Move Sidekiq worker weights to application code

These weights were defined in a config file. (Which is only used if you
don't use sidekiq-cluster.) By moving them to the application code, we
can auto-generate the config file, and it's harder to miss out adding or
updating this weight.

app/workers/authorized_projects_worker.rb

@@ -6,6 +6,7 @@ class AuthorizedProjectsWorker
 
   feature_category :authentication_and_authorization
   latency_sensitive_worker!
+  weight 2
 
   # This is a workaround for a Ruby 2.3.7 bug. rspec-mocks cannot restore the
   # visibility of prepended modules. See https://github.com/rspec/rspec-mocks/issues/1231

app/workers/chat_notification_worker.rb

@@ -8,6 +8,8 @@ class ChatNotificationWorker
   sidekiq_options retry: false
   feature_category :chatops
   latency_sensitive_worker!
+  weight 2
+
   # TODO: break this into multiple jobs
   # as the `responder` uses external dependencies
   # See https://gitlab.com/gitlab-com/gl-infra/scalability/issues/34

app/workers/concerns/self_monitoring_project_worker.rb

@@ -9,6 +9,7 @@ module SelfMonitoringProjectWorker
     # Other Functionality. Metrics seems to be the closest feature_category for
     # this worker.
     feature_category :metrics
+    weight 2
   end
 
   LEASE_TIMEOUT = 15.minutes.to_i

app/workers/concerns/worker_attributes.rb

@@ -7,6 +7,24 @@ module WorkerAttributes
   # `worker_resource_boundary` attribute
   VALID_RESOURCE_BOUNDARIES = [:memory, :cpu, :unknown].freeze
 
+  NAMESPACE_WEIGHTS = {
+    auto_devops: 2,
+    auto_merge: 3,
+    chaos: 2,
+    deployment: 3,
+    mail_scheduler: 2,
+    notifications: 2,
+    pipeline_cache: 3,
+    pipeline_creation: 4,
+    pipeline_default: 3,
+    pipeline_hooks: 2,
+    pipeline_processing: 5,
+
+    # EE-specific
+    epics: 2,
+    incident_management: 2
+  }.stringify_keys.freeze
+
   class_methods do
     def feature_category(value)
       raise "Invalid category. Use `feature_category_not_owned!` to mark a worker as not owned" if value == :not_owned
@@ -70,6 +88,16 @@ module WorkerAttributes
       worker_attributes[:resource_boundary] || :unknown
     end
 
+    def weight(value)
+      worker_attributes[:weight] = value
+    end
+
+    def get_weight
+      worker_attributes[:weight] ||
+        NAMESPACE_WEIGHTS[queue_namespace] ||
+        1
+    end
+
     protected
 
     # Returns a worker attribute declared on this class or its parent class.

app/workers/create_evidence_worker.rb

@@ -4,6 +4,7 @@ class CreateEvidenceWorker
   include ApplicationWorker
 
   feature_category :release_governance
+  weight 2
 
   def perform(release_id)
     release = Release.find_by_id(release_id)

app/workers/create_gpg_signature_worker.rb

@@ -4,6 +4,7 @@ class CreateGpgSignatureWorker
   include ApplicationWorker
 
   feature_category :source_code_management
+  weight 2
 
   # rubocop: disable CodeReuse/ActiveRecord
   def perform(commit_shas, project_id)

app/workers/email_receiver_worker.rb

@@ -5,6 +5,7 @@ class EmailReceiverWorker
 
   feature_category :issue_tracking
   latency_sensitive_worker!
+  weight 2
 
   def perform(raw)
     return unless Gitlab::IncomingEmail.enabled?

app/workers/emails_on_push_worker.rb

@@ -8,6 +8,7 @@ class EmailsOnPushWorker
   feature_category :source_code_management
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 2
 
   def perform(project_id, recipients, push_data, options = {})
     options.symbolize_keys!

