Remove geo_lfs_registry_ssot_sync feature flag

Improve query performance and fix DB timeouts in certain cases, while
finding LFS objects to sync, especially on PostgreSQL 9.6, by using the
registry tables as the single source of truth, instead of doing
cross-database joins e.g. to exclude registry entries that are not
selected for syncing.

ee/app/models/geo/lfs_object_registry.rb

@@ -14,16 +14,7 @@ class Geo::LfsObjectRegistry < Geo::BaseRegistry
   scope :never, -> { where(success: false, retry_count: nil) }
 
   def self.failed
-    if registry_consistency_worker_enabled?
     where(success: false).where.not(retry_count: nil)
-    else
-      # Would do `super` except it doesn't work with an included scope
-      where(success: false)
-    end
-  end
-
-  def self.registry_consistency_worker_enabled?
-    Feature.enabled?(:geo_lfs_registry_ssot_sync)
   end
 
   def self.finder_class

ee/app/workers/geo/file_download_dispatch_worker/lfs_object_job_finder.rb

@@ -12,13 +12,9 @@ module Geo
       end
 
       def find_unsynced_jobs(batch_size:)
-        if Geo::LfsObjectRegistry.registry_consistency_worker_enabled?
         convert_registry_relation_to_job_args(
           registry_finder.find_never_synced_registries(find_batch_params(batch_size))
         )
-        else
-          super
-        end
       end
     end
   end

ee/app/workers/geo/secondary/registry_consistency_worker.rb

@@ -48,7 +48,12 @@ module Geo
       end
 
       def registry_classes
-        @registry_classes ||= REGISTRY_CLASSES.select(&:registry_consistency_worker_enabled?)
+        @registry_classes ||= REGISTRY_CLASSES.select do |registry_class|
+          # Defaults on. This check gives registry classes the opportunity to
+          # disable this worker, e.g. with a feature flag.
+          !registry_class.respond_to?(:registry_consistency_worker_enabled?) ||
+            registry_class.registry_consistency_worker_enabled?
+        end
       end
     end
   end

ee/changelogs/unreleased/mk-fix-geo-db-timeouts-finding-lfs-on-pg-9.yml

+---
+title: 'Geo: Make the LFS registry the SSOT to optimize query performance'
+merge_request: 27154
+author:
+type: performance

ee/spec/workers/geo/file_download_dispatch_worker_spec.rb

@@ -313,7 +313,6 @@ describe Geo::FileDownloadDispatchWorker, :geo, :geo_fdw, :use_sql_query_cache_f
       stub_lfs_object_storage
     end
 
-    context 'with geo_lfs_registry_ssot_sync feature enabled' do
     context 'with files missing on the primary' do
       let!(:lfs_object_file_missing_on_primary) { create(:lfs_object, :with_file) }
 
@@ -361,79 +360,6 @@ describe Geo::FileDownloadDispatchWorker, :geo, :geo_fdw, :use_sql_query_cache_f
     end
   end
 
