Merge branch 'revert-a0d3be0c' into 'master'

Revert "Merge branch 'remove_ff_gitaly_backup' into 'master'"

See merge request gitlab-org/gitlab!70224

config/feature_flags/development/gitaly_backup.yml

+---
+name: gitaly_backup
+introduced_by_url: https://gitlab.com/gitlab-org/gitaly/-/merge_requests/3554
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/333034
+milestone: '14.0'
+type: development
+group: group::gitaly
+default_enabled: true

doc/raketasks/backup_restore.md

@@ -1480,8 +1480,16 @@ If this happens, examine the following:
 ### `gitaly-backup` for repository backup and restore **(FREE SELF)**
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/333034) in GitLab 14.2.
+> - [Deployed behind a feature flag](../user/feature_flags.md), enabled by default.
+> - Recommended for production use.
+> - For GitLab self-managed instances, GitLab administrators can opt to [disable it](#disable-or-enable-gitaly-backup).
+
+There can be
+[risks when disabling released features](../administration/feature_flags.md#risks-when-disabling-released-features).
+Refer to this feature's version history for more details.
 
 `gitaly-backup` is used by the backup Rake task to create and restore repository backups from Gitaly.
+`gitaly-backup` replaces the previous backup method that directly calls RPCs on Gitaly from GitLab.
 
 The backup Rake task must be able to find this executable. It can be configured in Omnibus GitLab packages:
 
@@ -1493,3 +1501,22 @@ The backup Rake task must be able to find this executable. It can be configured
 
 1. [Reconfigure GitLab](../administration/restart_gitlab.md#omnibus-gitlab-reconfigure)
    for the changes to take effect
+
+#### Disable or enable `gitaly-backup`
+
+`gitaly-backup` is under development but ready for production use.
+It is deployed behind a feature flag that is **enabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../administration/feature_flags.md)
+can opt to disable it.
+
+To disable it:
+
+```ruby
+Feature.disable(:gitaly_backup)
+```
+
+To enable it:
+
+```ruby
+Feature.enable(:gitaly_backup)
+```

ee/lib/ee/backup/repositories.rb

@@ -7,6 +7,11 @@ module EE
 
       private
 
+      override :repository_storage_klasses
+      def repository_storage_klasses
+        super << GroupWikiRepository
+      end
+
       def group_relation
         ::Group.includes(:route, :owners, group_wiki_repository: :shard) # rubocop: disable CodeReuse/ActiveRecord
       end
@@ -17,6 +22,15 @@ module EE
         end
       end
 
+      override :enqueue_container
+      def enqueue_container(container)
+        if container.is_a?(Group)
+          enqueue_group(container)
+        else
+          super
+        end
+      end
+
       def enqueue_group(group)
         strategy.enqueue(group, ::Gitlab::GlRepository::WIKI)
       end
@@ -33,6 +47,15 @@ module EE
           enqueue_group(group)
         end
       end
+
+      override :records_to_enqueue
+      def records_to_enqueue(storage)
+        super << groups_in_storage(storage)
+      end
+
+      def groups_in_storage(storage)
+        group_relation.id_in(GroupWikiRepository.for_repository_storage(storage).select(:group_id))
+      end
     end
   end
 end

ee/spec/lib/ee/backup/repositories_spec.rb

@@ -9,8 +9,6 @@ RSpec.describe Backup::Repositories do
   subject { described_class.new(progress, strategy: strategy) }
 
   describe '#dump' do
-    let_it_be(:groups) { create_list(:group, 5, :wiki_repo) }
-
     context 'hashed storage' do
       let_it_be(:project) { create(:project, :repository) }
       let_it_be(:group) { create(:group, :wiki_repo) }
@@ -18,7 +16,7 @@ RSpec.describe Backup::Repositories do
       it 'calls enqueue for each repository type', :aggregate_failures do
         create(:wiki_page, container: group)
 
