workers-rs VS wasmtime

- 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.

Just a documentation change, fortunately:

https://github.com/bytecodealliance/wasmtime/commits?author=...

They've submitted little documentation tweaks to other projects, too, for example:

https://learn.microsoft.com/en-us/cpp/overview/whats-new-cpp...

I don't know whether this is a formerly-legitimate open source contributor who went rogue, or a deep-cover persona spreading innocuous-looking documentation changes around to other projects as a smokescreen.

WebAssembly is extremely portable. WebAssembly runs on: all major web browsers, V8 runtimes like Node.js, and independent Wasm runtimes like Wasmtime, Lucet, and Wasmer.

cpu: 4 disk: 60 memory: 12 arch: host hostname: colima autoActivate: true forwardAgent: false # I only tested this with 'docker', not 'containerd': runtime: docker kubernetes: enabled: false version: v1.24.3+k3s1 k3sArgs: [] network: address: true dns: [] dnsHosts: host.docker.internal: host.lima.internal # Added: # - containerd-snapshotter: true (meaning containerd will be used for pulling images) docker: features: buildkit: true containerd-snapshotter: true vmType: vz rosetta: true mountType: virtiofs mountInotify: false cpuType: host # This provisioning script installs build dependencies, WasmEdge and builds the WASM runtime shims for containerd. # NOTE: this takes a LOOONG time! provision: - mode: system script: | [ -f /etc/docker/daemon.json ] && echo "Already provisioned!" && exit 0 echo "Installing system updates:" apt-get update -y apt-get upgrade -y echo "Installing WasmEdge and runwasi build dependencies:" # NOTE: packages curl, git and python3 already installed: apt-get install -y make gcc build-essential pkgconf libtool libsystemd-dev libprotobuf-c-dev libcap-dev libseccomp-dev libyajl-dev libgcrypt20-dev go-md2man autoconf automake criu pkg-config libdbus-glib-1-dev libelf-dev libclang-dev libzstd-dev protobuf-compiler apt-get clean -y - mode: user script: | [ -f /etc/docker/daemon.json ] && echo "Already provisioned!" && exit 0 # # Setting vars for this script: # # Which WASM runtimes to install (wasmedge, wasmtime and wasmer are supported): WASM_RUNTIMES="wasmedge wasmtime wasmer" # # Location of the containerd config file: CONTAINERD_CONFIG="/etc/containerd/config.toml" # # Target location for the WASM runtimes and containerd shims ($TARGET/bin and $TARGET/lib): TARGET="/usr/local" # # Install rustup: # echo "Installing rustup for building runwasi:" curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --default-toolchain none -y source "$HOME/.cargo/env" # # Install selected WASM runtimes and containerd shims: # [[ -z "${WASM_RUNTIMES// /}" ]] && echo "No WASM runtimes selected - exiting!" && exit 0 git clone https://github.com/containerd/runwasi echo "Installing WASM runtimes and building containerd shims: ${WASM_RUNTIMES}:" sudo mkdir -p /etc/containerd/ containerd config default | sudo tee $CONTAINERD_CONFIG >/dev/null for runtimeName in $WASM_RUNTIMES; do case $runtimeName in wasmedge) echo "Installing WasmEdge:" curl -sSfL https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | sudo bash -s -- -p $TARGET echo echo "`wasmedge -v` installed!" ;; wasmtime) echo "Installing wasmtime:" curl -sSfL https://wasmtime.dev/install.sh | bash sudo cp .wasmtime/bin/* ${TARGET}/bin/ rm -rf .wasmtime echo "`wasmtime -V` installed!" ;; wasmer) echo "Installing wasmer:" curl -sSfL https://get.wasmer.io | sh sudo cp .wasmer/bin/* ${TARGET}/bin/ sudo cp .wasmer/lib/* ${TARGET}/lib/ rm -rf .wasmer echo "`wasmer -V` installed!" ;; *) echo "ERROR: WASM runtime $runtimeName is not supported!" exit 1 ;; esac cd runwasi echo "Building containerd-shim-${runtimeName}:" cargo build -p containerd-shim-${runtimeName} --release echo "Installing containerd-shim-${runtimeName}-v1:" sudo install ./target/release/containerd-shim-${runtimeName}-v1 ${TARGET}/bin sudo ln -sf ${TARGET}/bin/containerd-shim-${runtimeName}-v1 ${TARGET}/bin/containerd-shim-${runtimeName}d-v1 sudo ln -sf ${TARGET}/bin/containerd-shim-${runtimeName}-v1 ${TARGET}/bin/containerd-${runtimeName}d echo "containerd-shim-${runtimeName} installed." cd .. echo "[plugins.\"io.containerd.grpc.v1.cri\".containerd.runtimes.${runtimeName}]" | sudo tee -a $CONTAINERD_CONFIG >/dev/null echo " runtime_type = \"io.containerd.${runtimeName}.v1\"" | sudo tee -a $CONTAINERD_CONFIG >/dev/null done echo "containerd WASM runtimes and shims installed." # # Restart the systemctl services to pick up the installed shims. # NOTE: We need to 'stop' docker because at this point the actual daemon.json config is not yet provisioned: # echo "Restarting/reloading docker/containerd services:" sudo systemctl daemon-reload sudo systemctl restart containerd sudo systemctl stop docker sshConfig: true mounts: [] env: {}