app/workers/gitlab_shell_worker.rb

@@ -6,6 +6,7 @@ class GitlabShellWorker
 
   feature_category :source_code_management
   latency_sensitive_worker!
+  weight 2
 
   def perform(action, *arg)
     Gitlab::GitalyClient::NamespaceService.allow do

app/workers/import_issues_csv_worker.rb

@@ -5,6 +5,7 @@ class ImportIssuesCsvWorker
 
   feature_category :issue_tracking
   worker_resource_boundary :cpu
+  weight 2
 
   sidekiq_retries_exhausted do |job|
     Upload.find(job['args'][2]).destroy

app/workers/invalid_gpg_signature_update_worker.rb

@@ -4,6 +4,7 @@ class InvalidGpgSignatureUpdateWorker
   include ApplicationWorker
 
   feature_category :source_code_management
+  weight 2
 
   # rubocop: disable CodeReuse/ActiveRecord
   def perform(gpg_key_id)

app/workers/merge_worker.rb

@@ -5,6 +5,7 @@ class MergeWorker
 
   feature_category :source_code_management
   latency_sensitive_worker!
+  weight 5
 
   def perform(merge_request_id, current_user_id, params)
     params = params.with_indifferent_access

app/workers/new_issue_worker.rb

@@ -7,6 +7,7 @@ class NewIssueWorker
   feature_category :issue_tracking
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 2
 
   def perform(issue_id, user_id)
     return unless objects_found?(issue_id, user_id)

app/workers/new_merge_request_worker.rb

@@ -7,6 +7,7 @@ class NewMergeRequestWorker
   feature_category :source_code_management
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 2
 
   def perform(merge_request_id, user_id)
     return unless objects_found?(merge_request_id, user_id)

app/workers/new_note_worker.rb

@@ -6,6 +6,7 @@ class NewNoteWorker
   feature_category :issue_tracking
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 2
 
   # Keep extra parameter to preserve backwards compatibility with
   # old `NewNoteWorker` jobs (can remove later)

app/workers/new_release_worker.rb

@@ -5,6 +5,7 @@ class NewReleaseWorker
 
   queue_namespace :notifications
   feature_category :release_orchestration
+  weight 2
 
   def perform(release_id)
     release = Release.preloaded.find_by_id(release_id)

app/workers/post_receive.rb

@@ -6,6 +6,7 @@ class PostReceive
   feature_category :source_code_management
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 5
 
   def perform(gl_repository, identifier, changes, push_options = {})
     project, repo_type = Gitlab::GlRepository.parse(gl_repository)

app/workers/process_commit_worker.rb

@@ -12,6 +12,7 @@ class ProcessCommitWorker
 
   feature_category :source_code_management
   latency_sensitive_worker!
+  weight 3
 
   # project_id - The ID of the project this commit belongs to.
   # user_id - The ID of the user that pushed the commit.

app/workers/rebase_worker.rb

@@ -6,6 +6,7 @@ class RebaseWorker
   include ApplicationWorker
 
   feature_category :source_code_management
+  weight 2
 
   def perform(merge_request_id, current_user_id, skip_ci = false)
     current_user = User.find(current_user_id)

app/workers/remote_mirror_notification_worker.rb

@@ -4,6 +4,7 @@ class RemoteMirrorNotificationWorker
   include ApplicationWorker
 
   feature_category :source_code_management
+  weight 2
 
   def perform(remote_mirror_id)
     remote_mirror = RemoteMirror.find_by_id(remote_mirror_id)

app/workers/update_external_pull_requests_worker.rb

@@ -4,6 +4,7 @@ class UpdateExternalPullRequestsWorker
   include ApplicationWorker
 
   feature_category :source_code_management
+  weight 3
 
   def perform(project_id, user_id, ref)
     project = Project.find_by_id(project_id)

app/workers/update_merge_requests_worker.rb

@@ -6,6 +6,7 @@ class UpdateMergeRequestsWorker
   feature_category :source_code_management
   latency_sensitive_worker!
   worker_resource_boundary :cpu
+  weight 3
 