-    context 'with geo_lfs_registry_ssot_sync feature disabled' do
-      before do
-        stub_feature_flags(geo_lfs_registry_ssot_sync: false)
-      end
-
-      context 'with files missing on the primary' do
-        let!(:lfs_object_file_missing_on_primary) { create(:lfs_object, :with_file) }
-
-        context 'with lfs_object_registry entries' do
-          before do
-            create(:geo_lfs_object_registry, :never_synced, lfs_object: lfs_object_local_store)
-            create(:geo_lfs_object_registry, :failed, lfs_object: lfs_object_remote_store)
-            Geo::LfsObjectRegistry.create!(lfs_object_id: lfs_object_file_missing_on_primary.id, bytes: 1234, success: true, missing_on_primary: true)
-          end
-
-          it 'enqueues file downloads if there is spare capacity' do
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_local_store.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_file_missing_on_primary.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_remote_store.id)
-
-            subject.perform
-          end
-
-          it 'does not enqueue file downloads if there is no spare capacity' do
-            expect(subject).to receive(:db_retrieve_batch_size).and_return(1).twice
-
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).once
-
-            subject.perform
-          end
-
-          it 'does not enqueue file downloads if they are already scheduled' do
-            scheduled_jobs = [{ type: 'lfs', id: lfs_object_file_missing_on_primary.id, job_id: 'foo' }]
-            expect(subject).to receive(:scheduled_jobs).and_return(scheduled_jobs).at_least(1)
-
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_local_store.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_remote_store.id)
-
-            subject.perform
-          end
-        end
-
-        context 'with no lfs_object_registry entries' do
-          it 'enqueues file downloads if there is spare capacity' do
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_local_store.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_file_missing_on_primary.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_remote_store.id)
-
-            subject.perform
-          end
-
-          it 'does not enqueue file downloads if there is no spare capacity' do
-            expect(subject).to receive(:db_retrieve_batch_size).and_return(1).twice
-
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).once
-
-            subject.perform
-          end
-
-          it 'does not enqueue file downloads if they are already scheduled' do
-            scheduled_jobs = [{ type: 'lfs', id: lfs_object_file_missing_on_primary.id, job_id: 'foo' }]
-            expect(subject).to receive(:scheduled_jobs).and_return(scheduled_jobs).at_least(1)
-
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_local_store.id)
-            expect(Geo::FileDownloadWorker).to receive(:perform_async).with('lfs', lfs_object_remote_store.id)
-
-            subject.perform
-          end
-        end
-      end
-    end
-  end
-
   context 'with job artifacts' do
     context 'with geo_job_artifact_registry_ssot_sync feature enabled' do
       before do
@@ -711,22 +637,6 @@ describe Geo::FileDownloadDispatchWorker, :geo, :geo_fdw, :use_sql_query_cache_f
       allow(::GeoNode).to receive(:current_node).and_return(secondary)
     end
 
-    context 'when geo_lfs_registry_ssot_sync feature is disabled' do
-      before do
-        stub_feature_flags(geo_lfs_registry_ssot_sync: false)
-      end
-
-      it 'does not perform Geo::FileDownloadWorker for LFS object that does not belong to selected namespaces to replicate' do
-        lfs_object_in_synced_group = create(:lfs_objects_project, project: project_in_synced_group)
-        create(:lfs_objects_project, project: unsynced_project)
-
-        expect(Geo::FileDownloadWorker).to receive(:perform_async)
-          .with('lfs', lfs_object_in_synced_group.lfs_object_id).once.and_return(spy)
-
-        subject.perform
-      end
-    end
-
     context 'when geo_job_artifact_registry_ssot_sync feature is disabled' do
       before do
         stub_feature_flags(geo_job_artifact_registry_ssot_sync: false)

ee/spec/workers/geo/secondary/registry_consistency_worker_spec.rb

@@ -91,27 +91,6 @@ describe Geo::Secondary::RegistryConsistencyWorker, :geo, :geo_fdw do
       expect(Geo::UploadRegistry.where(file_id: upload.id).count).to eq(1)
     end
 
-    context 'when geo_lfs_registry_ssot_sync is disabled' do
-      let_it_be(:lfs_object) { create(:lfs_object) }
-
-      before do
-        stub_feature_flags(geo_lfs_registry_ssot_sync: false)
-      end
-
-      it 'returns false' do
-        expect(subject.perform).to be_falsey
-      end
-
-      it 'does not execute RegistryConsistencyService for LFS objects' do
-        allow(Geo::RegistryConsistencyService).to receive(:new).with(Geo::JobArtifactRegistry, batch_size: 1000).and_call_original
-        allow(Geo::RegistryConsistencyService).to receive(:new).with(Geo::UploadRegistry, batch_size: 1000).and_call_original
-
-        expect(Geo::RegistryConsistencyService).not_to receive(:new).with(Geo::LfsObjectRegistry, batch_size: 1000)
-
-        subject.perform
-      end
-    end
-
     context 'when geo_job_artifact_registry_ssot_sync is disabled' do
       let_it_be(:job_artifact) { create(:ci_job_artifact) }