IBM Support

PM17530: CONTENTIONS IN COM.IBM.WPS.PE.PORTLETENTITY CACHE AFTER SERVANT RESTARTED CAUSING SLOW DOWN IN PERFORMANCE

A fix is available

Obtain the fix for this APAR.

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Contentions in com.ibm.wps.pe.portletentity cache after Servant
restarted causing slow down in performance.

In javacores, threads look like this:

"WebSphere:ORB.thread.pool t=0077a088" (TID:0x0000000B7786D800,
sys_thread_t:0x0
at com/ibm/ws/cache/Cache.freeLruEntry(Cache.java:1845(
    Compiled Code)).
at com/ibm/ws/cache/Cache.getFreeLruEntry(Cache.java:1801(
    Compiled Code)).
at com/ibm/ws/cache/Cache.getFreeLruEntry(Cache.java:1802(
    Compiled Code)).
at com/ibm/ws/cache/Cache._syncSetValue(Cache.java:980(
    Compiled Code)).
at com/ibm/ws/cache/Cache.invalidateAndSet(Cache.java:1136(
    Compiled Code)).
at com/ibm/ws/cache/DistributedObjectCacheAdapter.common_put(
    DistributedObje
at com/ibm/ws/cache/DistributedMapImpl.put(
    DistributedMapImpl.java:78(Compil
at com/ibm/wps/services/cache/DistributedMapCache.put(
    DistributedMapCache.ja
at com/ibm/wps/services/cache/TransactionAwareCache.put(
    TransactionAwareCach
at com/ibm/wps/services/registry/PortletEntityManagerImpl.
    getScopedPortletEn
at com/ibm/wps/composition/elements/Control.
    getScopedPortletEntity(Control.j
at com/ibm/wps/pe/pc/waspc/services/persistence/
    WPPreferencesHierarchyImpl.s
at com/ibm/wps/pe/pc/waspc/services/persistence/
    WPPreferencesHierarchyImpl.i
at com/ibm/wps/pe/pc/waspc/services/persistence/
    WaspcPersistenceProviderImpl
at com/ibm/ws/portletcontainer/om/window/impl/
    PortletWindowImpl.loadProvider
at com/ibm/ws/portletcontainer/om/window/impl/
    PortletWindowImpl.getPreferenc
at com/ibm/ws/portletcontainer/core/impl/
    PortletPreferencesImpl.<init>(Portl
at com/ibm/ws/portletcontainer/factory/impl/
    PortletPreferencesFactoryImpl.ge
at com/ibm/ws/portletcontainer/factory/PortletObjectAccess.
    getPortletPrefere
at com/ibm/ws/portletcontainer/core/impl/PortletRequestImpl.
    getPreferences(P

another symptom easier to detect is this:
cust will see a lot of threads waiting for
com/ibm/ws/cache/Cache object

