Remove ci_decompose_belonging_to_parent_group feature flag

Changelog: performance

app/models/ci/build.rb

@@ -763,9 +763,7 @@ def any_runners_online?
     def any_runners_available?
       cache_for_available_runners do
-        ::Gitlab::Database.allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/339937') do
-          project.active_runners.exists?
-        end
+        project.active_runners.exists?
       end
     end

app/models/ci/runner.rb

@@ -141,16 +141,9 @@ class Runner < Ci::ApplicationRecord
       project_groups = ::Group.joins(:projects).where(projects: { id: project_id })
-      if Feature.enabled?(:ci_decompose_belonging_to_parent_group_of_project_query, default_enabled: :yaml)
-        belonging_to_group(project_groups.self_and_ancestors.pluck(:id))
-      else
-        joins(:groups)
-          .where(namespaces: { id: project_groups.self_and_ancestors.as_ids })
-          .allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/336433')
-      end
+      belonging_to_group(project_groups.self_and_ancestors.pluck(:id))
     }
-    # deprecated
     scope :owned_or_instance_wide, -> (project_id) do
       from_union(
         [
@@ -159,7 +152,7 @@ class Runner < Ci::ApplicationRecord
           instance_type
         ],
         remove_duplicates: false
-      ).allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/336433')
+      )
     end
     scope :assignable_for, ->(project) do

app/models/project.rb

@@ -1775,17 +1775,12 @@ def group_runners
   def all_runners
     Ci::Runner.from_union([runners, group_runners, shared_runners])
-      .allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/339937')
   end
   def all_available_runners
     Ci::Runner.from_union([runners, group_runners, available_shared_runners])
-      .allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/339937')
   end
-  # Once issue 339937 is fixed, please search for all mentioned of
-  # https://gitlab.com/gitlab-org/gitlab/-/issues/339937,
-  # and remove the allow_cross_joins_across_databases.
   def active_runners
     strong_memoize(:active_runners) do
       all_available_runners.active
@@ -1793,9 +1788,7 @@ def active_runners
   end
   def any_online_runners?(&block)
-    ::Gitlab::Database.allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/339937') do
-      online_runners_with_tags.any?(&block)
-    end
+    online_runners_with_tags.any?(&block)
   end
   def valid_runners_token?(token)

app/services/ci/update_build_queue_service.rb

@@ -99,17 +99,15 @@ def tick(build)
     private
     def tick_for(build, runners)
-      ::Gitlab::Database.allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/339937') do
-        runners = runners.with_recent_runner_queue
-        runners = runners.with_tags if Feature.enabled?(:ci_preload_runner_tags, default_enabled: :yaml)
-        metrics.observe_active_runners(-> { runners.to_a.size })
-        runners.each do |runner|
-          metrics.increment_runner_tick(runner)
-          runner.pick_build!(build)
-        end
+      runners = runners.with_recent_runner_queue
+      runners = runners.with_tags if Feature.enabled?(:ci_preload_runner_tags, default_enabled: :yaml)
+      metrics.observe_active_runners(-> { runners.to_a.size })
+      runners.each do |runner|
+        metrics.increment_runner_tick(runner)
+        runner.pick_build!(build)
       end
     end

config/feature_flags/development/ci_decompose_belonging_to_parent_group_of_project_query.yml

----
-name: ci_decompose_belonging_to_parent_group_of_project_query
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/76454
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/348560
-milestone: '14.7'
-type: development
-group: group::pipeline execution
-default_enabled: false

spec/models/ci/runner_spec.rb

@@ -239,44 +239,20 @@
     end
   end
-  context 'when ci_decompose_belonging_to_parent_group_of_project_query is enabled' do
-    context 'when use_traversal_ids* are enabled' do
-      it_behaves_like '.belonging_to_parent_group_of_project'
-    end
-
-    context 'when use_traversal_ids* are disabled' do
-      before do
-        stub_feature_flags(
-          use_traversal_ids: false,
-          use_traversal_ids_for_ancestors: false,
-          use_traversal_ids_for_ancestor_scopes: false
-        )
-      end
-
-      it_behaves_like '.belonging_to_parent_group_of_project'
-    end
+  context 'when use_traversal_ids* are enabled' do
+    it_behaves_like '.belonging_to_parent_group_of_project'
   end
-  context 'when ci_decompose_belonging_to_parent_group_of_project_query is disabled' do
+  context 'when use_traversal_ids* are disabled' do
     before do
-      stub_feature_flags(ci_decompose_belonging_to_parent_group_of_project_query: false)
-    end
-
-    context 'when use_traversal_ids* are enabled' do
-      it_behaves_like '.belonging_to_parent_group_of_project'
+      stub_feature_flags(
+        use_traversal_ids: false,
+        use_traversal_ids_for_ancestors: false,
+        use_traversal_ids_for_ancestor_scopes: false
+      )
     end
-    context 'when use_traversal_ids* are disabled' do
-      before do
-        stub_feature_flags(
-          use_traversal_ids: false,
-          use_traversal_ids_for_ancestors: false,
-          use_traversal_ids_for_ancestor_scopes: false
-        )
-      end
-
-      it_behaves_like '.belonging_to_parent_group_of_project'
-    end
+    it_behaves_like '.belonging_to_parent_group_of_project'
   end
   describe '.owned_or_instance_wide' do