New Relic is a must-have for any production-level web application. It has more features than can possibly be listed here. We will focus on how we can use New Relic to identify performance problems in our application. New Relic provides detailed analytics for each request our application serves. We will be able to see exactly where our application is slow and drill down into why. In this recipe, we will cover the process of installing New Relic in a Rails application. We'll then get a quick tour of the New Relic interface so that we know exactly where to look when diagnosing performance issues.
Before using New Relic, we'll need to install it. This will require us to add the New Relic gem to our application, as well as enable the New Relic add-on in our Heroku application.
To start, let's open a terminal and navigate to our Ruby on Rails application. If we do not have a Rails application to try this out on, we can use the example...