Add graceful timeout handling for analytics

Analytics endpoint should return graceful error message
when it fails with query timeout

app/controllers/concerns/graceful_timeout_handling.rb

+# frozen_string_literal: true
+
+module GracefulTimeoutHandling
+  extend ActiveSupport::Concern
+
+  included do
+    rescue_from ActiveRecord::QueryCanceled do |exception|
+      raise exception unless request.format.json?
+
+      log_exception(exception)
+
+      render json: { error: _('There is too much data to calculate. Please change your selection.') }
+    end
+  end
+end

app/controllers/projects/cycle_analytics/events_controller.rb

@@ -4,6 +4,7 @@ module Projects
   module CycleAnalytics
     class EventsController < Projects::ApplicationController
       include CycleAnalyticsParams
+      include GracefulTimeoutHandling
 
       before_action :authorize_read_cycle_analytics!
       before_action :authorize_read_build!, only: [:test, :staging]

app/controllers/projects/cycle_analytics_controller.rb

@@ -5,6 +5,7 @@ class Projects::CycleAnalyticsController < Projects::ApplicationController
   include ActionView::Helpers::TextHelper
   include CycleAnalyticsParams
   include Analytics::UniqueVisitsHelper
+  include GracefulTimeoutHandling
 
   before_action :whitelist_query_limiting, only: [:show]
   before_action :authorize_read_cycle_analytics!

changelogs/unreleased/225405-graceful-timeout-handling-for-analytics.yml

+---
+title: Add graceful timeout handling for analytics
+merge_request: 36811
+author:
+type: fixed

ee/app/controllers/analytics/application_controller.rb

@@ -3,6 +3,7 @@
 module Analytics
   class ApplicationController < ::ApplicationController
     include RoutableActions
+    include GracefulTimeoutHandling
 
     layout 'analytics'
 

ee/spec/controllers/analytics/analytics_controller_spec.rb

@@ -28,4 +28,6 @@ RSpec.describe Analytics::AnalyticsController do
       end
     end
   end
+
+  include_examples GracefulTimeoutHandling
 end

locale/gitlab.pot

@@ -23684,6 +23684,9 @@ msgstr ""
 msgid "There is no data available. Please change your selection."
 msgstr ""
 
+msgid "There is too much data to calculate. Please change your selection."
+msgstr ""
+
 msgid "There was a problem communicating with your device."
 msgstr ""
 

spec/controllers/concerns/graceful_timeout_handling_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GracefulTimeoutHandling, type: :controller do
+  controller(ApplicationController) do
+    include GracefulTimeoutHandling
+
+    skip_before_action :authenticate_user!
+
+    def index
+      raise ActiveRecord::QueryCanceled.new
+    end
+  end
+
+  context 'for json request' do
+    subject { get :index, format: :json }
+
+    it 'renders graceful error message' do
+      subject
+
+      expect(json_response['error']).to eq(_('There is too much data to calculate. Please change your selection.'))
+      expect(response.code).to eq '200'
+    end
+
+    it 'logs exception' do
+      expect(Gitlab::ErrorTracking).to receive(:track_exception).with(kind_of(ActiveRecord::QueryCanceled))
+
+      subject
+    end
+  end
+
+  context 'for html request' do
+    subject { get :index, format: :html }
+
+    it 'has no effect' do
+      expect do
+        subject
+      end.to raise_error(ActiveRecord::QueryCanceled)
+    end
+  end
+end

spec/controllers/projects/cycle_analytics/events_controller_spec.rb

@@ -57,6 +57,8 @@ RSpec.describe Projects::CycleAnalytics::EventsController do
     end
   end
 
+  include_examples GracefulTimeoutHandling
+
   def get_issue(additional_params: {})
     params = additional_params.merge(namespace_id: project.namespace, project_id: project)
     get(:issue, params: params, format: :json)

spec/controllers/projects/cycle_analytics_controller_spec.rb

@@ -67,4 +67,6 @@ RSpec.describe Projects::CycleAnalyticsController do
       end
     end
   end
+
+  include_examples GracefulTimeoutHandling
 end

spec/support/shared_examples/controllers/concerns/graceful_timeout_handling_shared_examples.rb

+# frozen_string_literal: true
+
+RSpec.shared_examples GracefulTimeoutHandling do
+  it 'includes GracefulTimeoutHandling' do
+    expect(controller).to be_a(GracefulTimeoutHandling)
+  end
+end