log sampling config and when ignoring request

lib/scout_apm.rb

@@ -111,6 +111,7 @@ module ScoutApm
 require 'scout_apm/app_server_load'
 
 require 'scout_apm/ignored_uris.rb'
+require 'scout_apm/sampling.rb'
 require 'scout_apm/utils/active_record_metric_name'
 require 'scout_apm/utils/backtrace_parser'
 require 'scout_apm/utils/installed_gems'

lib/scout_apm/agent_context.rb

@@ -91,6 +91,10 @@ def logger
       @logger ||= LoggerFactory.build(config, environment)
     end
 
+    def sampling
+      @sampling ||= ScoutApm::Sampling.new(config)
+    end
+
     def ignored_uris
       @ignored_uris ||= ScoutApm::IgnoredUris.new(config.value('ignore'))
     end

lib/scout_apm/sampling.rb

@@ -9,9 +9,10 @@ def initialize(config)
       @sample_endpoints = individual_sample_to_hash(config.value('sample_endpoints'))
       @ignore_uri_regex = create_uri_regex(config.value('ignore_endpoints'))
       @sample_uri_regex = create_uri_regex(sample_endpoints.keys) if sample_endpoints
-      @ignore_jobs = config.value('ignore_jobs').split(',') if config.value('ignore_jobs')
+      @ignore_jobs = config.value('ignore_jobs')
       @sample_jobs = individual_sample_to_hash(config.value('sample_jobs'))
       # TODO make this safer/smarter
+      logger.info("Sampling Initialized: global_sample_rate: #{global_sample_rate}, sample_endpoints: #{sample_endpoints}, ignore_uri_regex: #{ignore_uri_regex}, sample_uri_regex: #{sample_uri_regex}, ignore_jobs: #{ignore_jobs}, sample_jobs: #{sample_jobs}")
     end
 
     def ignore?(transaction)
@@ -40,7 +41,7 @@ def ignore?(transaction)
     end
 
     def individual_sample_to_hash(sampling_config)
-      return nil if sampling_config.nil?
+      return nil if sampling_config.empty?
       # config looks like ['/foo:50','/bar:100']. parse it into hash of string: integer
       sample_hash = {}
       sampling_config.each do |sample|
@@ -52,7 +53,7 @@ def individual_sample_to_hash(sampling_config)
     end
 
     def create_uri_regex(prefixes)
-      return nil if prefixes.nil?
+      return nil if prefixes.empty?
       regexes = Array(prefixes).
         reject{|prefix| prefix == ""}.
         map {|prefix| %r{\A#{prefix}} }
@@ -81,5 +82,11 @@ def sample?(rate)
       rand * 100 > rate
     end
 
+    private
+
+    def logger
+      ScoutApm::Agent.instance.logger
+    end
+
   end
 end

lib/scout_apm/tracked_request.rb

@@ -303,7 +303,11 @@ def record!
       restore_from_dump! if @agent_context.nil?
 
       # Bail out early if the user asked us to ignore this uri
-      return if @agent_context.ignored_uris.ignore?(annotations[:uri])
+      # return if @agent_context.ignored_uris.ignore?(annotations[:uri])
+      if @agent_context.sampling.ignore?(self)
+        logger.debug("Ignoring request due to sampling")
+        return
+      end
 
       apply_name_override