Overview

Datadog tracing libraries provide an implementation of the OpenTelemetry API for instrumenting your code. This means you can maintain vendor-neutral instrumentation of all your services, while still taking advantage of Datadog’s native implementation, features, and products. You can configure it to generate Datadog-style spans and traces to be processed by the Datadog tracing library for your language, and send those to Datadog.

By instrumenting your code with OpenTelemetry API:

• Your code remains free of vendor-specific API calls.
• Your code does not depend on Datadog tracing libraries at compile time (only runtime).

Replace the OpenTelemetry SDK with the Datadog tracing library in the instrumented application, and the traces produced by your running code can be processed, analyzed, and monitored alongside Datadog traces and in Datadog proprietary products.

The Datadog tracing library, when configured as described here, accepts the spans and traces generated by OpenTelemetry-instrumented code, processes the telemetry, and sends it to Datadog. You can use this approach, for example, if your code has already been instrumented with the OpenTelemetry API, or if you want to instrument using the OpenTelemetry API, and you want to gain the benefits of using the Datadog tracing libraries without changing your code.

If you’re looking for a way to instrument your code with OpenTelemetry and then send span data to Datadog without going through the Datadog tracing library, see OpenTelemetry in Datadog.

Requirements and limitations

• Datadog Ruby tracing library dd-trace-rb version 1.9.0 or greater.
• Gem version support 1.1.0 or greater.

The following OpenTelemetry features implemented in the Datadog library as noted:

Configuring OpenTelemetry to use the Datadog tracing library

1. Add your desired manual OpenTelemetry instrumentation to your Ruby code following the OpenTelemetry Ruby Manual Instrumentation documentation. Important! Where those instructions indicate that your code should call the OpenTelemetry SDK, call the Datadog tracing library instead.

2. Add the datadog gem to your Gemfile:

   source 'https://rubygems.org'
   gem 'datadog' # For dd-trace-rb v1.x, use the `ddtrace` gem.
   

3. Install the gem by running bundle install.

4. Add the following lines to your OpenTelemetry configuration file:

   require 'opentelemetry/sdk'
   require 'datadog/opentelemetry'
   

5. Add a configuration block to your application where you can activate integrations and change tracer settings. Without additional configuration here, only code you have instrumented with OpenTelemetry is traced:

   Datadog.configure do |c|
     ...
   end
   

   Using this block you can:

   • Add additional Datadog configuration settings
   • Activate or reconfigure Datadog instrumentation

   OpenTelemetry configuration can be changed separately, using the OpenTelemetry::SDK.configure block.

Datadog combines these OpenTelemetry spans with other Datadog APM spans into a single trace of your application. It supports integration instrumentation and OpenTelemetry Automatic instrumentation also.

Adding span events

You can add span events using the add_event API. This method requires a name parameter and optionally accepts attributes and timestamp parameters. The method creates a new span event with the specified properties and associates it with the corresponding span.

• Name [required]: A string representing the event’s name.
• Attributes [optional]: Zero or more key-value pairs with the following properties:
  • The key must be a non-empty string.
  • The value can be either:
    • A primitive type: string, Boolean, or number.
    • A homogeneous array of primitive type values (for example, an array of strings).
  • Nested arrays and arrays containing elements of different data types are not allowed.
• Timestamp [optional]: A UNIX timestamp representing the event’s occurrence time. Expects seconds(Float).

The following examples demonstrate different ways to add events to a span:

span.add_event('Event With No Attributes')
span.add_event(
  'Event With All Attributes',
  attributes: { 'int_val' => 1, 'string_val' => 'two', 'int_array' => [3, 4], 'string_array' => ['5', '6'], 'bool_array' => [false, true]}
)

Read the OpenTelemetry specification for more information.

Recording exceptions

To record exceptions, use the record_exception API. This method requires an exception parameter and optionally accepts a UNIX timestamp parameter. It creates a new span event that includes standardized exception attributes and associates it with the corresponding span.

The following examples demonstrate different ways to record exceptions:

span.record_exception(
  StandardError.new('Error Message')
)
span.record_exception(
  StandardError.new('Error Message'),
  attributes: { 'status' => 'failed' }
)

Read the OpenTelemetry specification for more information.

Further Reading

Additional helpful documentation, links, and articles:

Explore your services, resources, and tracesDOCUMENTATION Interoperability of OpenTelemetry API and Datadog instrumented tracesDOCUMENTATION