-        subject.dump
+        subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
 
         expect(strategy).to have_received(:start).with(:create)
         expect(strategy).to have_received(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
@@ -27,32 +25,48 @@ RSpec.describe Backup::Repositories do
       end
     end
 
-    context 'command failure' do
+    context 'no concurrency' do
+      let_it_be(:groups) { create_list(:group, 5, :wiki_repo) }
+
+      it 'creates the expected number of threads' do
+        expect(Thread).not_to receive(:new)
+
+        expect(strategy).to receive(:start).with(:create)
+        groups.each do |group|
+          expect(strategy).to receive(:enqueue).with(group, Gitlab::GlRepository::WIKI)
+        end
+        expect(strategy).to receive(:wait)
+
+        subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
+      end
+
+      describe 'command failure' do
         it 'enqueue_group raises an error' do
           allow(strategy).to receive(:enqueue).with(anything, Gitlab::GlRepository::WIKI).and_raise(IOError)
 
-        expect { subject.dump }.to raise_error(IOError)
+          expect { subject.dump(max_concurrency: 1, max_storage_concurrency: 1) }.to raise_error(IOError)
         end
 
         it 'group query raises an error' do
           allow(Group).to receive_message_chain(:includes, :find_each).and_raise(ActiveRecord::StatementTimeout)
 
-        expect { subject.dump }.to raise_error(ActiveRecord::StatementTimeout)
+          expect { subject.dump(max_concurrency: 1, max_storage_concurrency: 1) }.to raise_error(ActiveRecord::StatementTimeout)
         end
       end
 
       it 'avoids N+1 database queries' do
         control_count = ActiveRecord::QueryRecorder.new do
-        subject.dump
+          subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
         end.count
 
         create_list(:group, 2, :wiki_repo)
 
         expect do
-        subject.dump
+          subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
         end.not_to exceed_query_limit(control_count)
       end
     end
+  end
 
   describe '#restore' do
     let_it_be(:project) { create(:project) }

lib/backup/gitaly_backup.rb

@@ -57,6 +57,10 @@ module Backup
       }.merge(Gitlab::GitalyClient.connection_data(repository.storage)).to_json)
     end
 
+    def parallel_enqueue?
+      false
+    end
+
     private
 
     def started?

