---
title: "Observing Elixir in Production"
description: "Observer, included with Elixir and Erlang’s BEAM, is a WxWidgets interface that connects in real time to running nodes, showing process trees and state while allowing processes to be killed. This guide uses Fly.io to connect a local Observer to production nodes through a release cookie, a WireGuard tunnel, and a helper script. The example is a multi-region Tic-Tac-Toe application in Frankfurt and Los Angeles; a local IEx session joins the remote cluster, and Observer can connect to either node. Inspecting a live game exposes its GenServer state in Erlang representation. Killing its process immediately starts a replacement with a different PID and leaves other games running, but recovery still requires the player to reload the page or restart game joining."
---

# Observing Elixir in Production

[Fly.io](https://yomu.fyi/company/fly-io) · Jun 14, 2021

**Type:** Tutorial

## Summary

Observer, included with Elixir and Erlang’s BEAM, is a WxWidgets interface that connects in real time to running nodes, showing process trees and state while allowing processes to be killed. This guide uses Fly.io to connect a local Observer to production nodes through a release cookie, a WireGuard tunnel, and a helper script. The example is a multi-region Tic-Tac-Toe application in Frankfurt and Los Angeles; a local IEx session joins the remote cluster, and Observer can connect to either node. Inspecting a live game exposes its GenServer state in Erlang representation. Killing its process immediately starts a replacement with a different PID and leaves other games running, but recovery still requires the player to reload the page or restart game joining.

## Context

Production servers do not have a windowing UI, while Observer’s graphical interface can provide realtime visibility into running BEAM nodes. The post uses this setup to investigate application behavior and test recovery from process failures.

## Approach / What changed

Configure an Elixir release with a supplied cookie, establish a WireGuard VPN connection to the Fly private network, create a script that launches Observer, and use a local IEx session to join the remote cluster. The example deploys a multi-region Tic-Tac-Toe application and inspects or terminates its processes remotely.

## Takeaways

- A local Observer instance can connect to Elixir nodes running across Fly regions through a WireGuard tunnel and a shared release cookie.
- Observer exposes process trees and GenServer state, with state displayed in Erlang’s representation of Elixir data types.
- Killing a game process starts a replacement without affecting other running games, but the player must reload the page or restart game joining to recover.

**Tags:** [Distributed Systems](https://yomu.fyi/topic/distributed-systems), [Elixir](https://yomu.fyi/topic/elixir), [Fly.io](https://yomu.fyi/topic/fly-io), [WireGuard](https://yomu.fyi/topic/wireguard)

- Source: [Fly.io](https://fly.io/blog/observing-elixir-in-production)
- Source URL: https://fly.io/blog/observing-elixir-in-production
- Ingested by Yomu: 2026-09-03T01:25:30.452Z

[Read original post](https://fly.io/blog/observing-elixir-in-production)