Architecting Systems with Elixir

[cjbottaro]

Ohh buddy, you’re gunna stir the hornet’s nest with this one!

What’s wrong with Umbrella Apps?

I like Umbrella projects and pretty much always use them for personal Elixir stuff, especially Nerves things. But I don’t think this is a popular choice. I’ve never really understood why they are disliked. The two arguments I’ve read against them don’t check out for me: you can’t control the order of config loading (yes you can) and they are for deploying things separately (no they’re not). Admittedly I have never worked on a huge Umbrella project; The massive monoliths I’ve worked on have all…

My day job has a similar setup as you. We started with an umbrella app, but then just merged everything into a monolithic Elixir app with multiple top level namespaces… and I think it’s MUCH more simple.

We also use Kubernetes… but it’s more about individually scalable deployments, not code separation. We have dozens of Kubernetes deployments, most of them hooked up to HPA, but they all use a shared “Elixir app” build image.

Also, the concept of “RPC” in a dynamically typed language is interesting to me… We have “RPC” which is really just API calls over BSON+NATS (as opposed to JSON+HTTP). But is that really RPC? Isn’t RPC all about static type analysis, i.e. making remote calls look like local calls, including static type checking?