed component ID
    5765F4102
    • 



Applicable component levels


    

  • R910  PSN
       UP
    • 








      
              
                            

              

              [{"Line of Business":{"code":"LOB10","label":"Data and AI"},"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":"910"}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            03 October 2021
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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