Merge branch 'separate-sidekiq-queues' into 'master'

Use separate queues for all Sidekiq workers

## What does this MR do?

This MR updates all workers so that they (mostly) use their own Sidekiq queues. This in turn allows us to monitor queues more accurately and in the future impose queue specific throttles, limits, etc.

This is a critical part we need in 8.13, despite it being so close to release day.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/23370 for more information.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/23370

See merge request !7006

CHANGELOG.md

@@ -7,6 +7,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 ## 8.13.0 (2016-10-22)
 
   - Fix save button on project pipeline settings page. (!6955)
+  - All Sidekiq workers now use their own queue
   - Avoid race condition when asynchronously removing expired artifacts. (!6881)
   - Improve Merge When Build Succeeds triggers and execute on pipeline success. (!6675)
   - Respond with 404 Not Found for non-existent tags (Linus Thiel)

app/workers/admin_email_worker.rb

 class AdminEmailWorker
   include Sidekiq::Worker
-
-  sidekiq_options retry: false # this job auto-repeats via sidekiq-cron
+  include CronjobQueue
 
   def perform
     repository_check_failed_count = Project.where(last_repository_check_failed: true).count

app/workers/build_coverage_worker.rb

 class BuildCoverageWorker
   include Sidekiq::Worker
-  sidekiq_options queue: :default
+  include BuildQueue
 
   def perform(build_id)
     Ci::Build.find_by(id: build_id)

app/workers/build_email_worker.rb

 class BuildEmailWorker
   include Sidekiq::Worker
+  include BuildQueue
 
   def perform(build_id, recipients, push_data)
     recipients.each do |recipient|

app/workers/build_finished_worker.rb

 class BuildFinishedWorker
   include Sidekiq::Worker
+  include BuildQueue
 
   def perform(build_id)
     Ci::Build.find_by(id: build_id).try do |build|

app/workers/build_hooks_worker.rb

 class BuildHooksWorker
   include Sidekiq::Worker
-  sidekiq_options queue: :default
+  include BuildQueue
 
   def perform(build_id)
     Ci::Build.find_by(id: build_id)

app/workers/build_success_worker.rb

 class BuildSuccessWorker
   include Sidekiq::Worker
-  sidekiq_options queue: :default
+  include BuildQueue
 
   def perform(build_id)
     Ci::Build.find_by(id: build_id).try do |build|

app/workers/clear_database_cache_worker.rb

 # This worker clears all cache fields in the database, working in batches.
 class ClearDatabaseCacheWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
   BATCH_SIZE = 1000
 

app/workers/concerns/build_queue.rb

+# Concern for setting Sidekiq settings for the various CI build workers.
+module BuildQueue
+  extend ActiveSupport::Concern
+
+  included do
+    sidekiq_options queue: :build
+  end
+end

app/workers/concerns/cronjob_queue.rb

+# Concern that sets various Sidekiq settings for workers executed using a
+# cronjob.
+module CronjobQueue
+  extend ActiveSupport::Concern
+
+  included do
+    sidekiq_options queue: :cronjob, retry: false
+  end
+end

app/workers/concerns/dedicated_sidekiq_queue.rb

+# Concern that sets the queue of a Sidekiq worker based on the worker's class
+# name/namespace.
+module DedicatedSidekiqQueue
+  extend ActiveSupport::Concern
+
+  included do
+    sidekiq_options queue: name.sub(/Worker\z/, '').underscore.tr('/', '_')
+  end
+end

app/workers/concerns/pipeline_queue.rb

+# Concern for setting Sidekiq settings for the various CI pipeline workers.
+module PipelineQueue
+  extend ActiveSupport::Concern
+
+  included do
+    sidekiq_options queue: :pipeline
+  end
+end

app/workers/concerns/repository_check_queue.rb

+# Concern for setting Sidekiq settings for the various repository check workers.
+module RepositoryCheckQueue
+  extend ActiveSupport::Concern
+
+  included do
+    sidekiq_options queue: :repository_check, retry: false
+  end
+end

app/workers/delete_user_worker.rb

 class DeleteUserWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
   def perform(current_user_id, delete_user_id, options = {})
     delete_user  = User.find(delete_user_id)

app/workers/email_receiver_worker.rb

 class EmailReceiverWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :incoming_email
+  include DedicatedSidekiqQueue
 
   def perform(raw)
     return unless Gitlab::IncomingEmail.enabled?

