Using Reuse Port for Multiple Kemal Processes

require "kemal"

get "/" do
  "Reusing port 3000"
end

Kemal.run do |config|
  server = config.server.not_nil!
  server.bind_tcp "0.0.0.0", 3000, reuse_port: true
end

You can use the following script to spawn multiple Kemal processes according to your CPU cores.

#!/bin/bash

for i in $(seq 1 $(nproc --all)); do
  ./app
done

wait

Important: This is for demonstration purpose only. You should use a mature process manager / monitor for production.

Source Code