Merge branch '346836-avoid-tps-increase' into 'master'

Avoid DB calls in MultiStore empty DB case guard

See merge request gitlab-org/gitlab!77180

config/initializers/active_record_transaction_observer.rb

 # frozen_string_literal: true
 
+return unless Gitlab.com? || Gitlab.dev_or_test_env?
+
 def feature_flags_available?
   # When the DBMS is not available, an exception (e.g. PG::ConnectionBad) is raised
   active_db_connection = ActiveRecord::Base.connection.active? rescue false
@@ -9,8 +11,6 @@ rescue ActiveRecord::NoDatabaseError
   false
 end
 
-return unless Gitlab.com? || Gitlab.dev_or_test_env?
-
 Gitlab::Application.configure do
   if feature_flags_available? && ::Feature.enabled?(:active_record_transactions_tracking, type: :ops, default_enabled: :yaml)
     Gitlab::Database::Transaction::Observer.register!

lib/gitlab/redis/multi_store.rb

@@ -97,19 +97,22 @@ module Gitlab
       end
 
       def use_primary_and_secondary_stores?
-        feature_flags_available? &&
-          Feature.enabled?("use_primary_and_secondary_stores_for_#{instance_name.underscore}", default_enabled: :yaml) &&
-          !same_redis_store?
+        feature_table_exists? && Feature.enabled?("use_primary_and_secondary_stores_for_#{instance_name.underscore}", default_enabled: :yaml) && !same_redis_store?
       end
 
       def use_primary_store_as_default?
-        feature_flags_available? &&
-          Feature.enabled?("use_primary_store_as_default_for_#{instance_name.underscore}", default_enabled: :yaml) &&
-          !same_redis_store?
+        feature_table_exists? && Feature.enabled?("use_primary_store_as_default_for_#{instance_name.underscore}", default_enabled: :yaml) && !same_redis_store?
       end
 
       private
 
+      # @return [Boolean]
+      def feature_table_exists?
+        Feature::FlipperFeature.table_exists?
+      rescue StandardError
+        false
+      end
+
       def default_store
         use_primary_store_as_default? ? primary_store : secondary_store
       end

spec/lib/gitlab/redis/multi_store_spec.rb

@@ -646,6 +646,26 @@ RSpec.describe Gitlab::Redis::MultiStore do
         expect(multi_store.use_primary_and_secondary_stores?).to be false
       end
     end
+
+    context 'with empty DB' do
+      before do
+        allow(Feature::FlipperFeature).to receive(:table_exists?).and_return(false)
+      end
+
+      it 'multi store is disabled' do
+        expect(multi_store.use_primary_and_secondary_stores?).to be false
+      end
+    end
+
+    context 'when FF table guard raises' do
+      before do
+        allow(Feature::FlipperFeature).to receive(:table_exists?).and_raise
+      end
+
+      it 'multi store is disabled' do
+        expect(multi_store.use_primary_and_secondary_stores?).to be false
+      end
+    end
   end
 
   describe '#use_primary_store_as_default?' do
@@ -668,6 +688,26 @@ RSpec.describe Gitlab::Redis::MultiStore do
         expect(multi_store.use_primary_store_as_default?).to be false
       end
     end
+
+    context 'with empty DB' do
+      before do
+        allow(Feature::FlipperFeature).to receive(:table_exists?).and_return(false)
+      end
+
+      it 'multi store is disabled' do
+        expect(multi_store.use_primary_and_secondary_stores?).to be false
+      end
+    end
+
+    context 'when FF table guard raises' do
+      before do
+        allow(Feature::FlipperFeature).to receive(:table_exists?).and_raise
+      end
+
+      it 'multi store is disabled' do
+        expect(multi_store.use_primary_and_secondary_stores?).to be false
+      end
+    end
   end
 
   def create_redis_store(options, extras = {})