Monitoring with Telemetry and Metrics

In Elixir, Telemetry is a powerful, low-level event dispatching library. It helps you understand what's happening inside your running application.

• It's built into Elixir/OTP, making it a standard way to observe systems.
• Think of it as a central nervous system for your app's events.
• It enables you to collect metrics, trace operations, and monitor performance.

It's crucial for building observable and maintainable applications.

Telemetry works by emitting events. An event is a signal that something notable has happened in your application.

• Each event has a unique name (a list of atoms, e.g., [:my_app, :user, :login]).
• Events can carry measurements (numeric values like duration) and metadata (additional context like user ID).
• You don't emit events directly; instead, you use functions that wrap your code.