lib/backup/gitaly_rpc_backup.rb

+# frozen_string_literal: true
+
+module Backup
+  # Backup and restores repositories using the gitaly RPC
+  class GitalyRpcBackup
+    def initialize(progress)
+      @progress = progress
+    end
+
+    def start(type)
+      raise Error, 'already started' if @type
+
+      @type = type
+      case type
+      when :create
+        FileUtils.rm_rf(backup_repos_path)
+        FileUtils.mkdir_p(Gitlab.config.backup.path)
+        FileUtils.mkdir(backup_repos_path, mode: 0700)
+      when :restore
+        # no op
+      else
+        raise Error, "unknown backup type: #{type}"
+      end
+    end
+
+    def wait
+      @type = nil
+    end
+
+    def enqueue(container, repository_type)
+      backup_restore = BackupRestore.new(
+        progress,
+        repository_type.repository_for(container),
+        backup_repos_path
+      )
+
+      case @type
+      when :create
+        backup_restore.backup
+      when :restore
+        backup_restore.restore(always_create: repository_type.project?)
+      else
+        raise Error, 'not started'
+      end
+    end
+
+    def parallel_enqueue?
+      true
+    end
+
+    private
+
+    attr_reader :progress
+
+    def backup_repos_path
+      @backup_repos_path ||= File.join(Gitlab.config.backup.path, 'repositories')
+    end
+
+    class BackupRestore
+      attr_accessor :progress, :repository, :backup_repos_path
+
+      def initialize(progress, repository, backup_repos_path)
+        @progress = progress
+        @repository = repository
+        @backup_repos_path = backup_repos_path
+      end
+
+      def backup
+        progress.puts " * #{display_repo_path} ... "
+
+        if repository.empty?
+          progress.puts " * #{display_repo_path} ... " + "[EMPTY] [SKIPPED]".color(:cyan)
+          return
+        end
+
+        FileUtils.mkdir_p(repository_backup_path)
+
+        repository.bundle_to_disk(path_to_bundle)
+        repository.gitaly_repository_client.backup_custom_hooks(custom_hooks_tar)
+
+        progress.puts " * #{display_repo_path} ... " + "[DONE]".color(:green)
+
+      rescue StandardError => e
+        progress.puts "[Failed] backing up #{display_repo_path}".color(:red)
+        progress.puts "Error #{e}".color(:red)
+      end
+
+      def restore(always_create: false)
+        progress.puts " * #{display_repo_path} ... "
+
+        repository.remove rescue nil
+
+        if File.exist?(path_to_bundle)
+          repository.create_from_bundle(path_to_bundle)
+          restore_custom_hooks
+        elsif always_create
+          repository.create_repository
+        end
+
+        progress.puts " * #{display_repo_path} ... " + "[DONE]".color(:green)
+
+      rescue StandardError => e
+        progress.puts "[Failed] restoring #{display_repo_path}".color(:red)
+        progress.puts "Error #{e}".color(:red)
+      end
+
+      private
+
+      def display_repo_path
+        "#{repository.full_path} (#{repository.disk_path})"
+      end
+
+      def repository_backup_path
+        @repository_backup_path ||= File.join(backup_repos_path, repository.disk_path)
+      end
+
+      def path_to_bundle
+        @path_to_bundle ||= File.join(backup_repos_path, repository.disk_path + '.bundle')
+      end
+
+      def restore_custom_hooks
+        return unless File.exist?(custom_hooks_tar)
+
+        repository.gitaly_repository_client.restore_custom_hooks(custom_hooks_tar)
+      end
+
+      def custom_hooks_tar
+        File.join(repository_backup_path, "custom_hooks.tar")
+      end
+    end
+  end
+end

lib/backup/repositories.rb

@@ -9,10 +9,36 @@ module Backup
       @strategy = strategy
     end
 
-    def dump
+    def dump(max_concurrency:, max_storage_concurrency:)
       strategy.start(:create)
-      enqueue_consecutive
 
+      # gitaly-backup is designed to handle concurrency on its own. So we want
+      # to avoid entering the buggy concurrency code here when gitaly-backup
+      # is enabled.
+      if (max_concurrency <= 1 && max_storage_concurrency <= 1) || !strategy.parallel_enqueue?
+        return enqueue_consecutive
+      end
+
+      check_valid_storages!
+
+      semaphore = Concurrent::Semaphore.new(max_concurrency)
+      errors = Queue.new
+
+      threads = Gitlab.config.repositories.storages.keys.map do |storage|
+        Thread.new do
+          Rails.application.executor.wrap do
+            enqueue_storage(storage, semaphore, max_storage_concurrency: max_storage_concurrency)
+          rescue StandardError => e
+            errors << e
+          end
+        end
+      end
+
+      ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+        threads.each(&:join)
+      end
+
+      raise errors.pop unless errors.empty?
     ensure
       strategy.wait
     end
@@ -32,6 +58,18 @@ module Backup
 
     attr_reader :progress, :strategy
 
+    def check_valid_storages!
+      repository_storage_klasses.each do |klass|
+        if klass.excluding_repository_storage(Gitlab.config.repositories.storages.keys).exists?
+          raise Error, "repositories.storages in gitlab.yml does not include all storages used by #{klass}"
+        end
+      end
+    end
+
+    def repository_storage_klasses
+      [ProjectRepository, SnippetRepository]
+    end
+
     def enqueue_consecutive
       enqueue_consecutive_projects
       enqueue_consecutive_snippets
@@ -47,6 +85,50 @@ module Backup
       Snippet.find_each(batch_size: 1000) { |snippet| enqueue_snippet(snippet) }
     end
 
