Merge branch 'switch-thread-to-process-memory-cache' into 'master'

Switch ThreadMemoryCache to ProcessMemoryCache

See merge request gitlab-org/gitlab!31135

app/controllers/admin/application_settings_controller.rb

@@ -5,7 +5,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
 
   # NOTE: Use @application_setting in this controller when you need to access
   # application_settings after it has been modified. This is because the
-  # ApplicationSetting model uses Gitlab::ThreadMemoryCache for caching and the
+  # ApplicationSetting model uses Gitlab::ProcessMemoryCache for caching and the
   # cache might be stale immediately after an update.
   # https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/30233
   before_action :set_application_setting, except: :integrations

app/models/application_setting.rb

@@ -421,7 +421,7 @@ class ApplicationSetting < ApplicationRecord
   # can cause a significant amount of load on Redis, let's cache it in
   # memory.
   def self.cache_backend
-    Gitlab::ThreadMemoryCache.cache_backend
+    Gitlab::ProcessMemoryCache.cache_backend
   end
 
   def recaptcha_or_login_protection_enabled

changelogs/unreleased/switch-thread-to-process-memory-cache.yml

+---
+title: Use process-wide cache for application settings and performance bar
+merge_request: 31135
+author:
+type: performance

config/environments/test.rb

 require 'gitlab/testing/request_blocker_middleware'
 require 'gitlab/testing/request_inspector_middleware'
-require 'gitlab/testing/clear_thread_memory_cache_middleware'
+require 'gitlab/testing/clear_process_memory_cache_middleware'
 
 Rails.application.configure do
   # Make sure the middleware is inserted first in middleware chain
   config.middleware.insert_before(ActionDispatch::Static, Gitlab::Testing::RequestBlockerMiddleware)
   config.middleware.insert_before(ActionDispatch::Static, Gitlab::Testing::RequestInspectorMiddleware)
-  config.middleware.insert_before(ActionDispatch::Static, Gitlab::Testing::ClearThreadMemoryCacheMiddleware)
+  config.middleware.insert_before(ActionDispatch::Static, Gitlab::Testing::ClearProcessMemoryCacheMiddleware)
 
   # Settings specified here will take precedence over those in config/application.rb
 

config/initializers/0_thread_cache.rb

-# frozen_string_literal: true
-
-Gitlab::ThreadMemoryCache.cache_backend

ee/lib/gitlab/geo.rb

@@ -87,7 +87,7 @@ module Gitlab
 
     def self.l1_cache
       SafeRequestStore[:geo_l1_cache] ||=
-        Gitlab::JsonCache.new(namespace: :geo, backend: ::Gitlab::ThreadMemoryCache.cache_backend)
+        Gitlab::JsonCache.new(namespace: :geo, backend: ::Gitlab::ProcessMemoryCache.cache_backend)
     end
 
     def self.l2_cache

ee/spec/lib/gitlab/geo_spec.rb

@@ -13,7 +13,7 @@ describe Gitlab::Geo, :geo, :request_store do
     it 'includes GitLab version and Rails.version in the cache key' do
       expanded_key = "geo:#{key}:#{Gitlab::VERSION}:#{Rails.version}"
 
-      expect(Gitlab::ThreadMemoryCache.cache_backend).to receive(:write)
+      expect(Gitlab::ProcessMemoryCache.cache_backend).to receive(:write)
         .with(expanded_key, an_instance_of(String), expires_in: 1.minute).and_call_original
       expect(Rails.cache).to receive(:write)
         .with(expanded_key, an_instance_of(String), expires_in: 2.minutes)

ee/spec/requests/projects/audit_events_spec.rb

@@ -21,6 +21,8 @@ describe 'view audit events' do
     end
 
     it 'avoids N+1 DB queries', :request_store do
+      send_request
+
       control = ActiveRecord::QueryRecorder.new(skip_cached: false) { send_request }
 
       create_list(:project_audit_event, 2, entity_id: project.id)

lib/feature.rb

@@ -134,11 +134,7 @@ class Feature
     end
 
     def l1_cache_backend
-      if Gitlab::Utils.to_boolean(ENV['USE_THREAD_MEMORY_CACHE'])
-        Gitlab::ThreadMemoryCache.cache_backend
-      else
-        Gitlab::ProcessMemoryCache.cache_backend
-      end
+      Gitlab::ProcessMemoryCache.cache_backend
     end
 
