[DEVOPS-4672] added histogram metric for response time and exposed bucket configura…

build.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+gem build prometheus_exporter.gemspec

lib/prometheus_exporter/server/web_collector.rb

@@ -1,8 +1,16 @@
 # frozen_string_literal: true
 
+require 'yaml'
+
 module PrometheusExporter::Server
   class WebCollector < TypeCollector
     def initialize
+      if ENV["RAIL_PROMETHEUS_EXPORTER_CONFIG"] then
+        @config = YAML.load(File.read(ENV["RAIL_PROMETHEUS_EXPORTER_CONFIG"]))
+      else
+        puts("Could not find env RAIL_PROMETHEUS_EXPORTER_CONFIG. Loading defualt configuration.")
+        @config = {"histogram_buckets"=>[ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5.0, 7.5, 10, 20, 30 ]}
+      end
       @metrics = {}
     end
 
@@ -28,9 +36,16 @@ def ensure_metrics
           "Total HTTP requests from web app."
         )
 
-        @metrics["http_duration_seconds"] = @http_duration_seconds = PrometheusExporter::Metric::Summary.new(
+        # Commenting out request duration summary metrics
+        # @metrics["http_duration_seconds"] = @http_duration_seconds = PrometheusExporter::Metric::Summary.new(
+        #   "http_duration_seconds",
+        #   "Time spent in HTTP reqs in seconds."
+        # )
+
+        @metrics["http_duration_seconds"] = @http_duration_seconds = PrometheusExporter::Metric::Histogram.new(
           "http_duration_seconds",
-          "Time spent in HTTP reqs in seconds."
+          "Time spent in HTTP reqs in seconds.",
+          opts={:buckets=>@config["histogram_buckets"]}
         )
 
         @metrics["http_redis_duration_seconds"] = @http_redis_duration_seconds = PrometheusExporter::Metric::Summary.new(
@@ -50,10 +65,20 @@ def ensure_metrics
       end
     end
 
+    def replace_digits_in_controller(controller)
+      if controller
+        controller = controller.gsub(/\d+/, "digit")
+      end
+      controller
+    end
+
     def observe(obj)
+      obj['controller'] = replace_digits_in_controller(obj['controller'])
+
       default_labels = {
-        controller: obj['controller'] || 'other',
-        action: obj['action'] || 'other'
+        request_url: obj['controller'] || 'other',
+        action: obj['action'] || 'other',
+        status_code: obj["status"]
       }
       custom_labels = obj['custom_labels']
       labels = custom_labels.nil? ? default_labels : default_labels.merge(custom_labels)

lib/prometheus_exporter/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module PrometheusExporter
-  VERSION = '0.5.1'
+  VERSION = '0.5.1.db'
 end