tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Caldarale, Charles R" <Chuck.Caldar...@unisys.com>
Subject RE: tomcat CPU utilization pegged...total CPU only 50%
Date Tue, 08 Feb 2005 06:03:56 GMT
> From: Kevin Williams [mailto:KWilliams@centerlogic.com]
> Subject: RE: tomcat CPU utilization pegged...total CPU only 50%
> 
> The two Xeon CPU's are hyperthreaded to represent 4 CPU's 
> on the machine.  I'm not sure exactly how tomcat/java 
> interact with this, but it was not favorable.

Other than for determining the number of threads to use for parallel GC, the JVM does not
care how many CPUs there are.  I don't know what Windows returns for the number of CPUs installed
when hyperthreading is enabled, but you can determine that with the Runtime.availableProcessors()
method.

You really should be measuring performance by some measurement of actual workload completed,
not CPU utilization.  Turning off hyperthreading may actually reduce your overall throughput.
 (Then again, it might make it better - very application dependent.)

 - Chuck


THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus
for use only by the intended recipient. If you received this in error, please contact the
sender and delete the e-mail and its attachments from all computers.

---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org


Mime
View raw message