Log Optimistic Locks with retries

Use structured logging for gathering info on Optimistic Locks which were
not able to succeed without retries.

app/models/ci/pipeline.rb

@@ -573,7 +573,7 @@ module Ci
     end
 
     def cancel_running(retries: nil)
-      retry_optimistic_lock(cancelable_statuses, retries) do |cancelable|
+      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
@@ -744,7 +744,7 @@ module Ci
     end
 
     def set_status(new_status)
-      retry_optimistic_lock(self) do
+      retry_optimistic_lock(self, name: 'ci_pipeline_set_status') do
         case new_status
         when 'created' then nil
         when 'waiting_for_resource' then request_resource

app/models/ci/ref.rb

@@ -62,7 +62,7 @@ module Ci
     end
 
     def update_status_by!(pipeline)
-      retry_lock(self) do
+      retry_lock(self, name: 'ci_ref_update_status_by') do
         next unless last_finished_pipeline_id == pipeline.id
 
         case pipeline.status

app/models/ci/stage.rb

@@ -84,7 +84,7 @@ module Ci
     end
 
     def set_status(new_status)
-      retry_optimistic_lock(self) do
+      retry_optimistic_lock(self, name: 'ci_stage_set_status') do
         case new_status
         when 'created' then nil
         when 'waiting_for_resource' then request_resource

app/models/environment.rb

@@ -242,7 +242,7 @@ class Environment < ApplicationRecord
   def cancel_deployment_jobs!
     jobs = active_deployments.with_deployable
     jobs.each do |deployment|
-      Gitlab::OptimisticLocking.retry_lock(deployment.deployable) do |deployable|
+      Gitlab::OptimisticLocking.retry_lock(deployment.deployable, name: 'environment_cancel_deployment_jobs') do |deployable|
         deployable.cancel! if deployable&.cancelable?
       end
     rescue => e

app/services/ci/create_downstream_pipeline_service.rb

@@ -43,7 +43,7 @@ module Ci
     private
 
     def update_bridge_status!(bridge, pipeline)
-      Gitlab::OptimisticLocking.retry_lock(bridge) do |subject|
+      Gitlab::OptimisticLocking.retry_lock(bridge, name: 'create_downstream_pipeline_update_bridge_status') do |subject|
         if pipeline.created_successfully?
           # If bridge uses `strategy:depend` we leave it running
           # and update the status when the downstream pipeline completes.

app/services/ci/pipeline_processing/atomic_processing_service.rb

@@ -80,7 +80,7 @@ module Ci
         return unless Ci::HasStatus::COMPLETED_STATUSES.include?(status)
 
         # transition status if possible
-        Gitlab::OptimisticLocking.retry_lock(processable) do |subject|
+        Gitlab::OptimisticLocking.retry_lock(processable, name: 'atomic_processing_update_processable') do |subject|
           Ci::ProcessBuildService.new(project, subject.user)
             .execute(subject, status)
 

app/services/ci/register_job_service.rb

@@ -152,7 +152,7 @@ module Ci
     end
 
     def scheduler_failure!(build)
-      Gitlab::OptimisticLocking.retry_lock(build, 3) do |subject|
+      Gitlab::OptimisticLocking.retry_lock(build, 3, name: 'register_job_scheduler_failure') do |subject|
         subject.drop!(:scheduler_failure)
       end
     rescue => ex

app/services/ci/retry_build_service.rb

@@ -19,7 +19,7 @@ module Ci
         mark_subsequent_stages_as_processable(build)
         build.pipeline.reset_ancestor_bridges!
 
-        Gitlab::OptimisticLocking.retry_lock(new_build, &:enqueue)
+        Gitlab::OptimisticLocking.retry_lock(new_build, name: 'retry_build', &:enqueue)
 
         MergeRequests::AddTodoWhenBuildFailsService
           .new(project, current_user)
@@ -68,7 +68,7 @@ module Ci
 
     def mark_subsequent_stages_as_processable(build)
       build.pipeline.processables.skipped.after_stage(build.stage_idx).find_each do |skipped|
-        retry_optimistic_lock(skipped) { |build| build.process(current_user) }
+        retry_optimistic_lock(skipped, name: 'ci_retry_build_mark_subsequent_stages') { |build| build.process(current_user) }
       end
     end
   end

app/services/ci/retry_pipeline_service.rb

@@ -23,7 +23,7 @@ module Ci
       end
 
       pipeline.builds.latest.skipped.find_each do |skipped|
-        retry_optimistic_lock(skipped) { |build| build.process(current_user) }
+        retry_optimistic_lock(skipped, name: 'ci_retry_pipeline') { |build| build.process(current_user) }
       end
 
       pipeline.reset_ancestor_bridges!

