I’ve seen lots of teams trying to increase the availability of GitHub runners for their organization by implementing GitHub Actions Runner Controller (ARC). In some cases, they hope to try to exceed GitHub’s 99.9% SLA. Unfortunately, the math works against them. In this post, I’ll explain why.

One challenge with the GitHub’s Actions Runner Controller (ARC) is that it does not officially support Windows containers for the runners. With a little bit of work, though, it’s possible to make this configuration work on a hybrid Linux/Windows cluster.