Best practice for rate limiting users of a REST API?

Question

I am putting together a REST API and as I\'m unsure how it will scale or what the demand for it will be, I\'d like to be able to rate limit uses of it as well as to be able

Answer 1

Good answers already - if you don't want to implement the limiter yourself, there are also solutions like 3scale (http://www.3scale.net) which does rate limiting, analytics etc. for APIs. It works using a plugin (see here for the ruby api plugin) which hooks into the 3scale architecture. You can also use it via varnish and have varnish act as a rate limiting proxy.