koto VS Rouille, Rust web server middleware

Putting the finishing touches on a procedural macro to bind Rust code to koto we want to use in synth. Also a blog post about it is on the way.

I'm currently trying to improve the vtable dispatch in koto (because I want to use it in synth).

I've been working on Koto which is intended for this kind of use case. I've been thinking about extending Rust applications with scripting, and I have games in mind but more generally I'm interested in rapid iteration in creative applications. It's still very early so I haven't shared it more widely but I'd be curious to hear what you think.

https://github.com/koto-lang/koto

Your CRUD web application server almost certainly doesn't need async Rust. Using a blocking HTTP server is not "might be a good idea", it simply is a good idea.

I recommend Rouille for this: https://github.com/tomaka/rouille. In case you are worried about performance, check the benchmark. Blocking Rouille is faster than builtin async server in Node.js.

As you say, the majority of the web ecosystem in Rust has moved to async - but if you’re happy to stray a bit from the beaten path then rouille might do the trick.

In strongly typed languages like Rust, composing smaller libraries is usually quite painless, so you don't need a large framework.

Personally for backend Rust I use rouille[0] for the server (it's very simple and async-free), askama[1] for compile-time HTML templates and (if a SPA is unavoidable, as that is of course always to be avoided if at all possible) yew[2] for client-side WASM.

Now this stack is what I like personally, but there are many options that you can combine, some more full-featured than others. Check out https://www.arewewebyet.org/ for a partial overview.

[0]: https://github.com/tomaka/rouille

[1]: https://github.com/djc/askama

[2]: https://yew.rs/

rouille

I'd like to put in a word for a simple, sync framework such as rouille. The compile times are much, much better, the number of dependencies is much smaller, the stuff it's built on (the standard library) is extensively tested and extremely reliable. Kernel context switches are slower than userspace thread scheduling, but not much slower, and as long as your services aren't just shoving bytes from one place to another (i.e. actually doing some computation) the time taken for a context switch vanishes into noise. A lot of benchmarks test how quickly a web service can move bytes, which (if your business logic is non-trivial) actually isn't the most critical factor.

I don't have any Rust-relevant experience here, but if I wanted to build a web server in Rust and was okay with "reasonable" performance, I'd probably give rouille a try first.

Rouille is fairly solid in my experience. Save the pain of async and spend it building software that works. Honestly with Rust's lack of GC you get predictable response times already.

How would you differentiate it from let's say Rouille ?