Adopting Elixir

Instrumenting Ecto

The metrics in the virtual machine are important building blocks, but they do not always tell what you need to know about the rest of your application. Moving up one level, let’s learn how to get data from the database layer. While you might find it comforting that the metrics system will tell you when your database queries are waiting for more than a second in the connection pool queue, it is better to know this will happen before you ever put your system into production. Ecto^[113] is the best place to start. To get detailed metrics, hook into the Ecto logging API. Let’s see how that works using our sample application.

First, we’ll generate some blog code to test. Use Phoenix generators to build a context that interacts with ...