+    def enqueue_storage(storage, semaphore, max_storage_concurrency:)
+      errors = Queue.new
+      queue = InterlockSizedQueue.new(1)
+
+      threads = Array.new(max_storage_concurrency) do
+        Thread.new do
+          Rails.application.executor.wrap do
+            while container = queue.pop
+              ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+                semaphore.acquire
+              end
+
+              begin
+                enqueue_container(container)
+              rescue StandardError => e
+                errors << e
+                break
+              ensure
+                semaphore.release
+              end
+            end
+          end
+        end
+      end
+
+      enqueue_records_for_storage(storage, queue, errors)
+
+      raise errors.pop unless errors.empty?
+    ensure
+      queue.close
+      ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+        threads.each(&:join)
+      end
+    end
+
+    def enqueue_container(container)
+      case container
+      when Project
+        enqueue_project(container)
+      when Snippet
+        enqueue_snippet(container)
+      end
+    end
+
     def enqueue_project(project)
       strategy.enqueue(project, Gitlab::GlRepository::PROJECT)
       strategy.enqueue(project, Gitlab::GlRepository::WIKI)
@@ -57,10 +139,32 @@ module Backup
       strategy.enqueue(snippet, Gitlab::GlRepository::SNIPPET)
     end
 
+    def enqueue_records_for_storage(storage, queue, errors)
+      records_to_enqueue(storage).each do |relation|
+        relation.find_each(batch_size: 100) do |project|
+          break unless errors.empty?
+
+          queue.push(project)
+        end
+      end
+    end
+
+    def records_to_enqueue(storage)
+      [projects_in_storage(storage), snippets_in_storage(storage)]
+    end
+
+    def projects_in_storage(storage)
+      project_relation.id_in(ProjectRepository.for_repository_storage(storage).select(:project_id))
+    end
+
     def project_relation
       Project.includes(:route, :group, namespace: :owner)
     end
 
+    def snippets_in_storage(storage)
+      Snippet.id_in(SnippetRepository.for_repository_storage(storage).select(:snippet_id))
+    end
+
     def restore_object_pools
       PoolRepository.includes(:source_project).find_each do |pool|
         progress.puts " - Object pool #{pool.disk_path}..."
@@ -95,6 +199,24 @@ module Backup
 
       Snippet.id_in(invalid_snippets).delete_all
     end
+
+    class InterlockSizedQueue < SizedQueue
+      extend ::Gitlab::Utils::Override
+
+      override :pop
+      def pop(*)
+        ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+          super
+        end
+      end
+
+      override :push
+      def push(*)
+        ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
+          super
+        end
+      end
+    end
   end
 end
 

lib/tasks/gitlab/backup.rake

@@ -102,10 +102,19 @@ namespace :gitlab do
       task create: :gitlab_environment do
         puts_time "Dumping repositories ...".color(:blue)
 
+        max_concurrency = ENV.fetch('GITLAB_BACKUP_MAX_CONCURRENCY', 1).to_i
+        max_storage_concurrency = ENV.fetch('GITLAB_BACKUP_MAX_STORAGE_CONCURRENCY', 1).to_i
+
         if ENV["SKIP"] && ENV["SKIP"].include?("repositories")
           puts_time "[SKIPPED]".color(:cyan)
+        elsif max_concurrency < 1 || max_storage_concurrency < 1
+          puts "GITLAB_BACKUP_MAX_CONCURRENCY and GITLAB_BACKUP_MAX_STORAGE_CONCURRENCY must have a value of at least 1".color(:red)
+          exit 1
         else
-          Backup::Repositories.new(progress, strategy: repository_backup_strategy).dump
+          Backup::Repositories.new(progress, strategy: repository_backup_strategy).dump(
+            max_concurrency: max_concurrency,
+            max_storage_concurrency: max_storage_concurrency
+          )
           puts_time "done".color(:green)
         end
       end
@@ -290,9 +299,13 @@ namespace :gitlab do
     end
 
