how many mongrel servers to setup

Is there a formula, data points etc that I can use to decide how many mongrel servers is the optimal/max for a mongrel cluster setup on a box?

i.e what should I look for in terms of processing, load etc.

Thanks.

From what I’ve heard, 50MB per mongrel is a conservative estimate, sometimes they will take up a lot more. There have been plenty of threads already on this, something a little searching should be able to turn up.

You could take a look at Phusion Passenger at http://www.modrails.com/index.html

nextpulse wrote:

Is there a possibility of setting up a test server and then testing out a few different methods of hosting your application? Mongrel, Thin, and Passenger all deserve considering (IMHO), but you need to test them in order to find the best setup for your application and group.

I think you just need some quick back of the envelope calculations: if an individual mongrel can serve 50 requests/s and your site needs to be able to deal with 80 requests a second then you need 2 mongrels (of course it's never quite as simple, obviously some usage patterns or tasks on your app will be slower than others, you just need some sort of representative sample of what 1 mongrel can handle compared to what the whole site can handle).

Fred