PM17521: CONTENTIONS IN COM.IBM.WPS.PE.PORTLETENTITY CACHE AFTER SERVANT RESTARTED CAUSING SLOW DOWN IN PERFORMANCE

Fixes are available

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 V6.1.0 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 PM17521 is currently targeted for inclusion in
Service Level (Fix Pack) 6.1.0.35 of WebSphere
Application Server V6.1

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
PM17521
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-06-30
Closed date
2010-07-19
Last modified date
2011-01-03

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

PM17530

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK62676
UP10/12/17 P F012

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":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
25 October 2021

Tips

PM17521: CONTENTIONS IN COM.IBM.WPS.PE.PORTLETENTITY CACHE AFTER SERVANT RESTARTED CAUSING SLOW DOWN IN PERFORMANCE

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R610 PSY UK62676

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.

Document Information

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