The profiler is shipped within Datadog tracing libraries. If you are already using APM to collect traces for your application, you can skip installing the library and go directly to enabling the profiler.

Requirements

The Datadog Profiler requires Ruby 2.3+ (JRuby and TruffleRuby are not supported).

The following operating systems and architectures are supported:

  • Linux (GNU libc) x86-64, aarch64
  • Alpine Linux (musl libc) x86-64, aarch64

You also need either the pkg-config or the pkgconf Linux system utility installed. This utility is available on the software repositories of most Linux distributions. For example:

  • The pkg-config package is available for Homebrew, and Debian- and Ubuntu-based Linux
  • The pkgconf package is available for Arch- and Alpine-based Linux
  • The pkgconf-pkg-config package is available for Fedora- and Red-Hat-based Linux

Continuous Profiler is not supported on serverless platforms, such as AWS Lambda.

Installation

To begin profiling applications:

  1. If you are already using Datadog, upgrade your agent to version 7.20.2+ or 6.20.2+.

  2. Add the ddtrace gem to your Gemfile or gems.rb file:

    gem 'ddtrace', '~> 1.15'
    

    If you’re running a version of ddtrace older than 1.15.0, add the google-protobuf gem (version ~> 3.0) as a dependency.

  3. Install the gems with bundle install.

  4. Enable the profiler:

    export DD_PROFILING_ENABLED=true
    export DD_ENV=prod
    export DD_SERVICE=my-web-app
    export DD_VERSION=1.0.3
    
    Datadog.configure do |c|
      c.profiling.enabled = true
      c.env = 'prod'
      c.service = 'my-web-app'
      c.version = '1.0.3'
    end
    

    Note: For Rails applications, create a config/initializers/datadog.rb file with the code configuration above.

  5. Add the ddtracerb exec command to your Ruby application start command:

    bundle exec ddtracerb exec ruby myapp.rb
    

    Rails example:

    bundle exec ddtracerb exec bin/rails s
    

    Note

    If starting the application via ddtracerb exec is not an option (eg. when using the Phusion Passenger web server), you can alternatively start the profiler by adding the following to your application entry point such as config.ru for a web application:

    require 'datadog/profiling/preload'
    
  6. A minute or two after starting your Ruby application, your profiles will show up on the Datadog APM > Profiler page.

Not sure what to do next?

The Getting Started with Profiler guide takes a sample service with a performance problem and shows you how to use Continuous Profiler to understand and fix the problem.

Further Reading