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PH40496: PH40496:Deadlock in APC APCXDCpuUtilizationBasedPredictor during startup

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APAR status

  • Closed as program error.

Error description

  • PH40496:Deadlock in APC APCXDCpuUtilizationBasedPredictor
during startup

Local fix

  • N/A

Problem summary

  • ****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server WAS ND edition- Virtual              *
*                  Enterprise/IM Component                     *
****************************************************************
* PROBLEM DESCRIPTION: Deadlock in APC                         *
*                      APCXDCpuUtilizationBasedPredictor       *
*                      during startup                          *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
There is a potentially a thread race condition during deployment
manager startup may lead to a deadlock if APC controller is
active on deployment manager. Below is the stack trace of the
deadlock

Java Stack
at
com/ibm/apc/xd/demand/predictors/cpu/APCXDCpuUtilizationBasedPre
dictor.start(APCXDCpuUtilizationBasedPredictor.java:120)			 ----
WAITING ON TREE
at
com/ibm/apc/xd/demand/predictors/combined/APCXDCombinedPredictor
.useCPUBasedPredictor(APCXDCombinedPredictor.java:192)
at
com/ibm/apc/xd/demand/predictors/combined/APCXDCombinedPredictor
Listener.useCPUBasedPredictor(APCXDCombinedPredictorListener.jav
a:154) 	--- cellKeyToPredictor OBTAINED HERE IS ---
at
com/ibm/apc/xd/demand/predictors/combined/APCXDCombinedPredictor
Listener.createPredictors_thread(APCXDCombinedPredictorListener.
java:126)
at
com/ibm/apc/xd/demand/predictors/combined/APCXDCombinedPredictor
Listener$1.run(APCXDCombinedPredictorListener.java:117)
at
java/util/concurrent/ThreadPoolExecutor.runWorker(ThreadPoolExec
utor.java:1160(Compiled Code))
at
java/util/concurrent/ThreadPoolExecutor$Worker.run(ThreadPoolExe
cutor.java:635)
at java/lang/Thread.run(Thread.java:822)

Problem conclusion

  • Made code changes to address the thread race condition during
startup to prevent potential deadlock

The fix for this APAR is currently targeted for inclusion in fix
packs 8.5.5.21 and 9.0.5.11.  Please refer to the Recommended
Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    PH40496
    • 

  • Reported component name
    IBM HTTP SERVER
    • 

  • Reported component ID
    5724J0801
    • 

  • Reported release
    850
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2021-09-09
    • 

  • Closed date
    2021-11-16
    • 

  • Last modified date
    2021-11-16
    • 





    

  • 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
    WEBS APP SERV N
    • 

  • Fixed component ID
    5724H8800
    • 



Applicable component levels


    








      
              
                            

              

              [{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.5"}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            17 November 2021
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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