   LOG_TIME_THRESHOLD = 90 # seconds
 

config/sidekiq_queues.yml

+# This file is generated automatically by
+#   bin/rake gitlab:sidekiq:sidekiq_queues_yml:generate
+#
+# Do not edit it manually!
+#
 # This configuration file should be exclusively used to set queue settings for
 # Sidekiq. Any other setting should be specified using the Sidekiq CLI or the
 # Sidekiq Ruby API (see config/initializers/sidekiq.rb).
----
+#
 # All the queues to process and their weights. Every queue _must_ have a weight
 # defined.
 #
@@ -17,116 +22,217 @@
 # to perform) is:
 #
 #     chance = (queue weight / total weight of all queues) * 100
+---
 :queues:
-  - [post_receive, 5]
-  - [merge, 5]
-  - [update_merge_requests, 3]
-  - [process_commit, 3]
-  - [new_note, 2]
-  - [new_issue, 2]
-  - [notifications, 2]
-  - [new_merge_request, 2]
-  - [pipeline_processing, 5]
-  - [pipeline_creation, 4]
-  - [pipeline_default, 3]
-  - [pipeline_cache, 3]
-  - [deployment, 3]
-  - [auto_merge, 3]
-  - [pipeline_hooks, 2]
-  - [gitlab_shell, 2]
-  - [email_receiver, 2]
-  - [emails_on_push, 2]
-  - [mailers, 2]
-  - [mail_scheduler, 2]
-  - [invalid_gpg_signature_update, 2]
-  - [create_gpg_signature, 2]
-  - [rebase, 2]
-  - [upload_checksum, 1]
-  - [repository_fork, 1]
-  - [repository_import, 1]
-  - [github_importer, 1]
-  - [github_import_advance_stage, 1]
-  - [project_service, 1]
-  - [delete_user, 1]
-  - [todos_destroyer, 1]
-  - [delete_merged_branches, 1]
-  - [authorized_projects, 2]
-  - [expire_build_instance_artifacts, 1]
-  - [group_destroy, 1]
-  - [irker, 1]
-  - [namespaceless_project_destroy, 1]
-  - [project_cache, 1]
-  - [project_destroy, 1]
-  - [project_export, 1]
-  - [web_hook, 1]
-  - [repository_check, 1]
-  - [git_garbage_collect, 1]
-  - [reactive_caching, 1]
-  - [cronjob, 1]
-  - [default, 1]
-  - [pages, 1]
-  - [system_hook_push, 1]
-  - [propagate_service_template, 1]
-  - [background_migration, 1]
-  - [gcp_cluster, 1]
-  - [project_migrate_hashed_storage, 1]
-  - [project_rollback_hashed_storage, 1]
-  - [hashed_storage, 1]
-  - [pages_domain_verification, 1]
-  - [pages_domain_ssl_renewal, 1]
-  - [object_storage_upload, 1]
-  - [object_storage, 1]
-  - [file_hook, 1]
-  - [pipeline_background, 1]
-  - [repository_update_remote_mirror, 1]
-  - [repository_remove_remote, 1]
-  - [create_note_diff_file, 1]
-  - [delete_diff_files, 1]
-  - [detect_repository_languages, 1]
-  - [auto_devops, 2]
-  - [container_repository, 1]
-  - [object_pool, 1]
-  - [repository_cleanup, 1]
-  - [delete_stored_files, 1]
-  - [remote_mirror_notification, 2]
-  - [project_daily_statistics, 1]
-  - [import_issues_csv, 2]
-  - [chat_notification, 2]
-  - [migrate_external_diffs, 1]
-  - [update_project_statistics, 1]
-  - [phabricator_import_import_tasks, 1]
-  - [update_namespace_statistics, 1]
-  - [chaos, 2]
-  - [create_evidence, 2]
-  - [group_export, 1]
-  - [self_monitoring_project_create, 2]
-  - [self_monitoring_project_delete, 2]
-  - [error_tracking_issue_link, 2]
-  - [merge_request_mergeability_check, 5]
-
-  # EE-specific queues
-  - [analytics, 1]
-  - [ldap_group_sync, 2]
-  - [create_github_webhook, 2]
-  - [geo, 1]
-  - [repository_update_mirror, 1]
-  - [repository_push_audit_event, 1]
-  - [new_epic, 2]
-  - [project_import_schedule, 1]
-  - [project_update_repository_storage, 1]
-  - [admin_emails, 1]
-  - [elastic_batch_project_indexer, 1]
-  - [elastic_indexer, 1]
-  - [elastic_full_index, 1]
-  - [elastic_commit_indexer, 1]
-  - [elastic_namespace_indexer, 1]
-  - [elastic_namespace_rollout, 1]
