PQ72332: SLOW PERFORMANCE IN CODE WHEN USING MANY SYSTEM.OUT.PRINTLN() ENTRIES | |||||||||||||||||||||||||||||||||||||||||||||
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![]() 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 is sysrouted FROM one or more of the following: PQ69279 APAR is sysrouted TO one or more of the following: Modules/Macros Publications Referenced
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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
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