app/workers/emails_on_push_worker.rb

 class EmailsOnPushWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
-  sidekiq_options queue: :mailers
   attr_reader :email, :skip_premailer
 
   def perform(project_id, recipients, push_data, options = {})

app/workers/expire_build_artifacts_worker.rb

 class ExpireBuildArtifactsWorker
   include Sidekiq::Worker
+  include CronjobQueue
 
   def perform
     Rails.logger.info 'Scheduling removal of build artifacts'

app/workers/expire_build_instance_artifacts_worker.rb

 class ExpireBuildInstanceArtifactsWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
   def perform(build_id)
     build = Ci::Build

app/workers/git_garbage_collect_worker.rb

 class GitGarbageCollectWorker
   include Sidekiq::Worker
   include Gitlab::ShellAdapter
+  include DedicatedSidekiqQueue
 
-  sidekiq_options queue: :gitlab_shell, retry: false
+  sidekiq_options retry: false
 
   def perform(project_id)
     project = Project.find(project_id)

app/workers/gitlab_shell_worker.rb

 class GitlabShellWorker
   include Sidekiq::Worker
   include Gitlab::ShellAdapter
-
-  sidekiq_options queue: :gitlab_shell
+  include DedicatedSidekiqQueue
 
   def perform(action, *arg)
     gitlab_shell.send(action, *arg)

app/workers/group_destroy_worker.rb

 class GroupDestroyWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include DedicatedSidekiqQueue
 
   def perform(group_id, user_id)
     begin

app/workers/import_export_project_cleanup_worker.rb

 class ImportExportProjectCleanupWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include CronjobQueue
 
   def perform
     ImportExportCleanUpService.new.execute

app/workers/irker_worker.rb

@@ -3,6 +3,7 @@ require 'socket'
 
 class IrkerWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
   def perform(project_id, chans, colors, push_data, settings)
     project = Project.find(project_id)

app/workers/merge_worker.rb

 class MergeWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include DedicatedSidekiqQueue
 
   def perform(merge_request_id, current_user_id, params)
     params = params.with_indifferent_access

app/workers/new_note_worker.rb

 class NewNoteWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include DedicatedSidekiqQueue
 
   def perform(note_id, note_params)
     note = Note.find(note_id)

app/workers/pipeline_hooks_worker.rb

 class PipelineHooksWorker
   include Sidekiq::Worker
-  sidekiq_options queue: :default
+  include PipelineQueue
 
   def perform(pipeline_id)
     Ci::Pipeline.find_by(id: pipeline_id)

app/workers/pipeline_metrics_worker.rb

 class PipelineMetricsWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include PipelineQueue
 
   def perform(pipeline_id)
     Ci::Pipeline.find_by(id: pipeline_id).try do |pipeline|

app/workers/pipeline_process_worker.rb

 class PipelineProcessWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include PipelineQueue
 
   def perform(pipeline_id)
     Ci::Pipeline.find_by(id: pipeline_id)

app/workers/pipeline_success_worker.rb

 class PipelineSuccessWorker
   include Sidekiq::Worker
-  sidekiq_options queue: :default
+  include PipelineQueue
 
   def perform(pipeline_id)
     Ci::Pipeline.find_by(id: pipeline_id).try do |pipeline|

app/workers/pipeline_update_worker.rb

 class PipelineUpdateWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include PipelineQueue
 
   def perform(pipeline_id)
     Ci::Pipeline.find_by(id: pipeline_id)

app/workers/post_receive.rb

 class PostReceive
   include Sidekiq::Worker
-
-  sidekiq_options queue: :post_receive
+  include DedicatedSidekiqQueue
 
   def perform(repo_path, identifier, changes)
     if path = Gitlab.config.repositories.storages.find { |p| repo_path.start_with?(p[1].to_s) }

app/workers/project_cache_worker.rb

@@ -5,8 +5,7 @@
 # storage engine as much.
 class ProjectCacheWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include DedicatedSidekiqQueue
 