-  - [export_csv, 1]
-  - [incident_management, 2]
-  - [jira_connect, 1]
-  - [update_external_pull_requests, 3]
-  - [refresh_license_compliance_checks, 2]
-  - [design_management_new_version, 1]
-  - [epics, 2]
-  - [personal_access_tokens, 1]
-  - [adjourned_project_deletion, 1]
+- - adjourned_project_deletion
+  - 1
+- - admin_emails
+  - 1
+- - authorized_projects
+  - 2
+- - auto_devops
+  - 2
+- - auto_merge
+  - 3
+- - background_migration
+  - 1
+- - chaos
+  - 2
+- - chat_notification
+  - 2
+- - container_repository
+  - 1
+- - create_evidence
+  - 2
+- - create_github_webhook
+  - 2
+- - create_gpg_signature
+  - 2
+- - create_note_diff_file
+  - 1
+- - cronjob
+  - 1
+- - default
+  - 1
+- - delete_diff_files
+  - 1
+- - delete_merged_branches
+  - 1
+- - delete_stored_files
+  - 1
+- - delete_user
+  - 1
+- - deployment
+  - 3
+- - design_management_new_version
+  - 1
+- - detect_repository_languages
+  - 1
+- - elastic_batch_project_indexer
+  - 1
+- - elastic_commit_indexer
+  - 1
+- - elastic_full_index
+  - 1
+- - elastic_indexer
+  - 1
+- - elastic_namespace_indexer
+  - 1
+- - elastic_namespace_rollout
+  - 1
+- - email_receiver
+  - 2
+- - emails_on_push
+  - 2
+- - epics
+  - 2
+- - error_tracking_issue_link
+  - 1
+- - expire_build_instance_artifacts
+  - 1
+- - export_csv
+  - 1
+- - file_hook
+  - 1
+- - gcp_cluster
+  - 1
+- - geo
+  - 1
+- - git_garbage_collect
+  - 1
+- - github_import_advance_stage
+  - 1
+- - github_importer
+  - 1
+- - gitlab_shell
+  - 2
+- - group_destroy
+  - 1
+- - group_export
+  - 1
+- - hashed_storage
+  - 1
+- - import_issues_csv
+  - 2
+- - incident_management
+  - 2
+- - invalid_gpg_signature_update
+  - 2
+- - irker
+  - 1
+- - jira_connect
+  - 1
+- - ldap_group_sync
+  - 2
+- - mail_scheduler
+  - 2
+- - mailers
+  - 2
+- - merge
+  - 5
+- - merge_request_mergeability_check
+  - 1
+- - migrate_external_diffs
+  - 1
+- - namespaceless_project_destroy
+  - 1
+- - new_epic
+  - 2
+- - new_issue
+  - 2
+- - new_merge_request
+  - 2
+- - new_note
+  - 2
+- - notifications
+  - 2
+- - object_pool
+  - 1
+- - object_storage
+  - 1
+- - pages
+  - 1
+- - pages_domain_ssl_renewal
+  - 1
+- - pages_domain_verification
+  - 1
+- - personal_access_tokens
+  - 1
+- - phabricator_import_import_tasks
+  - 1
+- - pipeline_background
+  - 1
+- - pipeline_cache
+  - 3
+- - pipeline_creation
+  - 4
+- - pipeline_default
+  - 3
+- - pipeline_hooks
+  - 2
+- - pipeline_processing
+  - 5
+- - post_receive
+  - 5
+- - process_commit
+  - 3
+- - project_cache
+  - 1
+- - project_daily_statistics
+  - 1
+- - project_destroy
+  - 1
+- - project_export
+  - 1
+- - project_import_schedule
+  - 1
+- - project_service
+  - 1
+- - project_update_repository_storage
+  - 1
+- - propagate_service_template
+  - 1
+- - reactive_caching
+  - 1
+- - rebase
+  - 2
+- - refresh_license_compliance_checks
+  - 2
+- - remote_mirror_notification
+  - 2
+- - repository_check
+  - 1
+- - repository_cleanup
+  - 1
+- - repository_fork
+  - 1
+- - repository_import
+  - 1
+- - repository_push_audit_event
+  - 1
+- - repository_remove_remote
+  - 1
+- - repository_update_mirror
+  - 1
+- - repository_update_remote_mirror
+  - 1
+- - self_monitoring_project_create
+  - 2
+- - self_monitoring_project_delete
+  - 2
+- - system_hook_push
+  - 1
+- - todos_destroyer
+  - 1
+- - update_external_pull_requests
+  - 3
+- - update_merge_requests
+  - 3
+- - update_namespace_statistics
+  - 1
+- - update_project_statistics
+  - 1
+- - upload_checksum
+  - 1
+- - web_hook
+  - 1

