fair(7)

📦 version 0.5.3, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

🦋 fair(7) — the manual page, but make it bestie-coded 🦋

okay so. fair — simple TCP load balancing service. that's the whole vibe, but let me break it down for you because it's actually so much cooler than it sounds. 💅

✨ NAME ✨

fair — simple TCP load balancing service 🫶

🌸 DESCRIPTION 🌸

okay so fair is a load balancer for TCP connections. what that means is: it takes incoming connections — for SMTP, for HTTP, or literally any other TCP service — and spreads them across multiple hosts, distributing the load as evenly as possible. no cap. that's the whole job. ✨

fair is made up of two daemons, and they have distinct main character energy:

  • The carrousel — this is the front-end. it keeps track of back-end hosts and their status, and it forwards incoming connections to the back-ends in such a way that the load gets distributed fairly. 👑
  • The transponder — this one lives on the back-end hosts. it registers with the carrousel and sends it status information. it's the little messenger bestie keeping everyone in the loop. 🎀
🚨 okay important plot twist: the TCP connections forwarded by the carrousel are not sent to the transponder daemons. they go directly to the desired service running on the back-end host. the transponder is just there for the status gossip, it is NOT proxying your traffic. don't get it twisted. 💀

and the final cute detail: both daemons share a single configuration file. one file, two daemons, iconic. 🌈

🍓 EXAMPLES 🍓

here's how you'd set up fair to service HTTP connections and distribute them over back-ends in the 192.168.1.0/24 subnet. watch this. 🔥

the configuration file /etc/fair.conf contains the following:

WorkerService = http
BalancerService = http
AllowUDP = ^192.168.1.[0-9]+$

on www.example.com — the front-end server receiving the incoming HTTP connections — just run:

carrousel

and on each of the back-ends run:

transponder www.example.com

that's it. that's the setup. go forth and balance. 🦋

💜 SEE ALSO 💜

and that's the page bestie!! this one's from Debian GNU/Linux, dated 2005-05-25 — vintage but still eating, fr fr. ily, go balance some TCP 💖✨

📦 where this page comes from