   LEASE_TIMEOUT = 15.minutes.to_i
 

app/workers/project_destroy_worker.rb

 class ProjectDestroyWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include DedicatedSidekiqQueue
 
   def perform(project_id, user_id, params)
     begin

app/workers/project_export_worker.rb

 class ProjectExportWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
-  sidekiq_options queue: :gitlab_shell, retry: 3
+  sidekiq_options retry: 3
 
   def perform(current_user_id, project_id)
     current_user = User.find(current_user_id)

app/workers/project_service_worker.rb

 class ProjectServiceWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :project_web_hook
+  include DedicatedSidekiqQueue
 
   def perform(hook_id, data)
     data = data.with_indifferent_access

app/workers/project_web_hook_worker.rb

 class ProjectWebHookWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :project_web_hook
+  include DedicatedSidekiqQueue
 
   def perform(hook_id, data, hook_name)
     data = data.with_indifferent_access

app/workers/prune_old_events_worker.rb

 class PruneOldEventsWorker
   include Sidekiq::Worker
+  include CronjobQueue
 
   def perform
     # Contribution calendar shows maximum 12 months of events.

app/workers/remove_expired_group_links_worker.rb

 class RemoveExpiredGroupLinksWorker
   include Sidekiq::Worker
+  include CronjobQueue
 
   def perform
     ProjectGroupLink.expired.destroy_all

app/workers/remove_expired_members_worker.rb

 class RemoveExpiredMembersWorker
   include Sidekiq::Worker
+  include CronjobQueue
 
   def perform
     Member.expired.find_each do |member|

app/workers/repository_archive_cache_worker.rb

 class RepositoryArchiveCacheWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include CronjobQueue
 
   def perform
     RepositoryArchiveCleanUpService.new.execute

app/workers/repository_check/batch_worker.rb

 module RepositoryCheck
   class BatchWorker
     include Sidekiq::Worker
-  
+    include CronjobQueue
+
     RUN_TIME = 3600
-  
-    sidekiq_options retry: false
-  
+
     def perform
       start = Time.now
-  
+
       # This loop will break after a little more than one hour ('a little
       # more' because `git fsck` may take a few minutes), or if it runs out of
       # projects to check. By default sidekiq-cron will start a new
@@ -17,15 +16,15 @@ module RepositoryCheck
       project_ids.each do |project_id|
         break if Time.now - start >= RUN_TIME
         break unless current_settings.repository_checks_enabled
-  
+
         next unless try_obtain_lease(project_id)
-  
+
         SingleRepositoryWorker.new.perform(project_id)
       end
     end
-  
+
     private
-  
+
     # Project.find_each does not support WHERE clauses and
     # Project.find_in_batches does not support ordering. So we just build an
     # array of ID's. This is OK because we do it only once an hour, because
@@ -39,7 +38,7 @@ module RepositoryCheck
         reorder('last_repository_check_at ASC').limit(limit).pluck(:id)
       never_checked_projects + old_check_projects
     end
-  
+
     def try_obtain_lease(id)
       # Use a 24-hour timeout because on servers/projects where 'git fsck' is
       # super slow we definitely do not want to run it twice in parallel.
@@ -48,7 +47,7 @@ module RepositoryCheck
         timeout: 24.hours
       ).try_obtain
     end
-  
+
     def current_settings
       # No caching of the settings! If we cache them and an admin disables
       # this feature, an active RepositoryCheckWorker would keep going for up

app/workers/repository_check/clear_worker.rb

 module RepositoryCheck
   class ClearWorker
     include Sidekiq::Worker
-
-    sidekiq_options retry: false
+    include RepositoryCheckQueue
 
     def perform
       # Do small batched updates because these updates will be slow and locking

app/workers/repository_check/single_repository_worker.rb

 module RepositoryCheck
   class SingleRepositoryWorker
     include Sidekiq::Worker
-
-    sidekiq_options retry: false
+    include RepositoryCheckQueue
 
     def perform(project_id)
       project = Project.find(project_id)

app/workers/repository_fork_worker.rb

 class RepositoryForkWorker
   include Sidekiq::Worker
   include Gitlab::ShellAdapter
-
-  sidekiq_options queue: :gitlab_shell
+  include DedicatedSidekiqQueue
 
   def perform(project_id, forked_from_repository_storage_path, source_path, target_path)
     Gitlab::Metrics.add_event(:fork_repository,

app/workers/repository_import_worker.rb

 class RepositoryImportWorker
   include Sidekiq::Worker
   include Gitlab::ShellAdapter
-
-  sidekiq_options queue: :gitlab_shell
+  include DedicatedSidekiqQueue
 
   attr_accessor :project, :current_user
 

app/workers/requests_profiles_worker.rb

 class RequestsProfilesWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :default
+  include CronjobQueue
 