ee/app/workers/create_github_webhook_worker.rb

@@ -7,6 +7,7 @@ class CreateGithubWebhookWorker
   feature_category :integrations
   worker_resource_boundary :cpu
   worker_has_external_dependencies!
+  weight 2
 
   attr_reader :project
 

ee/app/workers/ldap_group_sync_worker.rb

@@ -5,6 +5,7 @@ class LdapGroupSyncWorker
 
   feature_category :authentication_and_authorization
   worker_has_external_dependencies!
+  weight 2
 
   # rubocop: disable CodeReuse/ActiveRecord
   def perform(group_ids, provider = nil)

ee/app/workers/new_epic_worker.rb

@@ -6,6 +6,7 @@ class NewEpicWorker
 
   feature_category :epics
   worker_resource_boundary :cpu
+  weight 2
 
   def perform(epic_id, user_id)
     return unless objects_found?(epic_id, user_id)

ee/app/workers/refresh_license_compliance_checks_worker.rb

@@ -4,6 +4,7 @@ class RefreshLicenseComplianceChecksWorker
   include ApplicationWorker
 
   feature_category :license_compliance
+  weight 2
 
   def perform(project_id)
     project = Project.find(project_id)

lib/gitlab/sidekiq_config.rb

@@ -6,6 +6,7 @@ module Gitlab
   module SidekiqConfig
     FOSS_QUEUE_CONFIG_PATH = 'app/workers/all_queues.yml'
     EE_QUEUE_CONFIG_PATH = 'ee/app/workers/all_queues.yml'
+    SIDEKIQ_QUEUES_PATH = 'config/sidekiq_queues.yml'
 
     QUEUE_CONFIG_PATHS = [
       FOSS_QUEUE_CONFIG_PATH,
@@ -13,11 +14,19 @@ module Gitlab
     ].compact.freeze
 
     # For queues that don't have explicit workers - default and mailers
-    DummyWorker = Struct.new(:queue)
+    DummyWorker = Struct.new(:queue, :weight) do
+      def queue_namespace
+        nil
+      end
+
+      def get_weight
+        weight
+      end
+    end
 
     DEFAULT_WORKERS = [
-      Gitlab::SidekiqConfig::Worker.new(DummyWorker.new('default'), ee: false),
-      Gitlab::SidekiqConfig::Worker.new(DummyWorker.new('mailers'), ee: false)
+      Gitlab::SidekiqConfig::Worker.new(DummyWorker.new('default', 1), ee: false),
+      Gitlab::SidekiqConfig::Worker.new(DummyWorker.new('mailers', 2), ee: false)
     ].freeze
 
     class << self
@@ -30,7 +39,7 @@ module Gitlab
 
       def config_queues
         @config_queues ||= begin
-          config = YAML.load_file(Rails.root.join('config/sidekiq_queues.yml'))
+          config = YAML.load_file(Rails.root.join(SIDEKIQ_QUEUES_PATH))
           config[:queues].map(&:first)
         end
       end
@@ -65,6 +74,28 @@ module Gitlab
         Gitlab.ee? && ee_workers != YAML.safe_load(File.read(EE_QUEUE_CONFIG_PATH))
       end
 