app/services/deployments/older_deployments_drop_service.rb

@@ -12,7 +12,7 @@ module Deployments
       return unless @deployment&.running?
 
       older_deployments.find_each do |older_deployment|
-        Gitlab::OptimisticLocking.retry_lock(older_deployment.deployable) do |deployable|
+        Gitlab::OptimisticLocking.retry_lock(older_deployment.deployable, name: 'older_deployments_drop') do |deployable|
           deployable.drop(:forward_deployment_failure)
         end
       rescue => e

app/services/terraform/remote_state_handler.rb

@@ -60,7 +60,7 @@ module Terraform
     private
 
     def retrieve_with_lock(find_only: false)
-      create_or_find!(find_only: find_only).tap { |state| retry_optimistic_lock(state) { |state| yield state } }
+      create_or_find!(find_only: find_only).tap { |state| retry_optimistic_lock(state, name: 'terraform_remote_state_handler_retrieve') { |state| yield state } }
     end
 
     def create_or_find!(find_only:)

app/workers/stuck_ci_jobs_worker.rb

@@ -70,7 +70,7 @@ class StuckCiJobsWorker # rubocop:disable Scalability/IdempotentWorker
 
   def drop_build(type, build, status, timeout, reason)
     Gitlab::AppLogger.info "#{self.class}: Dropping #{type} build #{build.id} for runner #{build.runner_id} (status: #{status}, timeout: #{timeout}, reason: #{reason})"
-    Gitlab::OptimisticLocking.retry_lock(build, 3) do |b|
+    Gitlab::OptimisticLocking.retry_lock(build, 3, name: 'stuck_ci_jobs_worker_drop_build') do |b|
       b.drop(reason)
     end
   rescue => ex

changelogs/unreleased/322125-log-optimistic-locking-retries.yml

+---
+title: Log Optimistic Locks with retries
+merge_request: 55187
+author:
+type: other

ee/lib/ee/gitlab/ci/pipeline/chain/limit/activity.rb

@@ -25,7 +25,7 @@ module EE
               def perform!
                 return unless limit.exceeded?
 
-                retry_optimistic_lock(pipeline) do
+                retry_optimistic_lock(pipeline, name: 'ci_pipeline_chain_limit_activity') do
                   pipeline.drop!(:activity_limit_exceeded)
                   limit.log_error!(project_id: project.id, plan: project.actual_plan_name)
                 end

ee/lib/ee/gitlab/ci/pipeline/chain/limit/job_activity.rb

@@ -25,7 +25,7 @@ module EE
               def perform!
                 return unless limit.exceeded?
 
-                retry_optimistic_lock(pipeline) do
+                retry_optimistic_lock(pipeline, name: 'ci_pipeline_chain_limit_job_activity') do
                   pipeline.drop!(:job_activity_limit_exceeded)
                   limit.log_error!(project_id: project.id, plan: project.actual_plan_name)
                 end

lib/gitlab/ci/pipeline/chain/cancel_pending_pipelines.rb

@@ -10,7 +10,7 @@ module Gitlab
           def perform!
             return unless project.auto_cancel_pending_pipelines?
 
-            Gitlab::OptimisticLocking.retry_lock(auto_cancelable_pipelines) do |cancelables|
+            Gitlab::OptimisticLocking.retry_lock(auto_cancelable_pipelines, name: 'cancel_pending_pipelines') do |cancelables|
               cancelables.find_each do |cancelable|
                 cancelable.auto_cancel_running(pipeline)
               end

lib/gitlab/optimistic_locking.rb

@@ -2,22 +2,49 @@
 
 module Gitlab
   module OptimisticLocking
+    MAX_RETRIES = 100
+
     module_function
 
