APAR status
Closed as new function.
Error description
The WAS user-space class loaders (application, shared library, and extension class loaders) do not currently support the optional Java parallel class loading architecture, which allows classes of different names to be loaded simultaneously by a single class loader. Currently, the loadClass() method itself is synchronized in these loaders, so a class loader is locked by all class loads performed using it.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM WebSphere Application * * Server * **************************************************************** * PROBLEM DESCRIPTION: WAS class loaders do not support * * parallel * * class loading * **************************************************************** * RECOMMENDATION: * **************************************************************** Java 7 modified the ClassLoader.loadClass() API to include optional support for parallel class loading, removing the synchronization from the loadClass() method and instead locking on a combination of the class loader and the class being loaded, allowing multiple threads to simultaneously use the same class loader. WAS' application and server level loaders did not implement this optional behavior, which could lead to increased contention and performance issues in environments where multiple threads were attempting to load classes using the same class loader.
Problem conclusion
Server class loaders have been updated to support Java parallel class loading. The fix for this APAR is targeted for inclusion in fix pack 9.0.5.6. For more information, see 'Recommended Updates for WebSphere Application Server': https://www.ibm.com/support/pages/node/715553
Temporary fix
Comments
APAR Information
APAR number
PH26130
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
900
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-06-08
Closed date
2020-11-24
Last modified date
2020-11-24
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
WEBSPHERE APP S
Fixed component ID
5724J0800
Applicable component levels
R900 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":"9.0","Line of Business":{"code":"LOB45","label":"Automation"}}]
Document Information
Modified date:
01 November 2021