Go memory ballast: How I learnt to stop worrying and love the heap

Go memory ballast: How I learned to stop worrying and love the heap

I’m a big fan of small code changes that can have large impact. This may seem like an obvious thing to state, but let me explain:

  1. These type of changes often involve diving into and understanding things one is not familiar with.
  2. Even with the most well factored code, there is a maintenance cost to each optimization you add, and it’s usually (although not always) pretty linear with the amount of lines of code you end up adding/changing.

We recently rolled out a small change that reduced the CPU utilization of our API frontend servers at Twitch by ~30% and reduced overall 99th percentile API latency during peak load by ~45%.

This blog post is about the change, the process of finding it and explaining how it works.