Ruby

Overview

Instrumenting your Ruby application to generate traces, logs, and metrics is a powerful way to gain deep insights into its behavior and performance. For example, to get a clearer picture of your Ruby on Rails apps and the database statements generated through Active Record. By adding instrumentation, you enable your application to emit valuable data that can be used for monitoring, troubleshooting, and optimization.

Dash0 supports automatic instrumentation of Ruby applications through OpenTelemetry's open-source and vendor-agnostic gems.

Use Cases

• Understand outgoing and incoming HTTP requests through traces and metrics. Allowing drill-downs to the database level.
• You can see which database statements were executed and how long they took, which gives you valuable data to optimize your applications.
• Reveal (uncaught) errors and the context in which they happened.
• Get deep visibility into your Ruby on Rails apps.

Install

OpenTelemetry comes with ready-made auto-instrumentation gems for Ruby that will kickstart your observability journey. Let's start by installing them:

Initialize the OTel SDK

The OpenTelemetry SDK needs to be initialized on startup before your application's and framework's code. Execute the following code as the first thing within your app. Within Rails you can achieve this by putting this code into a file called config/initializers/opentelemetry.rb.

Configure

The auto-instrumentation in OpenTelemetry can be configured using environment variables.

1. Specify the application service name:

Replace my-first-observable-ruby-service with a meaningful name that identifies your application.

2. Set up the data export endpoint and authorization token:

Note: You can specify which dataset to send data to by adding the Dash0-Dataset header. For example:

For more information, see the dataset documentation.

Kubernetes Setup

In case you are not using the Dash0 operator for Kubernetes to deploy your application, you should extend the OpenTelemetry resource attributes to include the Pod UID. This is important to merge the resources between logs,traces and metrics. You can do this by adding the following environment variables to your deployment:

This will add the k8s.pod.name and k8s.pod.uid attributes to the OpenTelemetry resource attributes, which will be included in all telemetry data sent to Dash0. To read more about resource equality and merging, please refer to the Dash0 docs.

In order to learn more about the importance of resource attributes read the blog post OpenTelemetry resource attributes: Best practices for Kubernetes

Supported libraries and frameworks

To understand which libraries are automatically instrumented by this package, please refer to the opentelemetry-ruby-contrib.