     def l2_cache_backend

lib/gitlab/performance_bar.rb

@@ -44,7 +44,7 @@ module Gitlab
     end
 
     def self.l1_cache_backend
-      Gitlab::ThreadMemoryCache.cache_backend
+      Gitlab::ProcessMemoryCache.cache_backend
     end
 
     def self.l2_cache_backend

lib/gitlab/testing/clear_thread_memory_cache_middleware.rb → lib/gitlab/testing/clear_process_memory_cache_middleware.rb

@@ -2,13 +2,13 @@
 
 module Gitlab
   module Testing
-    class ClearThreadMemoryCacheMiddleware
+    class ClearProcessMemoryCacheMiddleware
       def initialize(app)
         @app = app
       end
 
       def call(env)
-        Gitlab::ThreadMemoryCache.cache_backend.clear
+        Gitlab::ProcessMemoryCache.cache_backend.clear
 
         @app.call(env)
       end

lib/gitlab/thread_memory_cache.rb

-# frozen_string_literal: true
-
-module Gitlab
-  class ThreadMemoryCache
-    THREAD_KEY = :thread_memory_cache
-
-    def self.cache_backend
-      # Note ActiveSupport::Cache::MemoryStore is thread-safe.  Since
-      # each backend is local per thread we probably don't need to worry
-      # about synchronizing access, but this is a drop-in replacement
-      # for ActiveSupport::Cache::RedisStore.
-      Thread.current[THREAD_KEY] ||= ActiveSupport::Cache::MemoryStore.new
-    end
-  end
-end

spec/lib/feature_spec.rb

@@ -146,14 +146,6 @@ describe Feature do
       expect(described_class.enabled?(:enabled_feature_flag)).to be_truthy
     end
 
-    context 'with USE_THREAD_MEMORY_CACHE defined' do
-      before do
-        stub_env('USE_THREAD_MEMORY_CACHE', '1')
-      end
-
-      it { expect(described_class.l1_cache_backend).to eq(Gitlab::ThreadMemoryCache.cache_backend) }
-    end
-
     it { expect(described_class.l1_cache_backend).to eq(Gitlab::ProcessMemoryCache.cache_backend) }
     it { expect(described_class.l2_cache_backend).to eq(Rails.cache) }
 

spec/lib/gitlab/performance_bar_spec.rb

@@ -38,7 +38,7 @@ describe Gitlab::PerformanceBar do
     end
   end
 
-  it { expect(described_class.l1_cache_backend).to eq(Gitlab::ThreadMemoryCache.cache_backend) }
+  it { expect(described_class.l1_cache_backend).to eq(Gitlab::ProcessMemoryCache.cache_backend) }
   it { expect(described_class.l2_cache_backend).to eq(Rails.cache) }
 
   describe '.enabled_for_user?' do

spec/models/concerns/cacheable_attributes_spec.rb

@@ -205,11 +205,11 @@ describe CacheableAttributes do
       end
     end
 
-    it 'uses RequestStore in addition to Thread memory cache', :request_store do
+    it 'uses RequestStore in addition to process memory cache', :request_store do
       # Warm up the cache
       create(:application_setting).cache!
 
-      expect(ApplicationSetting.cache_backend).to eq(Gitlab::ThreadMemoryCache.cache_backend)
+      expect(ApplicationSetting.cache_backend).to eq(Gitlab::ProcessMemoryCache.cache_backend)
       expect(ApplicationSetting.cache_backend).to receive(:read).with(ApplicationSetting.cache_key).once.and_call_original
 
       2.times { ApplicationSetting.current }

spec/spec_helper.rb

@@ -209,9 +209,7 @@ RSpec.configure do |config|
     # expect(Gitlab::Git::KeepAround).to receive(:execute).and_call_original
     allow(Gitlab::Git::KeepAround).to receive(:execute)
 
-    [Gitlab::ThreadMemoryCache, Gitlab::ProcessMemoryCache].each do |cache|
-      cache.cache_backend.clear
-    end
+    Gitlab::ProcessMemoryCache.cache_backend.clear
 
     Sidekiq::Worker.clear_all