Scout APM sampling

scout.rb

# Apply a sample rate to Scout so it only instruments a portion of requests
# or jobs. Here's an example of how to use it in a controller action or job:
#   ScoutApm::Transaction.use_sample_rate 0.001
module ScoutApm
  module Transaction
    # Set SCOUT_SAMPLING=false to disable sampling. This will send all transactions to Scout,
    # and very quickly use up our monthly transaction limit.
    USE_SAMPLING = ENV["SCOUT_SAMPLING"] != "false"

    def self.use_sample_rate(rate)
      if USE_SAMPLING && rand > rate
        ScoutApm::Transaction.ignore!
      end
    end
  end
end