Heart 💜

A high performance Lua web server with a simple, powerful API. See the full documentation here.

Check out redbean!

If you like Heart then you'll probably love redbean. It's a very similar concept but arguably executed and documented better.

Overview

Heart combines Go's fasthttp with LuaJIT to create an insanely fast Lua web server.

It also comes with a performant key-value store API backed by BadgerDB that can store data both in memory and on disk.

Features

High throughput
Low latency
Fast K/V store
Versioned API
Stable Lua 5.1 VM
Structured logs

Getting Started

Create a Lua file that uses the Heart API

-- main.lua
local app = require('heart.v1')

app.get('/:name', function(ctx)
  return 'Hello, ' .. ctx.pathParam('name') .. '!'
end)

Run Heart with Docker and point it at your Lua docker run -v $(pwd):/root/app -p 3333:3333 hyperspacelogistics/heart:latest app/main.lua
curl localhost:3333/world to see the result
Congratulations you're running a wicked fast Lua server 🎊

Benchmark

Each stack was tasked with rendering {"hello": "world"} through their JSON stack in production mode, if applicable, with logging disabled. wrk was used with the command wrk -t32 -c512 -d30s http://localhost:3333. All benchmarks were performed on a CPU-optimized DigitalOcean droplet that had 32vCPUs and 64 GB of RAM.

Caveats

Global state, like with any parallel web server, is highly discouraged. For performance reasons Heart keeps a pool of Lua state to reuse in subsequent requests. State is reused in a random order and therefore global state that is modified in requests is functionally random in Heart. Be cautious! Static global state is the exception and can generally be treated as safe.