In previous post, I explained how I wrote a rate limiter for dnsdist using fixed window algorithm and redis. In this post, I will show how I write a rate limiter without Redis, this method give me a higher performance.

dnsdist is a highly DNS-, DoS- and abuse-aware loadbalancer. Its goal in life is to route traffic to the best server, delivering top performance to legitimate users while shunting or blocking abusive traffic. dnsdist has supported a basic rate-limiting but it wasn’t fit to my case, and I wrote a custom Lua code to implement own rate-limiting function.