embly VS workers-rs

Hey, I tried to build something like this too: https://github.com/embly/embly

My takeaway after building that is that the build tooling is the major pain point. If you're trying to onboard someone onto this platform from their favorite language the hard part is getting from code to the .wasm file. wasm-bindgen (as an example) has put so much effort into build tooling, I wonder if that's a necessary path for success here.

It's also great that WASI exists now, if I had to do embly again I'd just use wasi and then implement all of my "platform" features as filesystem features, not syscalls. If your API interface is the filesystem then you could provide interoperability between environments. Let's say you want to include a key-value store in the wasi runtime, you just make the keys files and the values file contents. Then you could so something like ship a FUSE filesystem to interact with the filesystem in the same way from a traditional VM or on a personal computer. I got really bogged down in custom syscalls and this path seems potentially more elegant.

Have you also thought about live process migration? I got really excited about this from a technical standpoint. Since you completely control the runtime you could set up a clustered wasm solution that moves long running processes from VM to VM by sending their live memory state to another machine. Not sure if that's actually useful, but cool that it's not bogged down by the usual complexities of doing the same in a full OS environment.

Anyway, so glad to see that someone is taking this idea on. Please make a cloud platform and let me pay for it. Also happy to chat more if any of this is useful, I've joined your discord as "max".

- The speed of the Python interpreter running in WebAssembly

Today, Python cold starts are slower than cold starts for a JavaScript Worker of equivalent size. A basic "Hello World" Worker written in JavaScript has a near zero cold start time, while a Python Worker has a cold start under 1 second.

That's because we still need to load Pyodide into your Worker on-demand when a request comes in. The blog post describes what we're working on to reduce this — making Pyodide already available upfront.

Once a Python Worker has gone through a cold start though, the differences are more on the margins — maybe a handful milliseconds, depending on what happens during the request.

- There is a slight cost (think — microseconds not milliseconds) to crossing the "bridge" between JavaScript and WebAssembly — for example, by performing I/O or async operations. This difference tends to be minimal — generally something measured in microseconds not milliseconds. People with performance sensitive Workers already write them in Rust https://github.com/cloudflare/workers-rs, which also relies on bridging between JavaScript and WebAssembly.

- The Python interpreter that Pyodide provides, that runs in WebAssembly, isn't as fast as the years and years of optimization that have gone into making JavaScript fast in V8. But it's still relatively early days for Pyodide, compared to the JS engine in V8 — there are parts of its code where we think there are big perf gains to be had. We're looking forward to upstreaming performance improvements, and there are WebAssembly proposals that help here too.

Not yet, but we're working on that https://github.com/cloudflare/workers-rs/pull/324

I'm also in the Workers org but I have had a bit of interaction with Rust. There's some Rust in the Workers runtime using lol-html for HTMLRewriter as well as some tooling and there's the full blown workers-rs framework that I work on, but that's about it for the Rust I work on regularly.

I'm an engineer at Cloudflare working on Workers (and a maintainer of workers-rs) and I'd love to help whoever ends up maintaining this get that PR rewriting it in Rust across the line.

GitHub - cloudflare/workers-rs: Write Cloudflare Workers in 100% Rust via WebAssembly

I never said it was, but thankfully nowadays there are plenty of other tools that are fast enough to keep the dev cycle quick. Personally esbuild is my go-to when I need a bundler but I've grown really fond of SWC native api, we used to use it at work for our wasm build tool for our workers-rs framework.

There's actually a rust framework for Workers https://github.com/cloudflare/workers-rs

I'm a maintainer of the of the Cloudflare workers-rs project to allow you to write serverless functions in Rust running as WASM in our V8-based runtime. There's certainly some rough spots (doesn't have complete parity with our default JS runtime apis), but if you're concerned with cold start times and you don't need a full containerized environment I think it's a solid choice.

Most likely, it should, we just haven't had the time to fully implement it or add a library to wrap the FFI. Please let us know you need a feature by opening an issue.

I may be biased, as the original project author, but I’d recommend using Cloudflare Workers https://github.com/cloudflare/workers-rs - totally free their with very generous limits.