Load Testing a Rails Application - What tool is most used??? (performance testing / benchmarking)

Hi all,

I’m keen to develop a way to load test my rails application, as a way to check if there are any bottlenecks (bugs, bad design) and that it will scale ok.

Q1:
What’s the most used load testing tool by Rails developers? I know there are several web application load test tools out there, but are there any (open source/cheap) that are particularly suited to Rails for any reason?

Q2: Ideally the tool would pull server O/S stats to present along with HTTP response stats (e.g. server CPU, memory etc). I’m currently stuck developing on Windows but host on Dreamhost (unix). Which tool would be recommended to access/present such detail as well?

Tks
Greg