Merge branch 'fp-reduce-queries-when-ticking-runner-queue' into 'master'

Reduce queries when ticking runner queue [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!55496

app/models/ci/runner.rb

@@ -253,9 +253,10 @@ module Ci
     end
 
     def can_pick?(build)
-      return false if self.ref_protected? && !build.protected?
-
-      assignable_for?(build.project_id) && accepting_tags?(build)
+      #  Run `matches_build?` checks before, since they are cheaper than
+      # `assignable_for?`.
+      #
+      matches_build?(build) && assignable_for?(build.project_id)
     end
 
     def only_for?(project)
@@ -305,8 +306,10 @@ module Ci
     end
 
     def pick_build!(build)
-      if can_pick?(build)
-        tick_runner_queue
+      if Feature.enabled?(:ci_reduce_queries_when_ticking_runner_queue, self, default_enabled: :yaml)
+        tick_runner_queue if matches_build?(build)
+      else
+        tick_runner_queue if can_pick?(build)
       end
     end
 
@@ -370,6 +373,13 @@ module Ci
       end
     end
 
+    # TODO: choose a better name and consider splitting this method into two
+    def matches_build?(build)
+      return false if self.ref_protected? && !build.protected?
+
+      accepting_tags?(build)
+    end
+
     def accepting_tags?(build)
       (run_untagged? || build.has_tags?) && (build.tag_list - tag_list).empty?
     end

changelogs/unreleased/fp-reduce-queries-when-ticking-runner-queue.yml

+---
+title: Reduce queries when ticking runner queue
+merge_request: 55496
+author:
+type: performance

config/feature_flags/development/ci_reduce_queries_when_ticking_runner_queue.yml

+---
+name: ci_reduce_queries_when_ticking_runner_queue
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/55496
+rollout_issue_url: 
+milestone: '13.10'
+type: development
+group: group::continuous integration
+default_enabled: false

spec/models/ci/runner_spec.rb

@@ -842,27 +842,50 @@ RSpec.describe Ci::Runner do
   end
 
   describe '#pick_build!' do
+    let(:build) { create(:ci_build) }
+    let(:runner) { create(:ci_runner) }
+
     context 'runner can pick the build' do
       it 'calls #tick_runner_queue' do
-        ci_build = build(:ci_build)
-        runner = build(:ci_runner)
-        allow(runner).to receive(:can_pick?).with(ci_build).and_return(true)
-
         expect(runner).to receive(:tick_runner_queue)
 
-        runner.pick_build!(ci_build)
+        runner.pick_build!(build)
       end
     end
 
     context 'runner cannot pick the build' do
-      it 'does not call #tick_runner_queue' do
-        ci_build = build(:ci_build)
-        runner = build(:ci_runner)
-        allow(runner).to receive(:can_pick?).with(ci_build).and_return(false)
+      before do
+        build.tag_list = [:docker]
+      end
 
+      it 'does not call #tick_runner_queue' do
         expect(runner).not_to receive(:tick_runner_queue)
 
-        runner.pick_build!(ci_build)
+        runner.pick_build!(build)
+      end
+    end
+
+    context 'build picking improvement enabled' do
+      before do
+        stub_feature_flags(ci_reduce_queries_when_ticking_runner_queue: true)
+      end
+
+      it 'does not check if the build is assignable to a runner' do
+        expect(runner).not_to receive(:can_pick?)
+
+        runner.pick_build!(build)
+      end
+    end
+
+    context 'build picking improvement disabled' do
+      before do
+        stub_feature_flags(ci_reduce_queries_when_ticking_runner_queue: false)
+      end
+
+      it 'checks if the build is assignable to a runner' do
+        expect(runner).to receive(:can_pick?).and_call_original
+
+        runner.pick_build!(build)
       end
     end
   end

spec/services/ci/update_build_queue_service_spec.rb

@@ -26,6 +26,24 @@ RSpec.describe Ci::UpdateBuildQueueService do
       end
 
       it_behaves_like 'refreshes runner'
+
+      it 'avoids running redundant queries' do
+        expect(Ci::Runner).not_to receive(:owned_or_instance_wide)
+
+        subject.execute(build)
+      end
+
+      context 'when feature flag ci_reduce_queries_when_ticking_runner_queue is disabled' do
+        before do
+          stub_feature_flags(ci_reduce_queries_when_ticking_runner_queue: false)
+        end
+
+        it 'runs redundant queries using `owned_or_instance_wide` scope' do
+          expect(Ci::Runner).to receive(:owned_or_instance_wide).and_call_original
+
+          subject.execute(build)
+        end
+      end
     end
   end