tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From André Warnier ...@ice-sa.com>
Subject Re: Tomcat 100% CPU usage after moving from Java 5 to 6
Date Tue, 26 Jan 2010 09:24:00 GMT
Jesse Klaasse wrote:
> I have now fixed the infinite loop, and again did the update from Java 5 to
> Java 6. This time all seems to be working like a charm!
> 
> Along with fixing the infinite loop, I have dug a little deeper into the JVM
> arguments. I found the following article particularly useful:
> http://confluence.atlassian.com/display/DOC/Garbage+Collector+Performance+Issues
> 
> Using that article plus common sense, my arguments are now:
> -Djavax.sql.DataSource.Factory=org.apache.commons.dbcp.BasicDataSourceFactory
> -Dcom.sun.management.jmxremote -XX:MaxPermSize=512m
> -Xloggc:D:\logs\gc\tomcat-gc.log -X:+PrintGCDetails -XX:+UseConcMarkSweepGC
> -XX:+UseTLAB -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled
> -XX:+DisableExplicitGC -XX:NewSize=4096m -Xms10240m -Xmx10240m
> 
> The NewSize parameter was new to me, and it's explanation on the
> aforementioned link made much sense.
> A few things I'm still not completely sure about:
> - I don't want any serial garbage collection to occur. I'm not sure whether
> my arguments take care of this now..
> - Do I still need the -XX:+UseTLAB argument?
> - Do I still need the -XX:+CMSClassUnloadingEnabled flag?
> - Do I still need the -XX:+CMSPermGenSweepingEnabled flag?
> 
> So, still some research to be done. 
> 
> In the meantime I am very pleased with the results. Tomcat's CPU usage seems
> significantly lower than before (it's average seems about 10% now - which
> was 30-40% before) - scary! 

Jesse,
thanks for the feedback.
1) for the people here trying to help, it just "feels nice" to know that 
they have actually done so.
2) the searchable archives of this list are a real resource in case of 
problems (at least for the people who bother to search them before 
asking questions).  Having the solution to the problem contained in the 
archive is certainly a plus.


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


Mime
View raw message