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PK69093: HANG IN APPLICATION CALLS TO STATEFUL SESSION JAVAJBEANS WHEN ACTIVATION AND PASSIVATION OCCUR CONCURRENTLY

Fixes are available

Java SDK 1.5 SR8 Cumulative Fix for WebSphere Application Server
Java SDK 1.5 SR10 Cumulative Fix for WebSphere Application Server
6.1.0.31: Java SDK 1.5 SR11 FP1 Cumulative Fix for WebSphere Application Server
6.1.0.33: Java SDK 1.5 SR12 FP1 Cumulative Fix for WebSphere
6.1.0.29: Java SDK 1.5 SR11 Cumulative Fix for WebSphere Application Server
6.1.0.35: Java SDK 1.5 SR12 FP2 Cumulative Fix for WebSphere
6.1.0.37: Java SDK 1.5 SR12 FP3 Cumulative Fix for WebSphere
6.1.0.39: Java SDK 1.5 SR12 FP4 Cumulative Fix for WebSphere Application Server
6.1.0.41: Java SDK 1.5 SR12 FP5 Cumulative Fix for WebSphere Application Server
6.1.0.43: Java SDK 1.5 SR13 Cumulative Fix for WebSphere Application Server
6.1.0.45: Java SDK 1.5 SR14 Cumulative Fix for WebSphere Application Server
6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The primary symptom of this problem is that calls to an
Enterprise JavaBean do not complete.  This problem only occurs
for Enterprise JavaBeans that are persisted, it is occurring
for Stateful Session Enterprise JavaBeans.  The problem occurs
when the same Enterprise JavaBean instance is being
passivated and activated at the same time.
A javacore of the WebSphere Application Server process shows
a deadlock similar to this one.
1LKDEADLOCK    Deadlock detected !!!
NULL           ---------------------
NULL
2LKDEADLOCKTHR  Thread "WebContainer : 8" (0x00002AAB38BA8700)
3LKDEADLOCKWTR    is waiting for:
4LKDEADLOCKMON      sys_mon_t:0x00002AAB344142C0 infl_mon_t:
0x00002AAB34414340:
4LKDEADLOCKOBJ
java/lang/Object@00002AAAB7417880/00002AAAB7417898:
3LKDEADLOCKOWN    which is owned by:
2LKDEADLOCKTHR  Thread "Deferrable Alarm : 3"
(0x00000000024F6C00)
3LKDEADLOCKWTR    which is waiting for:
4LKDEADLOCKMON      sys_mon_t:0x0000000001961618 infl_mon_t:
0x0000000001961698:
4LKDEADLOCKOBJ
com/ibm/ejs/container/passivator/StatefulPassivator@00002AAAB73F
9240/00002AAAB73F9258:
3LKDEADLOCKOWN    which is owned by:
2LKDEADLOCKTHR  Thread "WebContainer : 8" (0x00002AAB38BA8700)
.
3XMTHREADINFO      "Deferrable Alarm : 3"
(TID:0x00000000024F6C00, sys_thread_t:0x00000000024EAB68,
state:B, native ID:0x0000000000000293) prio=5
4XESTACKTRACE          at
com/ibm/ejs/container/StatefulBeanO.passivate(StatefulBeanO.java
:583(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/activator/StatefulSessionActivationStrateg
y.atDiscard(StatefulSessionActivationStrategy.java:484(Compiled
Code))
4XESTACKTRACE          at
com/ibm/ejs/container/activator/Activator.discardObject(Activato
r.java:822(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/util/cache/Cache.evictObject(Cache.java:1034(Compile
d Code))
4XESTACKTRACE          at
com/ibm/ejs/util/cache/BackgroundLruEvictionStrategy.sweep(Backg
roundLruEvictionStrategy.java:527(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/util/cache/BackgroundLruEvictionStrategy.alarm(Backg
roundLruEvictionStrategy.java:420(Compiled Code))
.
3XMTHREADINFO      "WebContainer : 8" (TID:0x00002AAB38BA8700,
sys_thread_t:0x00002AAB39E681C8, state:B, native
ID:0x00000000000003BD) prio=5
4XESTACKTRACE          at
com/ibm/ejs/container/activator/SingletonActivationStrategy.atGe
t(SingletonActivationStrategy.java:329(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/activator/Activator.getBean(Activator.java
:662(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/EJSHome.getBean_Common(EJSHome.java:2447(C
ompiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/EJSHome.getBean(EJSHome.java:2355(Compiled
Code))
4XESTACKTRACE          at
com/ibm/global/order/cart/EJSBMPglobal_CartHomeBean_dcc4
719b.findByPrimaryKey(Bytecode PC:2(Compiled Code))
4XESTACKTRACE          at
com/ibm/global/order/cart/EJSRemoteBMPglobal_CartHome_dc
c4719b.findByPrimaryKey(Bytecode PC:56(Compiled Code))
4XESTACKTRACE          at
com/ibm/global/order/cart/_CartHome_Stub.findByPrimaryKey
(_CartHome_Stub.java:292(Compiled Code))
4XESTACKTRACE          at
com/ibm/global/util/factory/EJBServiceFactory.findCart(B
ytecode PC:26(Compiled Code))
4XESTACKTRACE          at
com/ibm/global/order/cart/GlobalWebCart.init(Bytecode
PC:26(Compiled Code))
4XESTACKTRACE          at
com/ibm/global/order/cart/GlobalWebCart.readExternal(Byt
ecode PC:18)
4XESTACKTRACE          at
java/io/ObjectInputStream.readExternalData(ObjectInputStream.jav
a:1768(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readOrdinaryObject(ObjectInputStream.j
ava:1726(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readObject0(ObjectInputStream.java:131
4(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.defaultReadFields(ObjectInputStream.ja
va:1927(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readSerialData(ObjectInputStream.java:
1851(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readOrdinaryObject(ObjectInputStream.j
ava:1728(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readObject0(ObjectInputStream.java:131
4(Compiled Code))
4XESTACKTRACE          at
java/io/ObjectInputStream.readObject(ObjectInputStream.java:354(
Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/passivator/StatefulPassivator.activate(Sta
tefulPassivator.java:325(Compiled Code))
4XESTACKTRACE          at
com/ibm/ejs/container/StatefulBeanO.activate(StatefulBeanO.java:
498)
4XESTACKTRACE          at
com/ibm/ejs/container/activator/StatefulSessionActivationStrateg
y.atActivate(StatefulSessionActivationStrategy.java:282(Compiled
Code))
4XESTACKTRACE          at
com/ibm/ejs/container/activator/Activator.activateBean(Activator
.java:597(Compiled Code))

