If you run top, and make a servlet to call a System Runtime. Then, use Jmeter to hammer it. You will see the swap disk is create the same size as the -Xms for each thread. I have done the test with different sizes of heap. It is solid true.
Billy Ng ----- Original Message ----- From: "Yoav Shapira" <[EMAIL PROTECTED]> To: "Tomcat Users List" <[EMAIL PROTECTED]>; "Billy Ng" <[EMAIL PROTECTED]> Sent: Tuesday, June 17, 2003 4:40 AM Subject: Re: heap size config > 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] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
