Implementing OpenTelemetry in Elixir Applications

In the article, the author shares their journey of enhancing their LiveView Elixir application, which is used for parsing and displaying FIT file data, by integrating OpenTelemetry. The author initially considered plain logging and third-party tools like AppSignal for monitoring, but ultimately chose OpenTelemetry for its vendor agnosticism and seamless integration with the Elixir ecosystem. They guide the reader through the process of adding telemetry spans and events using the OpenTelemetry.Tracer and OpenTelemetry.Span APIs to monitor the parsing of FIT files. They also address an issue with excessive traces during development and demonstrate how to filter these using a custom Elixir sampler or the OTEL Collector. The benefit of OpenTelemetry's standardization is highlighted through its ability to enable services like Honeycomb to immediately analyze and visualize the performance metrics of the application without additional configuration. The author's approach offers insights into building observable systems in Elixir with minimal vendor lock-in and leveraging free tools efficiently.