PQ69279: SLOW PERFORMANCE IN CODE WHEN USING MANY SYSTEM.OUT.PRINTLN() ENTRIES

Fixes are available
WebSphere Application Server Version 3.5 Fix Pack 7 (3.5.7)
System Management Component Cumulative Fix for 4.0.2/4.0.3/4.0.4 /4.0.5

APAR

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 numberPQ69279
Reported component nameWAS STANDARD NT
Reported component ID5648C8301
Reported release350
StatusCLOSED PER
PENoPE
HIPERNoHIPER
Submitted date2002-12-18
Closed date2003-01-13
Last modified date2003-05-05

APAR is sysrouted FROM one or more of the following:

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

PQ72332PQ73846

Modules/Macros

Fix information
Fixed component nameWAS STANDARD NT
Fixed component ID5648C8301
APAR is sysrouted TO one or more of the following:PQ72332PQ73846Modules/Macros

Applicable component levels
R350 PSYUP











Document Information

Product categories: Software, Application Servers, Distributed Application & Web Servers, WebSphere Application Server, General
Software version: 350
Reference #: PQ69279
IBM Group: Software Group
Modified date: 2003-05-05