collect_by_queue added as optional argument to GoodJob#Start

Author: benngarcia

lib/prometheus_exporter/instrumentation/good_job.rb

@@ -3,27 +3,32 @@
 # collects stats from GoodJob
 module PrometheusExporter::Instrumentation
   class GoodJob < PeriodicStats
-    def self.start(client: nil, frequency: 30)
+    COUNT_BY_QUEUE = ->(collection) { collection.group(:queue_name).size }
+    COUNT_ALL = ->(collection) { collection.size }
+
+    def self.start(client: nil, frequency: 30, collect_by_queue: false)
       good_job_collector = new
       client ||= PrometheusExporter::Client.default
 
       worker_loop do
-        client.send_json(good_job_collector.collect)
+        client.send_json(good_job_collector.collect(collect_by_queue))
       end
 
       super
     end
 
-    def collect
+    def collect(by_queue = false)
+      count_method = by_queue ? COUNT_BY_QUEUE : COUNT_ALL
       {
         type: "good_job",
-        scheduled: ::GoodJob::Job.scheduled.size,
-        retried: ::GoodJob::Job.retried.size,
-        queued: ::GoodJob::Job.queued.size,
-        running: ::GoodJob::Job.running.size,
-        finished: ::GoodJob::Job.finished.size,
-        succeeded: ::GoodJob::Job.succeeded.size,
-        discarded: ::GoodJob::Job.discarded.size
+        by_queue: by_queue,
+        scheduled: ::GoodJob::Job.scheduled.yield_self(&count_method),
+        retried: ::GoodJob::Job.retried.yield_self(&count_method),
+        queued: ::GoodJob::Job.queued.yield_self(&count_method),
+        running: ::GoodJob::Job.running.yield_self(&count_method),
+        finished: ::GoodJob::Job.finished.yield_self(&count_method),
+        succeeded: ::GoodJob::Job.succeeded.yield_self(&count_method),
+        discarded: ::GoodJob::Job.discarded.yield_self(&count_method)
       }
     end
   end

lib/prometheus_exporter/server/good_job_collector.rb

@@ -33,7 +33,14 @@ def metrics
 
           if value
             gauge = gauges[name] ||= PrometheusExporter::Metric::Gauge.new("good_job_#{name}", help)
-            gauge.observe(value, labels)
+
+            if metric["by_queue"]
+              value.each do |queue_name, count|
+                gauge.observe(count, labels.merge(queue_name: queue_name))
+              end
+            else
+              gauge.observe(value, labels)
+            end
           end
         end
       end