+      def queues_for_sidekiq_queues_yml
+        namespaces_with_equal_weights =
+          workers
+            .group_by(&:queue_namespace)
+            .map(&:last)
+            .select { |workers| workers.map(&:get_weight).uniq.count == 1 }
+            .map(&:first)
+
+        namespaces = namespaces_with_equal_weights.map(&:queue_namespace).to_set
+        remaining_queues = workers.reject { |worker| namespaces.include?(worker.queue_namespace) }
+
+        (namespaces_with_equal_weights.map(&:namespace_and_weight) +
+         remaining_queues.map(&:queue_and_weight)).sort
+      end
+
+      def sidekiq_queues_yml_outdated?
+        # YAML.load is OK here as we control the file contents
+        config_queues = YAML.load(File.read(SIDEKIQ_QUEUES_PATH))[:queues] # rubocop:disable Security/YAMLLoad
+
+        queues_for_sidekiq_queues_yml != config_queues
+      end
+
       private
 
       def find_workers(root, ee:)

lib/gitlab/sidekiq_config/worker.rb

@@ -7,8 +7,9 @@ module Gitlab
 
       attr_reader :klass
       delegate :feature_category_not_owned?, :get_feature_category,
-               :get_worker_resource_boundary, :latency_sensitive_worker?,
-               :queue, :worker_has_external_dependencies?,
+               :get_weight, :get_worker_resource_boundary,
+               :latency_sensitive_worker?, :queue, :queue_namespace,
+               :worker_has_external_dependencies?,
                to: :klass
 
       def initialize(klass, ee:)
@@ -35,7 +36,7 @@ module Gitlab
 
       # Put namespaced queues first
       def to_sort
-        [queue.include?(':') ? 0 : 1, queue]
+        [queue_namespace ? 0 : 1, queue]
       end
 
       # YAML representation
@@ -46,6 +47,14 @@ module Gitlab
       def to_yaml
         queue
       end
+
+      def namespace_and_weight
+        [queue_namespace, get_weight]
+      end
+
+      def queue_and_weight
+        [queue, get_weight]
+      end
     end
   end
 end

lib/tasks/gitlab/sidekiq.rake

@@ -4,8 +4,13 @@ return if Rails.env.production?
 
 namespace :gitlab do
   namespace :sidekiq do
+    def write_yaml(path, banner, object)
+      File.write(path, banner + YAML.dump(object))
+    end
+
     namespace :all_queues_yml do
-      def write_yaml(path, object)
+      desc 'GitLab | Sidekiq | Generate all_queues.yml based on worker definitions'
+      task generate: :environment do
         banner = <<~BANNER
           # This file is generated automatically by
           #   bin/rake gitlab:sidekiq:all_queues_yml:generate
@@ -13,17 +18,12 @@ namespace :gitlab do
           # Do not edit it manually!
         BANNER
 
-        File.write(path, banner + YAML.dump(object))
-      end
-
-      desc 'GitLab | Sidekiq | Generate all_queues.yml based on worker definitions'
-      task generate: :environment do
         foss_workers, ee_workers = Gitlab::SidekiqConfig.workers_for_all_queues_yml
 
-        write_yaml(Gitlab::SidekiqConfig::FOSS_QUEUE_CONFIG_PATH, foss_workers)
+        write_yaml(Gitlab::SidekiqConfig::FOSS_QUEUE_CONFIG_PATH, banner, foss_workers)
 
         if Gitlab.ee?
-          write_yaml(Gitlab::SidekiqConfig::EE_QUEUE_CONFIG_PATH, ee_workers)
+          write_yaml(Gitlab::SidekiqConfig::EE_QUEUE_CONFIG_PATH, banner, ee_workers)
         end
       end
 
