PQ78294: HIGH CPU EXPERIENCED USING WORK AREA SERVICES

APAR status
Closed as program error.

Error description
Customers may notice high CPU when using work area services.
JVM thread dump shows threads in object serialization.
work area services is an enterprise offering which
allows the user to trace transactions internally.
websphere enterprise work area services high CPU
Local fix Problem summary
****************************************************************
* USERS AFFECTED: Applications that use the WorkArea service   *
*                 on WebSphere PME 5.0 or 5.0.1 are affected.  *
****************************************************************
* PROBLEM DESCRIPTION: Every set operation into the work       *
*                      area service automatically results in   *
*                      the serialization of the new            *
*                      attribute. Every get operation from     *
*                      the work area service automatically     *
*                      results in the deserialization of the   *
*                      new attribute. Excessive                *
*                      serialization can result in             *
*                      observable performance degradation      *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
I. To enable caching of work area attributes on the server:
1) Log onto the WebSphere Administrative Console.
2) Expand Servers -> Application Servers
3) Select a server on which to enable work area caching
4) Under Additional Properties, select Work Area Service
5) Under Additional Properties, select Custom Properties
6) If a property named lazySerialization already exists and is
set to "false", remove the property. If the lazySerialization
property is already set to "true", then work area caching is
already enabled for this server and no further action needs to
be taken.
7) Select the New button to create a new property.
8) Set the property's name to: lazySerialization
9) Set the property's value to: true
10) Click OK to apply the changes.
11) Click the Save link under Messages and click the Save
button to persist the new property.
12) Log out from the Administrative Console.
13) Restart the server.

II. To disable caching of work area attributes on the server:
1) Log onto the WebSphere Administrative Console.
2) Expand Servers -> Application Servers
3) Select a server on which to enable work area caching
4) Under Additional Properties, select Work Area Service
5) Under Additional Properties, select Custom Properties
6) If there is no property named lazySerialization, or if the
property exists but is not set to "true", then work area
caching is already disabled on this server and no further
action needs to be taken.
7) Select the check box beside the lazySerialization property.
8) Click the Delete button to remove the property.
9) Click OK to apply the changes.
10) Click the Save link under Messages and click the Save
button to persist the new property.
11) Log out from the Administrative Console.
12) Restart the server.

III. To enable caching of work area attributes on a client:
Specify the jvm system property
com.ibm.websphere.workarea.lazySerialization=true when
launching the J2EE Application Client Tool. Example:
  launchClient userApp.ear
-CCDcom.ibm.websphere.workarea.lazySerialization=true arg1 arg2


  When lazy serialization is enabled in a client or server
process, attributes set into the work area service will not be
automatically serialized during the set operation. If the
attribute is mutable, then changes to the object will be
reflected in the work area's reference to that attribute. When
the thread with which the attribute is associated makes a
remote IIOP invocation, the attribute will be serialized, and
the serialized form of the attribute will be cached. So long
as the attribute is not reset into the work area, notify the
work area service that the attribute has been modified,
changes to the original attribute will continue to be
reflected within the attribute contained within the work area
because the work area holds only a cached reference to the
original object. However, so long as the work area service has
not been told that the attribute has changed by resetting the
attribute into the work area, then subsequent remote requests
will continue to use the cached serialized verion of the
attribute and direct changes to the mutable attribute will not
be propagated.
  The work area service will release cached references and
cached serialized verions of attributes when the attribute is
reset or removed, or when the work area is explicitely
completed by the application, or when the server component
ends execution of the request during which the work area was
begun, or when the client process which began the work area
terminates.

PQ75942 must be installed before PQ78294 is installed.
Problem conclusion
With the fix to this apar, the WorkArea Service will minimize
the serialization and deserialization of a users context.
This should help to improve performance in those applications
that make use of the WorkArea Service.
Temporary fix Comments
APAR information
APAR number PQ78294
Reported component name WAS ENTERPRISE
Reported component ID 5630A3700
Reported release 00A
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2003-09-09
Closed date 2003-10-24
Last modified date 2003-10-24

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
acwa          

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00S PSY    UP
R00W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Enterprise Edition (EE)
Operating system(s):
Software version: 00A
Software edition:
Reference #: PQ78294
IBM Group: Software Group
Modified date: Oct 24, 2003