sys_mon_t:0x0000000C5BF8C990 infl_mon_t: 0x0000000C5BF8CA10:.
  com/ibm/ws/cache/Cache@000000082F7D3618/000000082F7D3630:
owner "WebSphere:ORB
Waiting to enter:.
"WebSphere:ORB.thread.pool t=007b2510" (0x0000000B7785A900).
"WebSphere:ORB.thread.pool t=007a8cf0" (0x0000000B7785E400).
"WebSphere:ORB.thread.pool t=007a8e88" (0x0000000B7785EB00).
"WebSphere:ORB.thread.pool t=007b2378" (0x0000000B77860400).
"WebSphere:ORB.thread.pool t=007a8b58" (0x0000000B77860B00).
"WebSphere:ORB.thread.pool t=00798088" (0x0000000B77862500).
"WebSphere:ORB.thread.pool t=00790088" (0x0000000B77862C00).
"WebSphere:ORB.thread.pool t=00792088" (0x0000000B77864500).
"WebSphere:ORB.thread.pool t=0078c088" (0x0000000B77864C00).
"WebSphere:ORB.thread.pool t=00784088" (0x0000000B77868700).
"WebSphere:ORB.thread.pool t=00788088" (0x0000000B77868E00).
"WebSphere:ORB.thread.pool t=00786088" (0x0000000B7786A700).
"WebSphere:ORB.thread.pool t=00796088" (0x0000000B7786AE00).
"WebSphere:ORB.thread.pool t=0077e088" (0x0000000B7786DF00).
"WebSphere:ORB.thread.pool t=00770088" (0x0000000B77871900).
"WebSphere:ORB.thread.pool t=00776088" (0x0000000B77872000).
"WebSphere:ORB.thread.pool t=00774088" (0x0000000B77872A00).
"WebSphere:ORB.thread.pool t=0076c088" (0x0000000B77873100).
"WebSphere:ORB.thread.pool t=00768088" (0x0000000B77875B00).
"WebSphere:ORB.thread.pool t=00780088" (0x0000000B77876200).
"WebSphere:ORB.thread.pool t=0075c088" (0x0000000B77879C00).
"WebSphere:ORB.thread.pool t=00760088" (0x0000000B7787A300).
"WebSphere:ORB.thread.pool t=00756088" (0x0000000B7787BD00).
"WebSphere:ORB.thread.pool t=00748088" (0x0000000B7787C400).
"WebSphere:ORB.thread.pool t=00746088" (0x0000000B7787FE00).
"WebSphere:ORB.thread.pool t=00758088" (0x0000000B77880500).
"WebSphere:ORB.thread.pool t=00752088" (0x0000000B77882F00).
"WebSphere:ORB.thread.pool t=0073e088" (0x0000000B77883600).
"WebSphere:ORB.thread.pool t=00766088" (0x0000000B77884F00).
"WebSphere:ORB.thread.pool t=00736088" (0x0000000B77885600).
"WebSphere:ORB.thread.pool t=00738088" (0x0000000B7788A100).
"WebSphere:ORB.thread.pool t=00734088" (0x0000000B7788A800).
"WebSphere:ORB.thread.pool t=00730088" (0x0000000B7788C200).
"WebSphere:ORB.thread.pool t=0074c088" (0x0000000B7788C900).
"WebSphere:ORB.thread.pool t=00726088" (0x0000000B7788F300).

Local fix

  • 



Problem summary


    

  • ****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V7.0 using dynacache.                *
****************************************************************
* PROBLEM DESCRIPTION: A performance degradation is observed   *
*                      when a cache becomes full.  This may    *
*                      coincide with the restart of a          *
*                      servant region.                         *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When a cache becomes full the least recently used (LRU)
algorithm is used to evict a cache entry to make room for a
new entry.  During the LRU process the cache is locked and
other threads are held waiting.  When the LRU process executes
a long time other threads needing access to the cache do not
run and a performance issue is observed.

    



Problem conclusion


    

  • The LRU algorithim has been modified to improve performance.

APAR PM17530 is currently targeted for inclusion in
Service Level (Fix Pack) 7.0.0.13 of WebSphere
Application Server

Please refer to URL:
//www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
for Fix Pack availability.

    



Temporary fix


    

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    PM17530
    • 

  • Reported component name
    WEBSPHERE FOR Z
    • 

  • Reported component ID
    5655I3500
    • 

  • Reported release
    700
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2010-06-30
    • 

  • Closed date
    2010-07-19
    • 

  • Last modified date
    2010-11-02
    • 





    

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

    
PM17521
    

    • 

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

    • 



Fix information


    

  • Fixed component name
    WEBSPHERE FOR Z
    • 

  • Fixed component ID
    5655I3500
    • 



Applicable component levels


    

  • R700  PSY  UK61146
       UP10/10/21  P  F010
    • 



Fix is available


    

  • Select the PTF appropriate for your component level.
You will be required to sign in. Distribution on physical
media is not available in all countries.
    








      
              
                            

              

              [{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Edition":"","Line of Business":{"code":"LOB45","label":"Automation"}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            10 February 2022
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
Page Feedback