   def perform
     Gitlab::RequestProfiler.remove_all_profiles

app/workers/stuck_ci_builds_worker.rb

 class StuckCiBuildsWorker
   include Sidekiq::Worker
+  include CronjobQueue
 
   BUILD_STUCK_TIMEOUT = 1.day
 

app/workers/system_hook_worker.rb

 class SystemHookWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :system_hook
+  include DedicatedSidekiqQueue
 
   def perform(hook_id, data, hook_name)
     SystemHook.find(hook_id).execute(data, hook_name)

app/workers/trending_projects_worker.rb

 class TrendingProjectsWorker
   include Sidekiq::Worker
-
-  sidekiq_options queue: :trending_projects
+  include CronjobQueue
 
   def perform
     Rails.logger.info('Refreshing trending projects')

app/workers/update_merge_requests_worker.rb

 class UpdateMergeRequestsWorker
   include Sidekiq::Worker
+  include DedicatedSidekiqQueue
 
   def perform(project_id, user_id, oldrev, newrev, ref)
     project = Project.find_by(id: project_id)

bin/background_jobs

@@ -4,6 +4,7 @@ cd $(dirname $0)/..
 app_root=$(pwd)
 sidekiq_pidfile="$app_root/tmp/pids/sidekiq.pid"
 sidekiq_logfile="$app_root/log/sidekiq.log"
+sidekiq_config="$app_root/config/sidekiq_queues.yml"
 gitlab_user=$(ls -l config.ru | awk '{print $3}')
 
 warn()
@@ -37,7 +38,7 @@ start_no_deamonize()
 
 start_sidekiq()
 {
-  exec bundle exec sidekiq -q post_receive -q mailers -q archive_repo -q system_hook -q project_web_hook -q gitlab_shell -q incoming_email -q runner -q common -q default -e $RAILS_ENV -P $sidekiq_pidfile "$@"
+  exec bundle exec sidekiq -C "${sidekiq_config}" -e $RAILS_ENV -P $sidekiq_pidfile "$@"
 }
 
 load_ok()

config/application.rb

@@ -24,7 +24,8 @@ module Gitlab
                                      #{config.root}/app/models/ci
                                      #{config.root}/app/models/hooks
                                      #{config.root}/app/models/members
-                                     #{config.root}/app/models/project_services))
+                                     #{config.root}/app/models/project_services
+                                     #{config.root}/app/workers/concerns))
 
     config.generators.templates.push("#{config.root}/generator_templates")
 

config/sidekiq_queues.yml

+# 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
+:queues:
+  - [post_receive, 5]
+  - [merge, 5]
+  - [update_merge_requests, 3]
+  - [new_note, 2]
+  - [build, 2]
+  - [pipeline, 2]
+  - [gitlab_shell, 2]
+  - [email_receiver, 2]
+  - [emails_on_push, 2]
+  - [repository_fork, 1]
+  - [repository_import, 1]
+  - [project_service, 1]
+  - [clear_database_cache, 1]
+  - [delete_user, 1]
+  - [expire_build_instance_artifacts, 1]
+  - [group_destroy, 1]
+  - [irker, 1]
+  - [project_cache, 1]
+  - [project_destroy, 1]
+  - [project_export, 1]
+  - [project_web_hook, 1]
+  - [repository_check, 1]
+  - [system_hook, 1]
+  - [git_garbage_collect, 1]
+  - [cronjob, 1]
+  - [default, 1]

