IBM Support

PI51508: REDUCE CONTENTION IN ABSTRACTOWBBEAN.EQUALS USE

Fixes are available

8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

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APAR status

  • Closed as program error.

Error description

  • Reported scenario where system experiences severe slowdown with
many threads contending with similar call stacks:


at java/util/Hashtable.get(Hashtable.java:502(Compiled Code))


at java/lang/Class.lookupCachedMethods(Class.java:3068(Compiled
Code))
at java/lang/Class.getDeclaredMethods(Class.java:909(Compiled
Code))
at javax/enterprise/util/AnnotationLiteral.run
(AnnotationLiteral.java:274(Compiled Code))
at java/security/AccessController.doPrivileged
(AccessController.java:364(Compiled Code))
at javax/enterprise/util/AnnotationLiteral.hashCode
(AnnotationLiteral.java:271(Compiled Code))
at java/util/HashMap.hash(HashMap.java:374(Compiled Code))
at java/util/HashMap.getEntry(HashMap.java:474(Compiled Code))
at java/util/HashMap.containsKey(HashMap.java:461(Compiled
Code))
at java/util/HashSet.contains(HashSet.java:213(Compiled Code))
at java/util/AbstractCollection.containsAll
(AbstractCollection.java:328(Compiled Code))
at java/util/AbstractSet.equals(AbstractSet.java:107(Compiled
Code))
at org/apache/webbeans/component/AbstractOwbBean.equals
(AbstractOwbBean.java:760(Compiled Code))
at java/util/concurrent/ConcurrentHashMapSegment.containsKey
(ConcurrentHashMap.java:460(Compiled Code))
at java/util/concurrent/ConcurrentHashMap.containsKey
(ConcurrentHashMap.java:905(Compiled Code))
at
org/apache/webbeans/context/AbstractContext.getCreationalContext
(AbstractContext.java:240(Compiled Code))
at
org/apache/webbeans/intercept/NormalScopedBeanInterceptorHandler
.
getContextualCreationalContext
(NormalScopedBeanInterceptorHandler.java:154(Compiled Code))
at
org/apache/webbeans/intercept/NormalScopedBeanInterceptorHandler
.
invoke(NormalScopedBeanInterceptorHandler.java:98(Compiled
Code))

Local fix

  • None identified

Problem summary

  • ****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server                                      *
*                  using Context Dependency Injection (CDI)    *
****************************************************************
* PROBLEM DESCRIPTION: Severe system slowdown due to many      *
*                      threads contending on calls to          *
*                      Class.lookupCachedMethods() from CDI.   *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
System experiences severe slowdown with
many threads contending with similar call stacks:
at java/util/Hashtable.get(Hashtable.java:502(Compiled Code))
at java/lang/Class.lookupCachedMethods(Class.java:3068(Compiled
Code))
at java/lang/Class.getDeclaredMethods(Class.java:909(Compiled
Code))
at javax/enterprise/util/AnnotationLiteral.run
(AnnotationLiteral.java:274(Compiled Code))
at java/security/AccessController.doPrivileged
(AccessController.java:364(Compiled Code))
at javax/enterprise/util/AnnotationLiteral.hashCode
(AnnotationLiteral.java:271(Compiled Code))
at java/util/HashMap.hash(HashMap.java:374(Compiled Code))
at java/util/HashMap.getEntry(HashMap.java:474(Compiled Code))
at java/util/HashMap.containsKey(HashMap.java:461(Compiled
Code))
at java/util/HashSet.contains(HashSet.java:213(Compiled Code))
at java/util/AbstractCollection.containsAll
(AbstractCollection.java:328(Compiled Code))
at java/util/AbstractSet.equals(AbstractSet.java:107(Compiled
Code))
at org/apache/webbeans/component/AbstractOwbBean.equals
(AbstractOwbBean.java:760(Compiled Code))
at java/util/concurrent/ConcurrentHashMapSegment.containsKey
(ConcurrentHashMap.java:460(Compiled Code))
at java/util/concurrent/ConcurrentHashMap.containsKey
(ConcurrentHashMap.java:905(Compiled Code))
at
org/apache/webbeans/context/AbstractContext.getCreationalContext
(AbstractContext.java:240(Compiled Code))
at
org/apache/webbeans/intercept/NormalScopedBeanInterceptorHandler
.
getContextualCreationalContext
(NormalScopedBeanInterceptorHandler.java:154(Compiled Code))
at
org/apache/webbeans/intercept/NormalScopedBeanInterceptorHandler
.
invoke(NormalScopedBeanInterceptorHandler.java:98(Compiled
Code))

Problem conclusion

  • Optimizations in comparison ordering in
org.apache.webbeans.component.AbstractOwbBean.equals reduces
the average cost of the equals() calculation, and optimizations
in org.apache.webbeans.context.AbstractContext reduces the
frequency that equals is called.

The fix for this APAR is currently targeted for inclusion in
fix packs 8.5.5.9 and 8.0.0.13.  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
    PI51508
    • 

  • Reported component name
    WEBS APP SERV N
    • 

  • Reported component ID
    5724H8800
    • 

  • Reported release
    850
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2015-10-29
    • 

  • Closed date
    2016-02-11
    • 

  • Last modified date
    2016-02-11
    • 





    

  • 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


    

  • R800  PSY
       UP
    • 

  • R850  PSY
       UP
    • 








      
              
                            

              

              [{"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","Line of Business":{"code":"LOB45","label":"Automation"}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            28 April 2022
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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