lib/scout_rails/store.rb in scout_rails-1.1.5.pre3 vs lib/scout_rails/store.rb in scout_rails-1.1.5.pre4

@@ -2,10 +2,13 @@
 # of instrumented methods that are being called. It's accessed via +ScoutRails::Agent.instance.store+. 
 class ScoutRails::Store
   
   # Limits the size of the metric hash to prevent a metric explosion. 
   MAX_SIZE = 1000
+
+  # Limit the number of samples that we store metrics with to prevent writing too much data to the layaway file if there are are many processes and many slow samples. 
+  MAX_SAMPLES_TO_STORE_METRICS = 10
   
   attr_accessor :metric_hash
   attr_accessor :transaction_hash
   attr_accessor :stack
   attr_accessor :sample
@@ -191,9 +194,19 @@
       end
     end
     metric_hash
   end
 
+  # Merges samples together, removing transaction sample metrics from samples if the > MAX_SAMPLES_TO_STORE_METRICS
   def merge_samples(old_samples)
+    # need transaction lock here?
     self.samples += old_samples
+    if trim_samples = self.samples[MAX_SAMPLES_TO_STORE_METRICS..-1]
+      ScoutRails::Agent.instance.logger.debug "Trimming metrics from #{trim_samples.size} samples."
+      i = MAX_SAMPLES_TO_STORE_METRICS
+      trim_samples.each do |sample|
+        self.samples[i] = sample.clear_metrics!
+      end
+    end
+    self.samples
   end
 end # class Store
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