New Relic is a performance management system, developed by New Relic, Inc (http://www.newrelic.com). It provides you with deep information about the performance of your Rails or Ruby application as it runs in production. The New Relic Ruby Agent is dual-purposed as a either a Gem or a Rails plugin, hosted on github.
The New Relic Ruby Agent runs in one of two modes:
Production Mode Low overhead instrumentation that captures detailed information on your application running in production and transmits them to newrelic.com where you can monitor them in real time.
Developer Mode
A Rack middleware that maps /newrelic to an application for showing
detailed performance metrics on a page by page basis. Installed
automatically in Rails applications.
An up-to-date list of Ruby versions and frameworks for the latest agent can be found on our docs site.
You can also monitor non-web applications. Refer to the "Other Environments" section under "Getting Started".
We welcome code contributions (in the form of pull requests) from our user community. Before submitting a pull request please review GUIDELINES_FOR_CONTRIBUTING.
Following these helps us efficiently review and incorporate your contribution and avoid breaking your code with future changes to the agent.
Add the Ruby Agent to your project's Gemfile.
gem 'newrelic_rpm'
To monitor your applications in production, create an account at http://newrelic.com/ . There you can sign up for a free Lite account or one of our paid subscriptions.
Once you receive the welcome email with a license key and
newrelic.yml file, you can copy the newrelic.yml file into your app config
directory OR can generate the file manually with command:
newrelic install --license_key="YOUR_KEY" "My application"
The initial configuration is done in the newrelic.yml file. This file
is by default read from the config directory of the application root
and is subsequently searched for in the application root directory,
and then in a ~/.newrelic directory. Once you're up and running you can
enable Server Side Config and manage your newrelic configuration from the web
UI.
You can install the agent as a Gem:
For Bundler:
Add the following line to your Gemfile:
gem 'newrelic_rpm'
For Rails 2.x without Bundler:
edit environment.rb and add to the initalizer block:
config.gem "newrelic_rpm"
To use the Ruby Agent with a Sinatra app, add
require 'newrelic_rpm'
in your Sinatra app, below the Sinatra require directive.
Then make sure you set RACK_ENV to the environment corresponding to the
configuration definitions in the newrelic.yml file; e.g., development,
staging, production, etc.
To use Developer Mode in Sinatra, add NewRelic::Rack::DeveloperMode to
the middleware stack. See the config.ru sample below.
You can use the Ruby Agent to monitor any Ruby application. Add
require 'newrelic_rpm'
to your startup sequence and then manually start the agent using
NewRelic::Agent.manual_start
For information about instrumenting pure Rack applications, see our Rack middlewares documentation.
Refer to the New Relic's Docs for details on how to monitor other web frameworks, background jobs, and daemons.
The Ruby Agent provides an API that allows custom instrumentation of additional frameworks. You can find a list of community created intrumentation plugins (e.g. newrelic-redis) in the extends_newrelic_rpm project.
When running the Developer Mode, the Ruby Agent will track the performance of every HTTP request serviced by your application, and store in memory this information for the last 100 HTTP transactions.
To view this performance information, including detailed SQL statement
analysis, open /newrelic in your web application. For instance if
you are running mongrel or thin on port 3000, enter the following into
your browser:
http://localhost:3000/newrelic
Developer Mode is only initialized if the developer_mode setting in
the newrelic.yml file is set to true. By default, it is turned off in
all environments but development.
Developer Mode is available automatically in Rails Applications based
on Rails 2.3 and later. No additional configuration is required. When
your application starts and developer_mode is enabled, the Ruby
Agent injects a middleware into your Rails middleware stack.
For earlier versions of Rails that support Rack, you can use
a config.ru as below.
Developer Mode is available for any Rack based application such as Sinatra by installing the NewRelic::Rack::DeveloperMode middleware. This middleware passes all requests that do not start with /newrelic.
Here's an example entry for Developer Mode in a config.ru file:
require 'new_relic/rack/developer_mode'
use NewRelic::Rack::DeveloperMode
When your application runs in the production environment, the New Relic agent runs in production mode. It connects to the New Relic service and sends deep performance data to the UI for your analysis. To view this data, log in to http://rpm.newrelic.com.
NOTE: You must have a valid account and license key to view this data online. Refer to instructions in Getting Started.
The Ruby Agent supports recording deployments in New Relic via a command line tool or Capistrano recipes. For more information on these features see our deployment documentation for more information.
You can find more detailed documentation on our website, and specifically in the Ruby category.
If you can't find what you're looking for there, reach out to us on our support site or our community forum and we'll be happy to help you.
Also available is community support on IRC: we generally use #newrelic on irc.freenode.net
Find a bug? Contact us via support.newrelic.com, or email [email protected].
Thank you, and may your application scale to infinity plus one.
Lew Cirne, Founder and CEO
New Relic, Inc.