     def repository_backup_strategy
+      if Feature.enabled?(:gitaly_backup, default_enabled: :yaml)
         max_concurrency = ENV['GITLAB_BACKUP_MAX_CONCURRENCY'].presence
         max_storage_concurrency = ENV['GITLAB_BACKUP_MAX_STORAGE_CONCURRENCY'].presence
         Backup::GitalyBackup.new(progress, parallel: max_concurrency, parallel_storage: max_storage_concurrency)
+      else
+        Backup::GitalyRpcBackup.new(progress)
+      end
     end
   end
   # namespace end: backup

spec/lib/backup/gitaly_rpc_backup_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Backup::GitalyRpcBackup do
+  let(:progress) { spy(:stdout) }
+
+  subject { described_class.new(progress) }
+
+  after do
+    # make sure we do not leave behind any backup files
+    FileUtils.rm_rf(File.join(Gitlab.config.backup.path, 'repositories'))
+  end
+
+  context 'unknown' do
+    it 'fails to start unknown' do
+      expect { subject.start(:unknown) }.to raise_error(::Backup::Error, 'unknown backup type: unknown')
+    end
+  end
+
+  context 'create' do
+    RSpec.shared_examples 'creates a repository backup' do
+      it 'creates repository bundles', :aggregate_failures do
+        # Add data to the wiki, design repositories, and snippets, so they will be included in the dump.
+        create(:wiki_page, container: project)
+        create(:design, :with_file, issue: create(:issue, project: project))
+        project_snippet = create(:project_snippet, :repository, project: project)
+        personal_snippet = create(:personal_snippet, :repository, author: project.owner)
+
+        subject.start(:create)
+        subject.enqueue(project, Gitlab::GlRepository::PROJECT)
+        subject.enqueue(project, Gitlab::GlRepository::WIKI)
+        subject.enqueue(project, Gitlab::GlRepository::DESIGN)
+        subject.enqueue(personal_snippet, Gitlab::GlRepository::SNIPPET)
+        subject.enqueue(project_snippet, Gitlab::GlRepository::SNIPPET)
+        subject.wait
+
+        expect(File).to exist(File.join(Gitlab.config.backup.path, 'repositories', project.disk_path + '.bundle'))
+        expect(File).to exist(File.join(Gitlab.config.backup.path, 'repositories', project.disk_path + '.wiki.bundle'))
+        expect(File).to exist(File.join(Gitlab.config.backup.path, 'repositories', project.disk_path + '.design.bundle'))
+        expect(File).to exist(File.join(Gitlab.config.backup.path, 'repositories', personal_snippet.disk_path + '.bundle'))
+        expect(File).to exist(File.join(Gitlab.config.backup.path, 'repositories', project_snippet.disk_path + '.bundle'))
+      end
+
+      context 'failure' do
+        before do
+          allow_next_instance_of(Repository) do |repository|
+            allow(repository).to receive(:bundle_to_disk) { raise 'Fail in tests' }
+          end
+        end
+
+        it 'logs an appropriate message', :aggregate_failures do
+          subject.start(:create)
+          subject.enqueue(project, Gitlab::GlRepository::PROJECT)
+          subject.wait
+
+          expect(progress).to have_received(:puts).with("[Failed] backing up #{project.full_path} (#{project.disk_path})")
+          expect(progress).to have_received(:puts).with("Error Fail in tests")
+        end
+      end
+    end
+
+    context 'hashed storage' do
+      let_it_be(:project) { create(:project, :repository) }
+
+      it_behaves_like 'creates a repository backup'
+    end
+
+    context 'legacy storage' do
+      let_it_be(:project) { create(:project, :repository, :legacy_storage) }
+
+      it_behaves_like 'creates a repository backup'
+    end
+  end
+
+  context 'restore' do
+    let_it_be(:project) { create(:project, :repository) }
+    let_it_be(:personal_snippet) { create(:personal_snippet, author: project.owner) }