@@ -44,5 +44,57 @@ namespace :gitlab do
         end
       end
     end
+
+    namespace :sidekiq_queues_yml do
+      desc 'GitLab | Sidekiq | Generate sidekiq_queues.yml based on worker definitions'
+      task generate: :environment do
+        banner = <<~BANNER
+          # This file is generated automatically by
+          #   bin/rake gitlab:sidekiq:sidekiq_queues_yml:generate
+          #
+          # Do not edit it manually!
+          #
+          # This configuration file should be exclusively used to set queue settings for
+          # Sidekiq. Any other setting should be specified using the Sidekiq CLI or the
+          # Sidekiq Ruby API (see config/initializers/sidekiq.rb).
+          #
+          # All the queues to process and their weights. Every queue _must_ have a weight
+          # defined.
+          #
+          # The available weights are as follows
+          #
+          # 1: low priority
+          # 2: medium priority
+          # 3: high priority
+          # 5: _super_ high priority, this should only be used for _very_ important queues
+          #
+          # As per http://stackoverflow.com/a/21241357/290102 the formula for calculating
+          # the likelihood of a job being popped off a queue (given all queues have work
+          # to perform) is:
+          #
+          #     chance = (queue weight / total weight of all queues) * 100
+        BANNER
+
+        queues_and_weights = Gitlab::SidekiqConfig.queues_for_sidekiq_queues_yml
+
+        write_yaml(Gitlab::SidekiqConfig::SIDEKIQ_QUEUES_PATH, banner, queues: queues_and_weights)
+      end
+
+      desc 'GitLab | Sidekiq | Validate that sidekiq_queues.yml matches worker definitions'
+      task check: :environment do
+        if Gitlab::SidekiqConfig.sidekiq_queues_yml_outdated?
+          raise <<~MSG
+            Changes in worker queues found, please update the metadata by running:
+
+              bin/rake gitlab:sidekiq:sidekiq_queues_yml:generate
+
+            Then commit and push the changes from:
+
+            - #{Gitlab::SidekiqConfig::SIDEKIQ_QUEUES_PATH}
+
+          MSG
+        end
+      end
+    end
   end
 end

lib/tasks/lint.rake

@@ -38,11 +38,13 @@ unless Rails.env.production?
       ]
 
       if Gitlab.ee?
-        # This task will fail on CE installations (e.g. gitlab-org/gitlab-foss)
-        # since it will detect strings in the locale files that do not exist in
-        # the source files. To work around this we will only enable this task on
-        # EE installations.
+        # These tasks will fail on FOSS installations
+        # (e.g. gitlab-org/gitlab-foss) since they test against a single
+        # file that is generated by an EE installation, which can
+        # contain values that a FOSS installation won't find.  To work
+        # around this we will only enable this task on EE installations.
         tasks << 'gettext:updated_check'
+        tasks << 'gitlab:sidekiq:sidekiq_queues_yml:check'
       end
 
       tasks.each do |task|

spec/lib/gitlab/sidekiq_config/worker_spec.rb

@@ -3,8 +3,11 @@
 require 'fast_spec_helper'
 
 describe Gitlab::SidekiqConfig::Worker do
-  def worker_with_queue(queue)
-    described_class.new(double(queue: queue), ee: false)
+  def create_worker(queue:, weight: 0)
+    namespace = queue.include?(':') && queue.split(':').first
+    inner_worker = double(queue: queue, queue_namespace: namespace, get_weight: weight)
+
+    described_class.new(inner_worker, ee: false)
   end
 
   describe '#ee?' do
@@ -34,9 +37,9 @@ describe Gitlab::SidekiqConfig::Worker do
 
   describe 'delegations' do
     [
-      :feature_category_not_owned?, :get_feature_category,
+      :feature_category_not_owned?, :get_feature_category, :get_weight,
       :get_worker_resource_boundary, :latency_sensitive_worker?, :queue,
-      :worker_has_external_dependencies?
+      :queue_namespace, :worker_has_external_dependencies?
     ].each do |meth|
       it "delegates #{meth} to the worker class" do
         worker = double
@@ -50,8 +53,8 @@ describe Gitlab::SidekiqConfig::Worker do
 
   describe 'sorting' do
     it 'sorts queues with a namespace before those without a namespace' do
-      namespaced_worker = worker_with_queue('namespace:queue')
-      plain_worker = worker_with_queue('a_queue')
+      namespaced_worker = create_worker(queue: 'namespace:queue')
+      plain_worker = create_worker(queue: 'a_queue')
 
       expect([plain_worker, namespaced_worker].sort)
         .to eq([namespaced_worker, plain_worker])
@@ -59,12 +62,12 @@ describe Gitlab::SidekiqConfig::Worker do
 
