Learn to Fly.io with AnyCable

Video 📼

In this episode, we explore Fly.io capabilities in deploying Rails real-time applications:

• Deploying a pure Rails Action Cable application to Fly.

• Load-testing Flying Action Cable with k6 and xk6-cable.

• Deploying RPC-less version of AnyCable and load-testing it.

• Adding RPC server to the equation with just a couple of configuration changes.

• Exporting AnyCable metrics to fly-metrics.io.

Benchmark results

• Action Cable server (single-worker Puma) crashed due to out-of-memory at about 700 concurrent connections.

• AnyCable (RPC-less) passed 2700 concurrent connections and consumed only a half of the available RAM (~120MB).

Links:

• Official Fly deployment guide for AnyCable

• Fly.io Rails guides

• Real-time stress: AnyCable, k6, WebSockets, and Yabeda

Errata:

• Getting an app's Ruby version from the Gemfile has been fixed in the recent flyctl versions (see issue)

• Redis connections termination is intentional and has nothing with load-testing. See the Fly docs