+    let_it_be(:project_snippet) { create(:project_snippet, project: project, author: project.owner) }
+
+    def copy_bundle_to_backup_path(bundle_name, destination)
+      FileUtils.mkdir_p(File.join(Gitlab.config.backup.path, 'repositories', File.dirname(destination)))
+      FileUtils.cp(Rails.root.join('spec/fixtures/lib/backup', bundle_name), File.join(Gitlab.config.backup.path, 'repositories', destination))
+    end
+
+    it 'restores from repository bundles', :aggregate_failures do
+      copy_bundle_to_backup_path('project_repo.bundle', project.disk_path + '.bundle')
+      copy_bundle_to_backup_path('wiki_repo.bundle', project.disk_path + '.wiki.bundle')
+      copy_bundle_to_backup_path('design_repo.bundle', project.disk_path + '.design.bundle')
+      copy_bundle_to_backup_path('personal_snippet_repo.bundle', personal_snippet.disk_path + '.bundle')
+      copy_bundle_to_backup_path('project_snippet_repo.bundle', project_snippet.disk_path + '.bundle')
+
+      subject.start(:restore)
+      subject.enqueue(project, Gitlab::GlRepository::PROJECT)
+      subject.enqueue(project, Gitlab::GlRepository::WIKI)
+      subject.enqueue(project, Gitlab::GlRepository::DESIGN)
+      subject.enqueue(personal_snippet, Gitlab::GlRepository::SNIPPET)
+      subject.enqueue(project_snippet, Gitlab::GlRepository::SNIPPET)
+      subject.wait
+
+      collect_commit_shas = -> (repo) { repo.commits('master', limit: 10).map(&:sha) }
+
+      expect(collect_commit_shas.call(project.repository)).to eq(['393a7d860a5a4c3cc736d7eb00604e3472bb95ec'])
+      expect(collect_commit_shas.call(project.wiki.repository)).to eq(['c74b9948d0088d703ee1fafeddd9ed9add2901ea'])
+      expect(collect_commit_shas.call(project.design_repository)).to eq(['c3cd4d7bd73a51a0f22045c3a4c871c435dc959d'])
+      expect(collect_commit_shas.call(personal_snippet.repository)).to eq(['3b3c067a3bc1d1b695b51e2be30c0f8cf698a06e'])
+      expect(collect_commit_shas.call(project_snippet.repository)).to eq(['6e44ba56a4748be361a841e759c20e421a1651a1'])
+    end
+
+    it 'cleans existing repositories', :aggregate_failures do
+      expect_next_instance_of(DesignManagement::Repository) do |repository|
+        expect(repository).to receive(:remove)
+      end
+
+      # 4 times = project repo + wiki repo + project_snippet repo + personal_snippet repo
+      expect(Repository).to receive(:new).exactly(4).times.and_wrap_original do |method, *original_args|
+        full_path, container, kwargs = original_args
+
+        repository = method.call(full_path, container, **kwargs)
+
+        expect(repository).to receive(:remove)
+
+        repository
+      end
+
+      subject.start(:restore)
+      subject.enqueue(project, Gitlab::GlRepository::PROJECT)
+      subject.enqueue(project, Gitlab::GlRepository::WIKI)
+      subject.enqueue(project, Gitlab::GlRepository::DESIGN)
+      subject.enqueue(personal_snippet, Gitlab::GlRepository::SNIPPET)
+      subject.enqueue(project_snippet, Gitlab::GlRepository::SNIPPET)
+      subject.wait
+    end
+
+    context 'failure' do
+      before do
+        allow_next_instance_of(Repository) do |repository|
+          allow(repository).to receive(:create_repository) { raise 'Fail in tests' }
+          allow(repository).to receive(:create_from_bundle) { raise 'Fail in tests' }
+        end
+      end
+
+      it 'logs an appropriate message', :aggregate_failures do
+        subject.start(:restore)
+        subject.enqueue(project, Gitlab::GlRepository::PROJECT)
+        subject.wait
+
+        expect(progress).to have_received(:puts).with("[Failed] restoring #{project.full_path} (#{project.disk_path})")
+        expect(progress).to have_received(:puts).with("Error Fail in tests")
+      end
+    end
+  end
+end