db/migrate/20161019190736_migrate_sidekiq_queues_from_default.rb

+require 'json'
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class MigrateSidekiqQueuesFromDefault < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = true
+
+  DOWNTIME_REASON = <<-EOF
+  Moving Sidekiq jobs from queues requires Sidekiq to be stopped. Not stopping
+  Sidekiq will result in the loss of jobs that are scheduled after this
+  migration completes.
+  EOF
+
+  disable_ddl_transaction!
+
+  # Jobs for which the queue names have been changed (e.g. multiple workers
+  # using the same non-default queue).
+  #
+  # The keys are the old queue names, the values the jobs to move and their new
+  # queue names.
+  RENAMED_QUEUES = {
+    gitlab_shell: {
+      'GitGarbageCollectorWorker' => :git_garbage_collector,
+      'ProjectExportWorker'       => :project_export,
+      'RepositoryForkWorker'      => :repository_fork,
+      'RepositoryImportWorker'    => :repository_import
+    },
+    project_web_hook: {
+      'ProjectServiceWorker' => :project_service
+    },
+    incoming_email: {
+      'EmailReceiverWorker' => :email_receiver
+    },
+    mailers: {
+      'EmailsOnPushWorker' => :emails_on_push
+    },
+    default: {
+      'AdminEmailWorker'                        => :cronjob,
+      'BuildCoverageWorker'                     => :build,
+      'BuildEmailWorker'                        => :build,
+      'BuildFinishedWorker'                     => :build,
+      'BuildHooksWorker'                        => :build,
+      'BuildSuccessWorker'                      => :build,
+      'ClearDatabaseCacheWorker'                => :clear_database_cache,
+      'DeleteUserWorker'                        => :delete_user,
+      'ExpireBuildArtifactsWorker'              => :cronjob,
+      'ExpireBuildInstanceArtifactsWorker'      => :expire_build_instance_artifacts,
+      'GroupDestroyWorker'                      => :group_destroy,
+      'ImportExportProjectCleanupWorker'        => :cronjob,
+      'IrkerWorker'                             => :irker,
+      'MergeWorker'                             => :merge,
+      'NewNoteWorker'                           => :new_note,
+      'PipelineHooksWorker'                     => :pipeline,
+      'PipelineMetricsWorker'                   => :pipeline,
+      'PipelineProcessWorker'                   => :pipeline,
+      'PipelineSuccessWorker'                   => :pipeline,
+      'PipelineUpdateWorker'                    => :pipeline,
+      'ProjectCacheWorker'                      => :project_cache,
+      'ProjectDestroyWorker'                    => :project_destroy,
+      'PruneOldEventsWorker'                    => :cronjob,
+      'RemoveExpiredGroupLinksWorker'           => :cronjob,
+      'RemoveExpiredMembersWorker'              => :cronjob,
+      'RepositoryArchiveCacheWorker'            => :cronjob,
+      'RepositoryCheck::BatchWorker'            => :cronjob,
+      'RepositoryCheck::ClearWorker'            => :repository_check,
+      'RepositoryCheck::SingleRepositoryWorker' => :repository_check,
+      'RequestsProfilesWorker'                  => :cronjob,
+      'StuckCiBuildsWorker'                     => :cronjob,
+      'UpdateMergeRequestsWorker'               => :update_merge_requests
+    }
+  }
+
+  def up
+    Sidekiq.redis do |redis|
+      RENAMED_QUEUES.each do |queue, jobs|
+        migrate_from_queue(redis, queue, jobs)
+      end
+    end
+  end
+
+  def down
+    Sidekiq.redis do |redis|
+      RENAMED_QUEUES.each do |dest_queue, jobs|
+        jobs.each do |worker, from_queue|
+          migrate_from_queue(redis, from_queue, worker => dest_queue)
+        end
+      end
+    end
+  end
+
+  def migrate_from_queue(redis, queue, job_mapping)
+    while job = redis.lpop("queue:#{queue}")
+      payload = JSON.load(job)
+      new_queue = job_mapping[payload['class']]
+
+      # If we have no target queue to migrate to we're probably dealing with
+      # some ancient job for which the worker no longer exists. In that case
+      # there's no sane option we can take, other than just dropping the job.
+      next unless new_queue
+
+      payload['queue'] = new_queue
+
+      redis.lpush("queue:#{new_queue}", JSON.dump(payload))
+    end
+  end
+end

doc/development/README.md

@@ -14,7 +14,8 @@
 - [Testing standards and style guidelines](testing.md)
 - [UI guide](ui_guide.md) for building GitLab with existing CSS styles and elements
 - [Frontend guidelines](frontend.md)
-- [SQL guidelines](sql.md) for SQL guidelines
+- [SQL guidelines](sql.md) for working with SQL queries
+- [Sidekiq guidelines](sidekiq_style_guide.md) for working with Sidekiq workers
 