     it 'sorts alphabetically by queue' do
       workers = [
-        worker_with_queue('namespace:a'),
-        worker_with_queue('namespace:b'),
-        worker_with_queue('other_namespace:a'),
-        worker_with_queue('other_namespace:b'),
-        worker_with_queue('a'),
-        worker_with_queue('b')
+        create_worker(queue: 'namespace:a'),
+        create_worker(queue: 'namespace:b'),
+        create_worker(queue: 'other_namespace:a'),
+        create_worker(queue: 'other_namespace:b'),
+        create_worker(queue: 'a'),
+        create_worker(queue: 'b')
       ]
 
       expect(workers.shuffle.sort).to eq(workers)
@@ -73,12 +76,26 @@ describe Gitlab::SidekiqConfig::Worker do
 
   describe 'YAML encoding' do
     it 'encodes the worker in YAML as a string of the queue' do
-      worker_a = worker_with_queue('a')
-      worker_b = worker_with_queue('b')
+      worker_a = create_worker(queue: 'a')
+      worker_b = create_worker(queue: 'b')
 
       expect(YAML.dump(worker_a)).to eq(YAML.dump('a'))
       expect(YAML.dump([worker_a, worker_b]))
         .to eq(YAML.dump(%w[a b]))
     end
   end
+
+  describe '#namespace_and_weight' do
+    it 'returns a namespace, weight pair for the worker' do
+      expect(create_worker(queue: 'namespace:a', weight: 2).namespace_and_weight)
+        .to eq(['namespace', 2])
+    end
+  end
+
+  describe '#queue_and_weight' do
+    it 'returns a queue, weight pair for the worker' do
+      expect(create_worker(queue: 'namespace:a', weight: 2).queue_and_weight)
+        .to eq(['namespace:a', 2])
+    end
+  end
 end

spec/lib/gitlab/sidekiq_config_spec.rb

@@ -80,4 +80,64 @@ describe Gitlab::SidekiqConfig do
       expect(described_class.all_queues_yml_outdated?).to be(false)
     end
   end
+
+  describe '.queues_for_sidekiq_queues_yml' do
+    before do
+      workers = [
+        Namespaces::RootStatisticsWorker,
+        Namespaces::ScheduleAggregationWorker,
+        MergeWorker,
+        ProcessCommitWorker
+      ].map { |worker| described_class::Worker.new(worker, ee: false) }
+
+      allow(described_class).to receive(:workers).and_return(workers)
+    end
+
+    it 'returns queues and weights, aggregating namespaces with the same weight' do
+      expected_queues = [
+        ['merge', 5],
+        ['process_commit', 3],
+        ['update_namespace_statistics', 1]
+      ]
+
+      expect(described_class.queues_for_sidekiq_queues_yml).to eq(expected_queues)
+    end
+  end
+
+  describe '.sidekiq_queues_yml_outdated?' do
+    before do
+      workers = [
+        Namespaces::RootStatisticsWorker,
+        Namespaces::ScheduleAggregationWorker,
+        MergeWorker,
+        ProcessCommitWorker
+      ].map { |worker| described_class::Worker.new(worker, ee: false) }
+
+      allow(described_class).to receive(:workers).and_return(workers)
+    end
+
+    let(:expected_queues) do
+      [
+        ['merge', 5],
+        ['process_commit', 3],
+        ['update_namespace_statistics', 1]
+      ]
+    end
+
+    it 'returns true if the YAML file does not match the application code' do
+      allow(File).to receive(:read)
+                       .with(described_class::SIDEKIQ_QUEUES_PATH)
+                       .and_return(YAML.dump(queues: expected_queues.reverse))
+
+      expect(described_class.sidekiq_queues_yml_outdated?).to be(true)
+    end
+
+    it 'returns false if the YAML file matches the application code' do
+      allow(File).to receive(:read)
+                       .with(described_class::SIDEKIQ_QUEUES_PATH)
+                       .and_return(YAML.dump(queues: expected_queues))
+
+      expect(described_class.sidekiq_queues_yml_outdated?).to be(false)
+    end
+  end
 end