We ran an 8 month test on one of our applications (heavy use - high mem load) and found this type of GC to be bad, very bad - there were on twin 3ghz Xeon machines. Basically the app would run great for a while but when it did its GC - which essentially a global GC it would pause the app stopping connections to JRun - obviously tweaking the JVM is Application specific *there is no optimum setup or everyone*.
-----Original Message----- From: Andy Allan [mailto:[EMAIL PROTECTED] Sent: 15 April 2005 09:38 To: CF-Talk Subject: Re: sorry, back to JVM/GC for a moment Mmmm, I need to read to emails more closely... :) This collector CAN be used on multiple CPU machines and just to quote the Sun JVM docs (as I can't be botherd rehashing it myself) "Use the concurrent low pause collector if your application would benefit from shorter garbage collector pauses and can afford to share processor resources with the garbage collector when the application is running. Typically applications which have a relatively large set of long-lived data (a large tenured generation), and run on machines with two or more processors tend to benefit from the use of this collector. However, this collector should be considered for any application with a low pause time requirement. Optimal results have been observed for interactive applications with tenured generations of a modest size on a single processor." Andy On 4/15/05, Andy Allan <[EMAIL PROTECTED]> wrote: > -XX:+UseConcMarkSweep can be used successfully on single CPU machines. > > This collector cleans up the tenured generation in parallel with the > execution of the application but it doesn't actually require multiple > CPUs (although it will of course benefit from 2+ CPUs) > > Andy > > On 4/15/05, Robertson-Ravo, Neil (RX) > <[EMAIL PROTECTED]> wrote: > > This -XX:+UseConcMarkSweepGC should not be used on a dual processor box. You > > can remove it altogether to get better 0performance. > > > > > > -----Original Message----- > > From: Dov Katz [mailto:[EMAIL PROTECTED] > > Sent: 15 April 2005 02:53 > > To: CF-Talk > > Subject: sorry, back to JVM/GC for a moment > > > > Final sanity check. Please advise if I should change anything. (w2k server > > 2 1ghz proc with 1gb ram - sharing sql on same box) > > > > I have the following JVM setting, after I modified it last week. Things seem > > good, but what else should I be looking to optimize things? What might be > > wrong/inefficient here? Thanks > > -dov > > > > -server -DJINTEGRA_NATIVE_MODE -DJINTEGRA_PREFETCH_ENUMS -Xms256m -Xmx512m > > -Dsun.io.useCanonCaches=false > > -Xbootclasspath/a:"{application.home}/../lib/webchartsJava2D.jar" > > -XX:MaxPermSize=128m -XX:PermSize=64m -XX:NewSize=64m > > -XX:+UseConcMarkSweepGC > > -Djavax.xml.parsers.SAXParserFactory=com.macromedia.crimson.jaxp.SAXParserFa > > ctoryImpl > > -Djavax.xml.parsers.DocumentBuilderFactory=com.macromedia.crimson.jaxp.Docum > > entBuilderFactoryImpl > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Discover CFTicket - The leading ColdFusion Help Desk and Trouble Ticket application http://www.houseoffusion.com/banners/view.cfm?bannerid=48 Message: http://www.houseoffusion.com/lists.cfm/link=i:4:203006 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
