Scout APM Sampling

This gem adds sampling feature to scout_apm gem base on the recommendations in Scout APM's documentation.

This gem is designed to work with a Ruby on Rails application.

Once installed, this gem will add before_action and before_perform callbacks to ActionController:Base and ActiveJob::Base which calculates probability and make Scout ignore current transaction if it falls under the threshold.

Add this line to your application's Gemfile:

gem "scout_apm-sampling"

And then execute:

$ bundle install

You can set a sampling rate using SCOUT_APM_SAMPLING_RATE environment variable. This value will be used as the default sampling rate in your application.

export SCOUT_APM_SAMPLING_RATE=0.01 # Sample only 1% of the requests

Note that sampling rate should be a decimal ranging from 0-1:

• 0: captures no requests
• 0.75: captures 75% of the requests
• 1: captures all requests

By default, this gem sets SCOUT_APM_SAMPLING_RATE to 1 to capture all of the requests.

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Please note that this gem is created and maintained by third parties and not affiliated with Scout APM or Zimuth, Inc. All product names and trademarks referred to are the property of their respective owners.

Everyone interacting in the this project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.