Design of a Rate Limiter

High-level design

A rate limiter can be deployed as a separate service that will interact with a web server, as shown in the figure below. When a request is received, the rate limiter suggests whether the request should be forwarded to the server or not. The rate limiter consists of rules that should be followed by each incoming request. These rules define the throttling limit for each operation. Let’s go through a rate limiter rule from Lyft, which has open-sourced its rate limiting component.