spec/lib/backup/repositories_spec.rb

@@ -4,7 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Backup::Repositories do
   let(:progress) { spy(:stdout) }
-  let(:strategy) { spy(:strategy) }
+  let(:parallel_enqueue) { true }
+  let(:strategy) { spy(:strategy, parallel_enqueue?: parallel_enqueue) }
 
   subject { described_class.new(progress, strategy: strategy) }
 
@@ -16,7 +17,7 @@ RSpec.describe Backup::Repositories do
         project_snippet = create(:project_snippet, :repository, project: project)
         personal_snippet = create(:personal_snippet, :repository, author: project.owner)
 
-        subject.dump
+        subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
 
         expect(strategy).to have_received(:start).with(:create)
         expect(strategy).to have_received(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
@@ -40,32 +41,134 @@ RSpec.describe Backup::Repositories do
       it_behaves_like 'creates repository bundles'
     end
 
-    context 'command failure' do
+    context 'no concurrency' do
+      it 'creates the expected number of threads' do
+        expect(Thread).not_to receive(:new)
+
+        expect(strategy).to receive(:start).with(:create)
+        projects.each do |project|
+          expect(strategy).to receive(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
+        end
+        expect(strategy).to receive(:wait)
+
+        subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
+      end
+
+      describe 'command failure' do
         it 'enqueue_project raises an error' do
           allow(strategy).to receive(:enqueue).with(anything, Gitlab::GlRepository::PROJECT).and_raise(IOError)
 
-        expect { subject.dump }.to raise_error(IOError)
+          expect { subject.dump(max_concurrency: 1, max_storage_concurrency: 1) }.to raise_error(IOError)
         end
 
         it 'project query raises an error' do
           allow(Project).to receive_message_chain(:includes, :find_each).and_raise(ActiveRecord::StatementTimeout)
 
