Thanks Barney & Wil. Our application performs under extreme load 24/7. Interacts with a database that is highly volatile (lots of inserts), with tables/views containing millions of rows. Currently, the instances are set to the default of 25 (2 of the stacks are set to 28 per instance). I don't know how/when these values were determined, but we're looking at it now, and want to understand how changing these _could_ affect performance, either negatively or positively.
Cheers, Kris > Exactly what Barney said. It's app and hardware specific. On our > servers we run one CF8 instance per server and we're set to handle up > to 100 simultaneous requests. Once in a while we hit that limit. > >> That's a starting point, and needs to be tuned for your specific >> application, so it's kind of irrelevant how good of an estimate it is. >> I'd say each instance gets (4 * CPUs / instances) to start with, and >> then do your tuning from there. And make sure if your instances are >> sharing hardware resources that you're loading all the instances that >> share the hardware when you test or you'll skew your results. >> That last app I tuned like this we settled on 20 concurrent requests. >> We ran one instance per physical machine, and each machine had a >> single CPU. About 6 month later we updated the application, retuned, >> and optimized to 8 concurrent requests. Then we started doing secure >> media delivery and jacked it way up to 50 concurrent requests. So >> it's REALLY application specific. >>> I've read in various places that the recommended starting point for >>> determining the Max Simultaneous Requests (MSR) value is 3-4 per CPU. >>> But I'm not seeing how this works in a vertical cluster. Say I have a >>> box with 4 CPUs, and 4 instances on that box. How would that suss- >>> out? >>> >>> Do you set each instance to use only it's share of the MSR, or a >>> full MSR? >>> >>> What about a box where the CPUs don't evenly match the number of >>> instances? 4 CPUs, 3 instances, as an example. Does this m ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Adobe® ColdFusion® 8 software 8 is the most important and dramatic release to date Get the Free Trial http://ad.doubleclick.net/clk;207172674;29440083;f Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:320140 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4
