This project accompanies the Elixir, OpenTelemetry, and the Infamous N+1 article on Fly.io's Phoenix Files blog.

This dives into the topic of observability and specifically the OpenTelemetry project. It uses Elixir and Erlang OpenTelemetry libraries in a Phoenix LiveView application and shows how to debug troublesome database queries. It also shows how the application can be deployed to Fly.io along with Grafana and Tempo so we can store and query our request traces.

Please refer to the article for explanation of what the different parts are and why they are used.

The root of the repo is an Elixir Phoenix application called FlyOtel. It is a LiveView application that demonstrates an efficient and N+1 inneficient way to query the database.

Grafana is the tool used to visualize the application request traces.

Find the files in the fly_apps/grafana directory. It sets up a Dockerfile image, provides minimal config and can be deployed to Fly.io.

Tempo is used to store the trace data that Grafana displays.

Find the files in fly_apps/tempo directory. It sets up a Dockerfile image, provides minimal config and can be deployed to Fly.io.

If you would like to test drive these tools on your own machine, you can use the docker-compose.yml in the local_docker directory and spin up Grafana and Tempo along side your local running instance of the LiveView application.