Partition job_queue_duration_seconds with jobs_running_for_project

app/services/ci/register_job_service.rb

@@ -4,6 +4,9 @@ module Ci
   class RegisterJobService
     attr_reader :runner
 
+    JOB_QUEUE_DURATION_SECONDS_BUCKETS = [1, 3, 10, 30].freeze
+    JOBS_RUNNING_FOR_PROJECT_MAX_BUCKET = 5.freeze
+
     Result = Struct.new(:build, :valid?)
 
     def initialize(runner)
@@ -104,10 +107,22 @@ module Ci
     end
 
     def register_success(job)
-      job_queue_duration_seconds.observe({ shared_runner: @runner.shared? }, Time.now - job.created_at)
+      labels = { shared_runner: runner.shared?,
+                 jobs_running_for_project: jobs_running_for_project(job) }
+
+      job_queue_duration_seconds.observe(labels, Time.now - job.queued_at)
       attempt_counter.increment
     end
 
+    def jobs_running_for_project(job)
+      return '+Inf' unless runner.shared?
+
+      # excluding currently started job
+      running_jobs_count = job.project.builds.running.where(runner: Ci::Runner.shared)
+                              .limit(JOBS_RUNNING_FOR_PROJECT_MAX_BUCKET + 1).count - 1
+      running_jobs_count < JOBS_RUNNING_FOR_PROJECT_MAX_BUCKET ? running_jobs_count : "#{JOBS_RUNNING_FOR_PROJECT_MAX_BUCKET}+"
+    end
+
     def failed_attempt_counter
       @failed_attempt_counter ||= Gitlab::Metrics.counter(:job_register_attempts_failed_total, "Counts the times a runner tries to register a job")
     end
@@ -117,7 +132,7 @@ module Ci
     end
 
     def job_queue_duration_seconds
-      @job_queue_duration_seconds ||= Gitlab::Metrics.histogram(:job_queue_duration_seconds, 'Request handling execution time')
+      @job_queue_duration_seconds ||= Gitlab::Metrics.histogram(:job_queue_duration_seconds, 'Request handling execution time', {}, JOB_QUEUE_DURATION_SECONDS_BUCKETS)
     end
   end
 end

spec/factories/ci/builds.rb

@@ -62,6 +62,7 @@ FactoryBot.define do
     end
 
     trait :pending do
+      queued_at 'Di 29. Okt 09:50:59 CET 2013'
       status 'pending'
     end
 

spec/services/ci/register_job_service_spec.rb

@@ -370,10 +370,89 @@ module Ci
           it_behaves_like 'validation is not active'
         end
       end
+    end
+
+    describe '#register_success' do
+      let!(:current_time) { Time.new(2018, 4, 5, 14, 0, 0) }
+      let!(:attempt_counter) { double('Gitlab::Metrics::NullMetric') }
+      let!(:job_queue_duration_seconds) { double('Gitlab::Metrics::NullMetric') }
+
+      before do
+        allow(Time).to receive(:now).and_return(current_time)
+
+        # Stub defaults for any metrics other than the ones we're testing
+        allow(Gitlab::Metrics).to receive(:counter)
+                                    .with(any_args)
+                                    .and_return(Gitlab::Metrics::NullMetric.instance)
+        allow(Gitlab::Metrics).to receive(:histogram)
+                                    .with(any_args)
+                                    .and_return(Gitlab::Metrics::NullMetric.instance)
+
+        # Stub tested metrics
+        allow(Gitlab::Metrics).to receive(:counter)
+                                    .with(:job_register_attempts_total, anything)
+                                    .and_return(attempt_counter)
+        allow(Gitlab::Metrics).to receive(:histogram)
+                                    .with(:job_queue_duration_seconds, anything, anything, anything)
+                                    .and_return(job_queue_duration_seconds)
+
+        project.update(shared_runners_enabled: true)
+        pending_job.update(created_at: current_time - 3600, queued_at: current_time - 1800)
+      end
+
+      shared_examples 'metrics collector' do
+        it 'increments attempt counter' do
+          allow(job_queue_duration_seconds).to receive(:observe)
+          expect(attempt_counter).to receive(:increment)
+
+          execute(runner)
+        end
+
+        it 'counts job queuing time histogram with expected labels' do
+          allow(attempt_counter).to receive(:increment)
+          expect(job_queue_duration_seconds).to receive(:observe)
+            .with({ shared_runner: expected_shared_runner,
+                    jobs_running_for_project: expected_jobs_running_for_project_first_job }, 1800)
+
+          execute(runner)
+        end
+
+        context 'when project already has running jobs' do
+          let!(:build2) { create( :ci_build, :running, pipeline: pipeline, runner: shared_runner) }
+          let!(:build3) { create( :ci_build, :running, pipeline: pipeline, runner: shared_runner) }
+
+          it 'counts job queuing time histogram with expected labels' do
+            allow(attempt_counter).to receive(:increment)
+            expect(job_queue_duration_seconds).to receive(:observe)
+              .with({ shared_runner: expected_shared_runner,
+                      jobs_running_for_project: expected_jobs_running_for_project_third_job }, 1800)
+
+            execute(runner)
+          end
+        end
+      end
+
+      context 'when shared runner is used' do
+        let(:runner) { shared_runner }
+        let(:expected_shared_runner) { true }
+        let(:expected_jobs_running_for_project_first_job) { 0 }
+        let(:expected_jobs_running_for_project_third_job) { 2 }
+
+        it_behaves_like 'metrics collector'
+      end
+
+      context 'when specific runner is used' do
+        let(:runner) { specific_runner }
+        let(:expected_shared_runner) { false }
+        let(:expected_jobs_running_for_project_first_job) { '+Inf' }
+        let(:expected_jobs_running_for_project_third_job) { '+Inf' }
+
+        it_behaves_like 'metrics collector'
+      end
+    end
 
     def execute(runner)
       described_class.new(runner).execute.build
     end
   end
-  end
 end