Local fix

  • One possible workaround is increase the EJB cache to reduce the
frequency of EJB passivation.  But this increases the java heap
required for the EJB cache.
.
Change the ejbPassivate to store the BMP primary key in an
instance variable during ejbPassivate, and then do the
findByPrimaryKey for it during ejbActivate, that would avoid the
problem.

Problem summary

  • ****************************************************************
* USERS AFFECTED:  All users of the IBM?  WebSphere?           *
*                  Application Server V6.1.0 and               *
*                  the use of Stateful Session Enterprise      *
*                  JavaBean (stateful session bean for short). *
****************************************************************
* PROBLEM DESCRIPTION: Deadlock in the Enterprise JavaBeans    *
*                      Container while passivating and         *
*                      concurrently activating a stateful      *
*                      session bean.                           *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The scenario to hit this issue was as follows:

One stateful session bean is being passivated while at the
same time another stateful session bean is being activated.
It is acceptable for beans to be passivated and activated
at the same time, and is accounted for by the Enterprise
JavaBeans Container.  However, in the scenario
there is a very narrow situation which caused this scenario to
deadlock.  That is, during the activation of the stateful
session bean, the bean being activated made a call to
another bean.  Part of the Enterprise JavaBeans Container
synchronization locks for the requested bean were in use
by the thread performing the passivation of the other stateful
session bean.  Therefore, the thread performing the activate
had to wait for the given lock.  Meanwhile, the thread
performing the passivation eventually needed a lock held by
the thread performing the activation, thus the deadlock.
The key part of this scenario is where the user made a call to
another bean during the activation of their stateful session
bean, and the thread associated with the requested bean in turn
happened to need a lock held by a thread performing the
passivation of their stateful session bean.  This is not a
typical scenario and is very hard to hit.
It is acceptable for the user to make a call to
another bean from within the activation of their stateful
session bean and in most cases will never result in a
deadlock.

Problem conclusion

  • Code has been added to account for the deadlock caused
by the timing issues of the scenario described above.

The fix for this APAR is currently targeted for inclusion in
Service Level (Fix Pack) 6.1.0.21 of
WebSphere Application Server version 6.1.0.
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
    PK69093
    • 

  • Reported component name
    WEBS APP SERV N
    • 

  • Reported component ID
    5724H8800
    • 

  • Reported release
    61A
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2008-07-15
    • 

  • Closed date
    2008-09-09
    • 

  • Last modified date
    2008-09-09
    • 





    

  • 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


    

  • R61A  PSY
       UP
    • 

  • R61H  PSY
       UP
    • 

  • R61I  PSY
       UP
    • 

  • R61P  PSY
       UP
    • 

  • R61S  PSY
       UP
    • 

  • R61W  PSY
       UP
    • 

  • R61Z  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":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]
              

                                                                    

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            29 December 2021
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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