Server-side WebAssembly

Server-side WebAssembly Speaker: Horacio Gonzalez @LostInBrittany

Horacio Gonzalez @LostInBrittany Spaniard lost in Brittany, developer, dreamer and all-around geek Flutter

OVHcloud: A Global Leader 200k Private cloud VMs running 1 Dedicated IaaS Europe Own 20Tbps Netwok with 35 PoPs 30 Datacenters Hosting capacity : 1.3M Physical Servers 360k Servers already deployed

1.3M Customers in 138 Countries

Did I say WebAssembly? Wasm for the friends…

WebAssembly, what’s that?

A low-level binary format Not a programming language A compilation target

That runs on a stack-based virtual machine A portable binary format that runs on all modern browsers… but also on NodeJS and elsewhere!!

With several key advantages

But above all… WebAssembly is not meant to replace JavaScript

Who is using WebAssembly today? And many more others…

A bit of history Remembering the past to better understand the present

Executing other languages in the browser A long story, with many failures…

2012 - From C to JS: enter emscripten Passing by LLVM pivot

Wait, dude! What’s LLVM? A set of compiler and toolchain technologies

2013 - Generated JS is slow… Let’s use only a strict subset of JS: asm.js Only features adapted to AOT optimization

WebAssembly project Joint effort

Hello W(asm)orld My first WebAssembly program

I don’t want to install a compiler now… Let’s use Wasm Explorer https://mbebenita.github.io/WasmExplorer/

Let’s begin with the a simple function WAT: WebAssembly Text Format Human readable version of the .wasm binary

Download the binary .wasm file Now we need to call it from JS…

Instantiating the Wasm 1. Get the .wasm binary file into an array buffer 2. Compile the bytes into a WebAssembly module 3. Instantiate the WebAssembly module

Instantiating the WASM

Loading the squarer function We instantiate the WASM by loading the wrapping JS

Using it! Directly from the browser console (it’s a simple demo…)

Features of Wasm Why is everybody looking at it?

Near native speed https://medium.com/wasmer/benchmarking-webassembly-runtimes-18497ce0d76e

Highly portable It can be run almost everywhere…

Readable and debuggable Each .wasm file with it .wat companion file

Memory safe & secure Running in a fully sandboxed environment

Accepting many source languages And more and more…

Some constraints Still a young platform

Native WASM types are limited WASM currently has four available types: ● ● ● ● i32: 32-bit integer i64: 64-bit integer f32: 32-bit float f64: 64-bit float Types from languages compiled to WASM are mapped to these types

How can we share data? Using the same data in WASM and JS? Shared linear memory between them, and serializing the data to one Wasm types

Solution is coming: Interface types Beautiful description at: https://hacks.mozilla.org/2019/08/webassembly-interface-types

No outside access By design, communication is done using the shared linear memory only

Solution exists: WASI

Mono-thread and scalar operations only Not the most efficient way…

Solution exists: SIMD

Solutions are coming too: Wasm Threads Threads on Web Workers with shared linear memory

Incoming proposals: Garbage collector And exception handling

Server-side WebAssembly Too good to not to use it

Solomon on Web Assembly

A very interesting feature set

The Bytecode Alliance Taking WASM out of the browser

The Bytecode Alliance

Bytecode Alliance projects

Wasmtime

Cranelift

WebAssembly Micro Runtime

Lucet

Other runtimes Runtimes, runtimes everywhere

Wasmer Run any code* on any client… almost * Languages compiling to WASM

Wasmer

Wasmer ecosystem

Wasm3

And even Wasm over GraalVM!

Some examples IRL? Like companies using these things

Fastly works on the edge of the cloud

Clever Cloud FaaS infrastructure https://www.youtube.com/watch?v=wchehMIsu80

Clever Cloud FaaS Infrastructure Already used in internal projects Able to execute complex loads (neural networks models)

Clever Cloud FaaS Infrastructure Blazing fast