When you say wasm container, you mean something like wasmtime that provides a non-browser wasm runtime?

https://github.com/bytecodealliance/wasmtime

We can't run this directly from the command line unless we install some runtime like wasmtime:

The roadmap I linked above. The WASI folks have done a poor job at communicating, no doubt, but I'm surprised someone like yourself literally building a competitor spec isn't following what they are doing closely.

Just for you I did some googling: see here[0] for the current status of WASI threads overall, or here[1] and here[2] for what they are up to with WASI in general. In this PR[3] you can see they enabled threads (atomic instructions and shared memory, not thread creation) by default in wasmtime. And in this[4] repository you can see they are actively developing the thread creation API and have it as their #1 priority.

If folks want to use WASIX as a quick and dirty hack to compile existing programs, then by all means, have at it! I can see that being a technical win. Just know that your WASIX program isn't going to run natively in wasmtime (arguably the best WASM runtime today), nor will it run in browsers, because they're not going to expose WASIX - they're going to go with the standards instead. so far you're the only person I've met that thinks exposing POSIX fork() to WASM is a good idea, seemingly because it just lets you build existing apps 'without modification'.

Comical you accuse me of being polarizing, while pushing for your world with two competing WASI standards, two competing thread creation APIs, and a split WASM ecosystem overall.

[0] https://github.com/bytecodealliance/jco/issues/247#issuecomm...

[1] https://bytecodealliance.org/articles/wasmtime-and-cranelift...

[2] https://bytecodealliance.org/articles/webassembly-the-update...

[3] https://github.com/bytecodealliance/wasmtime/pull/7285

[4] https://github.com/WebAssembly/shared-everything-threads

Thanks for the question!

Spin could definitely run in more places than what we have pre-built binaries for. Specifically, we could run on all platforms Wasmtime supports today (https://github.com/bytecodealliance/wasmtime/releases/tag/v1...), including RISC and S390X, for example.

And while we have been experimenting a bit with running Spin on RISC, we haven't really had the bandwidth or requirement to build a production build for those yet.

Are you interested in a specific operating system or CPU architecture? Would love to understand your scenario.

> I used to think we'd eventually get to capability based security, but now I see we'll always be stuck with application permission flags, the almost worthless bastard cousin, instead.

My hope is that WASI will introduce capability based security to the mainstream on non-mobile computers [0] - it might just take some time for them to get it right. (And hopefully no half-baked status-quo-reinforcing regressive single—runtime-backed alternatives win in the meantime.)

[0]: https://github.com/bytecodealliance/wasmtime/blob/main/docs/...

WasmTime finished finished the RFC for the implementation details in June: https://github.com/bytecodealliance/wasmtime/issues/5032

[3]: https://github.com/bytecodealliance/wasmtime/pull/2611