Howdy,

>In Unix, java will make
> 512MB swap every time we make a System Runtime call.

I don't think so: can you prove the above?

>Will this
> hurt the Tomcat preformnace? 

Lowering -Xms will only slightly degrade performance during the allocation
phase.  The effects are negligible during that phase and none afterwards.

>I read the article from Sun saying the -Xms and
> -Xmx should be the same.  Is it always true?

No.  Almost nothing in the realm of performance tuning is always true.  Setting
-Xms equal to -Xmx is useful only if you're going to have a constant level
memory usage more or less throughout the life of your JVM.  If you start low
and stay low until peak demand comes in, keeping -Xms low is more beneficial. 
GC and other operations are always faster on a smaller heap.

Of course, nothing is more beneficial then having stress tests to run against
different combinations of settings.  That way you can see the actual effect on
your system intead of relying on me or someone else's article.

Yoav Shapira



=====
Yoav Shapira
[EMAIL PROTECTED]

__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to