-        expect { subject.dump }.to raise_error(ActiveRecord::StatementTimeout)
+          expect { subject.dump(max_concurrency: 1, max_storage_concurrency: 1) }.to raise_error(ActiveRecord::StatementTimeout)
+        end
+      end
+
+      it 'avoids N+1 database queries' do
+        control_count = ActiveRecord::QueryRecorder.new do
+          subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
+        end.count
+
+        create_list(:project, 2, :repository)
+
+        expect do
+          subject.dump(max_concurrency: 1, max_storage_concurrency: 1)
+        end.not_to exceed_query_limit(control_count)
+      end
+    end
+
+    context 'concurrency with a strategy without parallel enqueueing support' do
+      let(:parallel_enqueue) { false }
+
+      it 'enqueues all projects sequentially' do
+        expect(Thread).not_to receive(:new)
+
+        expect(strategy).to receive(:start).with(:create)
+        projects.each do |project|
+          expect(strategy).to receive(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
+        end
+        expect(strategy).to receive(:wait)
+
+        subject.dump(max_concurrency: 2, max_storage_concurrency: 2)
+      end
+    end
+
+    [4, 10].each do |max_storage_concurrency|
+      context "max_storage_concurrency #{max_storage_concurrency}", quarantine: 'https://gitlab.com/gitlab-org/gitlab/-/issues/241701' do
+        let(:storage_keys) { %w[default test_second_storage] }
+
+        before do
+          allow(Gitlab.config.repositories.storages).to receive(:keys).and_return(storage_keys)
+        end
+
+        it 'creates the expected number of threads' do
+          expect(Thread).to receive(:new)
+            .exactly(storage_keys.length * (max_storage_concurrency + 1)).times
+            .and_call_original
+
+          expect(strategy).to receive(:start).with(:create)
+          projects.each do |project|
+            expect(strategy).to receive(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
+          end
+          expect(strategy).to receive(:wait)
+
+          subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency)
+        end
+
+        it 'creates the expected number of threads with extra max concurrency' do
+          expect(Thread).to receive(:new)
+            .exactly(storage_keys.length * (max_storage_concurrency + 1)).times
+            .and_call_original
+
+          expect(strategy).to receive(:start).with(:create)
+          projects.each do |project|
+            expect(strategy).to receive(:enqueue).with(project, Gitlab::GlRepository::PROJECT)
+          end
+          expect(strategy).to receive(:wait)
+
+          subject.dump(max_concurrency: 3, max_storage_concurrency: max_storage_concurrency)
+        end
+
+        describe 'command failure' do
+          it 'enqueue_project raises an error' do
+            allow(strategy).to receive(:enqueue).and_raise(IOError)
+
+            expect { subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency) }.to raise_error(IOError)
+          end
+
+          it 'project query raises an error' do
+            allow(Project).to receive_message_chain(:for_repository_storage, :includes, :find_each).and_raise(ActiveRecord::StatementTimeout)
+
+            expect { subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency) }.to raise_error(ActiveRecord::StatementTimeout)
+          end
+
+          context 'misconfigured storages' do
+            let(:storage_keys) { %w[test_second_storage] }
+
+            it 'raises an error' do
+              expect { subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency) }.to raise_error(Backup::Error, 'repositories.storages in gitlab.yml is misconfigured')
+            end
           end
         end
 
         it 'avoids N+1 database queries' do
           control_count = ActiveRecord::QueryRecorder.new do
-        subject.dump
+            subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency)
           end.count
 
           create_list(:project, 2, :repository)
 
           expect do
-        subject.dump
+            subject.dump(max_concurrency: 1, max_storage_concurrency: max_storage_concurrency)
           end.not_to exceed_query_limit(control_count)
         end
       end
+    end
+  end
 
   describe '#restore' do
     let_it_be(:project) { create(:project) }

spec/tasks/gitlab/backup_rake_spec.rb

@@ -383,10 +383,30 @@ RSpec.describe 'gitlab:app namespace rake task', :delete do
         create(:project, :repository)
       end
 
+      it 'has defaults' do
+        expect_next_instance_of(::Backup::Repositories) do |instance|
+          expect(instance).to receive(:dump)
+            .with(max_concurrency: 1, max_storage_concurrency: 1)
+            .and_call_original
+        end
+
+        expect { run_rake_task('gitlab:backup:create') }.to output.to_stdout_from_any_process
+      end
+
       it 'passes through concurrency environment variables' do
+        # The way concurrency is handled will change with the `gitaly_backup`
+        # feature flag. For now we need to check that both ways continue to
+        # work. This will be cleaned up in the rollout issue.
+        # See https://gitlab.com/gitlab-org/gitlab/-/issues/333034
+
         stub_env('GITLAB_BACKUP_MAX_CONCURRENCY', 5)
         stub_env('GITLAB_BACKUP_MAX_STORAGE_CONCURRENCY', 2)
 
+        expect_next_instance_of(::Backup::Repositories) do |instance|
+          expect(instance).to receive(:dump)
+            .with(max_concurrency: 5, max_storage_concurrency: 2)
+            .and_call_original
+        end
         expect(::Backup::GitalyBackup).to receive(:new).with(anything, parallel: 5, parallel_storage: 2).and_call_original
 
         expect { run_rake_task('gitlab:backup:create') }.to output.to_stdout_from_any_process