-    def retry_lock(subject, retries = nil, &block)
-      retries ||= 100
-      # TODO(Observability): We should be recording details of the number of retries and the duration of the total execution here
+    def retry_lock(subject, max_retries = MAX_RETRIES, name:, &block)
+      start_time = Gitlab::Metrics::System.monotonic_time
+      retry_attempts = 0
+
+      begin
         ActiveRecord::Base.transaction do
           yield(subject)
         end
       rescue ActiveRecord::StaleObjectError
-      retries -= 1
-      raise unless retries >= 0
+        raise unless retry_attempts < max_retries
 
         subject.reset
+
+        retry_attempts += 1
         retry
+      ensure
+        elapsed_time = Gitlab::Metrics::System.monotonic_time - start_time
+
+        log_optimistic_lock_retries(
+          name: name,
+          retry_attempts: retry_attempts,
+          elapsed_time: elapsed_time)
+      end
     end
 
     alias_method :retry_optimistic_lock, :retry_lock
+
+    def log_optimistic_lock_retries(name:, retry_attempts:, elapsed_time:)
+      return unless retry_attempts > 0
+
+      retry_lock_logger.info(
+        message: "Optimistic Lock released with retries",
+        name: name,
+        retries: retry_attempts,
+        time_s: elapsed_time)
+    end
+
+    def retry_lock_logger
+      @retry_lock_logger ||= Gitlab::Services::Logger.build
+    end
   end
 end

spec/lib/gitlab/optimistic_locking_spec.rb

@@ -7,35 +7,81 @@ RSpec.describe Gitlab::OptimisticLocking do
   let!(:pipeline2) { Ci::Pipeline.find(pipeline.id) }
 
   describe '#retry_lock' do
-    it 'does not reload object if state changes' do
+    let(:name) { 'optimistic_locking_spec' }
+
+    context 'when state changed successfully without retries' do
+      subject do
+        described_class.retry_lock(pipeline, name: name) do |lock_subject|
+          lock_subject.succeed
+        end
+      end
+
+      it 'does not reload object' do
         expect(pipeline).not_to receive(:reset)
         expect(pipeline).to receive(:succeed).and_call_original
 
-      described_class.retry_lock(pipeline) do |subject|
-        subject.succeed
+        subject
+      end
+
+      it 'does not create log record' do
+        expect(described_class.retry_lock_logger).not_to receive(:info)
+
+        subject
       end
     end
 
-    it 'retries action if exception is raised' do
+    context 'when at least one retry happened, the change succeeded' do
+      subject do
+        described_class.retry_lock(pipeline2, name: 'optimistic_locking_spec') do |lock_subject|
+          lock_subject.drop
+        end
+      end
+
+      it 'completes the action' do
         pipeline.succeed
 
         expect(pipeline2).to receive(:reset).and_call_original
         expect(pipeline2).to receive(:drop).twice.and_call_original
 
-      described_class.retry_lock(pipeline2) do |subject|
-        subject.drop
+        subject
+      end
+
+      it 'creates a single log record' do
+        pipeline.succeed
+
+        expect(described_class.retry_lock_logger)
+          .to receive(:info)
+          .once
+          .with(hash_including(:time_s, name: name, retries: 1))
+
+        subject
+      end
     end
+
+    context 'when MAX_RETRIES attempts exceeded' do
+      subject do
+        described_class.retry_lock(pipeline, max_retries, name: name) do |lock_subject|
+          lock_subject.lock_version = 100
+          lock_subject.drop
+        end
+      end
+
+      let(:max_retries) { 2 }
+
+      it 'raises an exception' do
+        expect(pipeline).to receive(:drop).exactly(max_retries + 1).times.and_call_original
+
+        expect { subject }.to raise_error(ActiveRecord::StaleObjectError)
       end
 
-    it 'raises exception when too many retries' do
-      expect(pipeline).to receive(:drop).twice.and_call_original
+      it 'creates a single log record' do
+        expect(described_class.retry_lock_logger)
+          .to receive(:info)
+          .once
+          .with(hash_including(:time_s, name: name, retries: max_retries))
 
-      expect do
-        described_class.retry_lock(pipeline, 1) do |subject|
-          subject.lock_version = 100
-          subject.drop
+        expect { subject }.to raise_error(ActiveRecord::StaleObjectError)
       end
-      end.to raise_error(ActiveRecord::StaleObjectError)
     end
   end