Preload associations in Ci::Pipeline#cancel_running

app/models/ci/pipeline.rb

@@ -584,10 +584,18 @@ module Ci
     end
 
     def cancel_running(retries: nil)
-      retry_optimistic_lock(cancelable_statuses, retries, name: 'ci_pipeline_cancel_running') do |cancelable|
-        cancelable.find_each do |job|
-          yield(job) if block_given?
-          job.cancel
+      commit_status_relations = [:project, :pipeline]
+      ci_build_relations = [:deployment, :taggings]
+
+      retry_optimistic_lock(cancelable_statuses, retries, name: 'ci_pipeline_cancel_running') do |cancelables|
+        cancelables.find_in_batches do |batch|
+          ActiveRecord::Associations::Preloader.new.preload(batch, commit_status_relations)
+          ActiveRecord::Associations::Preloader.new.preload(batch.select { |job| job.is_a?(Ci::Build) }, ci_build_relations)
+
+          batch.each do |job|
+            yield(job) if block_given?
+            job.cancel
+          end
         end
       end
     end

changelogs/unreleased/21098-reducing-cancel-sql-queries.yml

+---
+title: Preload associations in Ci::Pipeline#cancel_running
+merge_request: 58484
+author:
+type: performance

spec/models/ci/pipeline_spec.rb

@@ -2635,6 +2635,37 @@ RSpec.describe Ci::Pipeline, :mailer, factory_default: :keep do
         expect(latest_status).to eq %w(canceled canceled)
       end
     end
+
+    context 'preloading relations' do
+      let(:pipeline1) { create(:ci_empty_pipeline, :created) }
+      let(:pipeline2) { create(:ci_empty_pipeline, :created) }
+
+      before do
+        create(:ci_build, :pending, pipeline: pipeline1)
+        create(:generic_commit_status, :pending, pipeline: pipeline1)
+
+        create(:ci_build, :pending, pipeline: pipeline2)
+        create(:ci_build, :pending, pipeline: pipeline2)
+        create(:generic_commit_status, :pending, pipeline: pipeline2)
+        create(:generic_commit_status, :pending, pipeline: pipeline2)
+        create(:generic_commit_status, :pending, pipeline: pipeline2)
+      end
+
+      it 'preloads relations for each build to avoid N+1 queries' do
+        control1 = ActiveRecord::QueryRecorder.new do
+          pipeline1.cancel_running
+        end
+
+        control2 = ActiveRecord::QueryRecorder.new do
+          pipeline2.cancel_running
+        end
+
+        extra_update_queries = 3 # transition ... => :canceled
+        extra_generic_commit_status_validation_queries = 2 # name_uniqueness_across_types
+
+        expect(control2.count).to eq(control1.count + extra_update_queries + extra_generic_commit_status_validation_queries)
+      end
+    end
   end
 
   describe '#retry_failed' do