PQ72332: SLOW PERFORMANCE IN CODE WHEN USING MANY SYSTEM.OUT.PRINTLN() ENTRIES

 Fixes are available

5.0.1: WebSphere Application Server Version 5.0 Fix Pack 1 (Version 5.0.1)
5.0.1: WebSphere Application Server Enterprise Edition Version 5.0 Fix Pack 1



APAR status
Closed as program error.

Error description
Customer has noted that upon upgrading from WAS 2.0.3.X to WAS
3.5.X a severe degradation of performance, apparently related
to numerous System.out.println() entries. When those entries are
removed, the application runs as quickly as previously noted.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server users of 3.5.6  *
*                 but may occur on previous 3.5 versions       *
****************************************************************
* PROBLEM DESCRIPTION: System.out.println - buffering and      *
*                      performance problem                     *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
In certain configurations, the system is not doing write
operation caching, which causes a massive amount of IO disk
calls.  This would lead to the performance degradation noted
by the customer.
Problem conclusion
The default behavior has been changed to not set the flag
FILE_FLAG_WRITE_THROUGH which turns off intermediate cache
and goes directly to disk. The system can still cache write
operations, but cannot lazily flush them.  The flag can be
enabled by setting IMMEDIATE_LOGWRITE=TRUE in an environment
variable before invoking the server.  In general, not setting
the flag should yield better performance.
Temporary fix Comments
APAR information
APAR number PQ72332
Reported component name WAS BASE 5.0
Reported component ID 5630A3600
Reported release 00W
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2003-03-21
Closed date 2003-03-21
Last modified date 2003-03-21

APAR is sysrouted FROM one or more of the following:
PQ69279

APAR is sysrouted TO one or more of the following:

Modules/Macros

Publications Referenced

Fix information
Fixed component name WAS BASE 5.0
Fixed component ID 5630A3600

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


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 00W
Software edition:
Reference #: PQ72332
IBM Group: Software Group
Modified date: Mar 21, 2003