[belter]

BEAM performance model trades throughput for isolation, which hurts CPU-bound tasks, and ironically, whenever you need speed, you end up using NIFs that break BEAM safety guarantees, and reintroduce the exact fragility Elixir was supposed to avoid.

In 2025, Elixir is a beautiful system for a niche that infrastructure has already abstracted away.

[jimbokun]

> In 2025, Elixir is a beautiful system for a niche that infrastructure has already abstracted away.

Do you mean Kubernetes?

My mental model of Erlang and Elixir is programming languages where the qualities of k8s are pushed into the language itself. On the one hand this restricts you to those two languages (or other ports to BEAM), on the other hand it allows you to get the kinds of fall over, scaling, and robustness of k8s at a much more responsive and granular level.

[creata]

> whenever you need speed, you end up using NIFs that break BEAM safety guarantees, and reintroduce the exact fragility Elixir was supposed to avoid.

That's like complaining that unsafe{} breaks Rust's safety guarantees. It's true in some sense, but the breakage is in a smaller and more easily tested place.

[jlouis]

It's not isolation which hampers throughput. That's a red herring. In fact, isolation increases throughput, because it reduces synchronization. A group of isolated tasks are embarrassingly parallel by definition.

The throughput loss stems from a design which require excessive communication. But such a design will always be slow, no matter your execution model. Modern CPUs simply don't cope well if cores need to send data between them. Neither does a GPU.

[creata]

But the isolation is what necessitates (or at least encourages) a design that requires more communication, isn't it?

[jlouis]

Not a priori.

The grand design of BEAM is that you are copying data rather than passing it by reference. A copy operation severs a data dependency by design. Once the copy is handed somewhere, that part can operate in isolation. And modern computers are far better at copying data around than what people think. The exception are big-blocks-of-data(tm), but binaries are read-only in BEAM and thus not copied.

Sure, if you set up a problem which requires a ton of communication, then this model suffers. But so does your GPU if you do the same thing.

As Joe Armstrong said: our webserver is a thousand small webservers, each serving one request.

Virtually none of them have to communicate with each other.