PK97310: LOCKING CONTENTION ON COMPOUNDCLASSLOADER DUE TO JAX-RPC WEB SERVICE RUNTIME CONFIGURATION

Fixes are available

APAR status

Closed as program error.

Error description

If a customer has a large number of threads making
JAX-RPC web service calls, a locking contention may occur.

A javacore file will indicate that the thread is waiting for a
CompoundClassLoader object.  Here is an example from a javacore
file:

2LKMONINUSE      sys_mon_t:0x37FF5680 infl_mon_t: 0x37FF56A8:
3LKMONOBJECT
com/ibm/ws/classloader/CompoundClassLoader@83E31BB8/83E31BC4:
owner "WebContainer : 6" (0x41A48000), entry count 1


The thread that is waiting for the CompoundClassLoader will
indicate that the EngineConfigurationFactoryFinder is being
called when the locking occurs.  Here is an example from a
javacore file:

MTHREADINFO      "WebContainer : 6" (TID:0x403E8300,
s_thread_t:0x413F0374, state:B, native ID:0x00523043) prio=5
ESTACKTRACE          at
va/lang/ClassLoader.loadClass(ClassLoader.java:597(Compiled
Code))
ESTACKTRACE          at
g/apache/commons/discovery/ResourceClass$1.run(ResourceClass.jav
a:119(
mpiled Code))
ESTACKTRACE          at
va/security/AccessController.doPrivileged(AccessController.java:
197(Co
iled Code))
ESTACKTRACE          at
g/apache/commons/discovery/ResourceClass.loadClass(ResourceClass
.java:
5(Compiled Code))
ESTACKTRACE          at
m/ibm/ws/webservices/engine/configuration/EngineConfigurationFac
toryFi
er$1.run(EngineConfigurationFactoryFinder.java:180(Compiled Code

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  IBM WebSphere Application Server V6.1 and   *
*                  V7.0 users of JAX-RPC                       *
****************************************************************
* PROBLEM DESCRIPTION: Lock contention occurs in JAX-RPC       *
*                      EngineConfigurationFactoryFinder,       *
*                      which may degrade performance           *
****************************************************************
* RECOMMENDATION:  Install a fixpack containing this APAR.     *
****************************************************************
If a customer has a large number of threads making
JAX-RPC web service calls, a locking contention may occur.

A javacore file will indicate that the thread is waiting for a
CompoundClassLoader object.  Here is an example from a javacore
file:

2LKMONINUSE      sys_mon_t:0x37FF5680 infl_mon_t: 0x37FF56A8:
3LKMONOBJECT
com/ibm/ws/classloader/CompoundClassLoader@83E31BB8/83E31BC4:
owner "WebContainer : 6" (0x41A48000), entry count 1


The thread that is waiting for the CompoundClassLoader will
indicate that the EngineConfigurationFactoryFinder is being
called when the locking occurs.  Here is an example from a
javacore file:

MTHREADINFO      "WebContainer : 6" (TID:0x403E8300,
s_thread_t:0x413F0374, state:B, native ID:0x00523043) prio=5
ESTACKTRACE          at
va/lang/ClassLoader.loadClass(ClassLoader.java:597(Compiled
Code))
ESTACKTRACE          at
g/apache/commons/discovery/ResourceClass$1.run(ResourceClass.jav
a:119(
mpiled Code))
ESTACKTRACE          at
va/security/AccessController.doPrivileged(AccessController.java:
197(Co
iled Code))
ESTACKTRACE          at
g/apache/commons/discovery/ResourceClass.loadClass(ResourceClass
.java:
5(Compiled Code))
ESTACKTRACE          at
m/ibm/ws/webservices/engine/configuration/EngineConfigurationFac
toryFi
er$1.run(EngineConfigurationFactoryFinder.java:180(Compiled Code

If a substantial number of threads are locked, the performance
of the system is degraded.

Problem conclusion

The EngineConfigurationFactoryFinder does a dynamic load
of classes using the ClassLoader.loadClass method.  This
dynamic load causes synchronous lock contention if the
CompoundClassLoader is one of the class loaders.

The EngineConfigurationFactoryFinder class is changed to detect
the presence of the CompoundClassLoader and use a different
class loading strategy when present.  This change avoids the
locking contention.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.29 and 7.0.0.9.  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
PK97310
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
2009-09-28
Closed date
2009-10-30
Last modified date
2009-10-30

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
R700 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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PK97310: LOCKING CONTENTION ON COMPOUNDCLASSLOADER DUE TO JAX-RPC WEB SERVICE RUNTIME CONFIGURATION

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

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

Document Information

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