 ## Process
 

doc/development/sidekiq_style_guide.md

+# Sidekiq Style Guide
+
+This document outlines various guidelines that should be followed when adding or
+modifying Sidekiq workers.
+
+## Default Queue
+
+Use of the "default" queue is not allowed. Every worker should use a queue that
+matches the worker's purpose the closest. For example, workers that are to be
+executed periodically should use the "cronjob" queue.
+
+A list of all available queues can be found in `config/sidekiq_queues.yml`.
+
+## Dedicated Queues
+
+Most workers should use their own queue. To ease this process a worker can
+include the `DedicatedSidekiqQueue` concern as follows:
+
+```ruby
+class ProcessSomethingWorker
+  include Sidekiq::Worker
+  include DedicatedSidekiqQueue
+end
+```
+
+This will set the queue name based on the class' name, minus the `Worker`
+suffix. In the above example this would lead to the queue being
+`process_something`.
+
+In some cases multiple workers do use the same queue. For example, the various
+workers for updating CI pipelines all use the `pipeline` queue. Adding workers
+to existing queues should be done with care, as adding more workers can lead to
+slow jobs blocking work (even for different jobs) on the shared queue.
+
+## Tests
+
+Each Sidekiq worker must be tested using RSpec, just like any other class. These
+tests should be placed in `spec/workers`.

spec/workers/concerns/build_queue_spec.rb

+require 'spec_helper'
+
+describe BuildQueue do
+  let(:worker) do
+    Class.new do
+      include Sidekiq::Worker
+      include BuildQueue
+    end
+  end
+
+  it 'sets the queue name of a worker' do
+    expect(worker.sidekiq_options['queue'].to_s).to eq('build')
+  end
+end

spec/workers/concerns/cronjob_queue_spec.rb

+require 'spec_helper'
+
+describe CronjobQueue do
+  let(:worker) do
+    Class.new do
+      include Sidekiq::Worker
+      include CronjobQueue
+    end
+  end
+
+  it 'sets the queue name of a worker' do
+    expect(worker.sidekiq_options['queue'].to_s).to eq('cronjob')
+  end
+
+  it 'disables retrying of failed jobs' do
+    expect(worker.sidekiq_options['retry']).to eq(false)
+  end
+end

spec/workers/concerns/dedicated_sidekiq_queue_spec.rb

+require 'spec_helper'
+
+describe DedicatedSidekiqQueue do
+  let(:worker) do
+    Class.new do
+      def self.name
+        'Foo::Bar::DummyWorker'
+      end
+
+      include Sidekiq::Worker
+      include DedicatedSidekiqQueue
+    end
+  end
+
+  describe 'queue names' do
+    it 'sets the queue name based on the class name' do
+      expect(worker.sidekiq_options['queue']).to eq('foo_bar_dummy')
+    end
+  end
+end

spec/workers/concerns/pipeline_queue_spec.rb

+require 'spec_helper'
+
+describe PipelineQueue do
+  let(:worker) do
+    Class.new do
+      include Sidekiq::Worker
+      include PipelineQueue
+    end
+  end
+
+  it 'sets the queue name of a worker' do
+    expect(worker.sidekiq_options['queue'].to_s).to eq('pipeline')
+  end
+end

spec/workers/concerns/repository_check_queue_spec.rb

+require 'spec_helper'
+
+describe RepositoryCheckQueue do
+  let(:worker) do
+    Class.new do
+      include Sidekiq::Worker
+      include RepositoryCheckQueue
+    end
+  end
+
+  it 'sets the queue name of a worker' do
+    expect(worker.sidekiq_options['queue'].to_s).to eq('repository_check')
+  end
+
+  it 'disables retrying of failed jobs' do
+    expect(worker.sidekiq_options['retry']).to eq(false)
+  end
+end

spec/workers/every_sidekiq_worker_spec.rb

+require 'spec_helper'
+
+describe 'Every Sidekiq worker' do
+  let(:workers) do
+    root = Rails.root.join('app', 'workers')
+    concerns = root.join('concerns').to_s
+
+    workers = Dir[root.join('**', '*.rb')].
+      reject { |path| path.start_with?(concerns) }
+
+    workers.map do |path|
+      ns = Pathname.new(path).relative_path_from(root).to_s.gsub('.rb', '')
+
+      ns.camelize.constantize
+    end
+  end
+
+  it 'does not use the default queue' do
+    workers.each do |worker|
+      expect(worker.sidekiq_options['queue'].to_s).not_to eq('default')
+    end
+  end
+
+  it 'uses the cronjob queue when the worker runs as a cronjob' do
+    cron_workers = Settings.cron_jobs.
+      map { |job_name, options| options['job_class'].constantize }.
+      to_set
+
+    workers.each do |worker|
+      next unless cron_workers.include?(worker)
+
+      expect(worker.sidekiq_options['queue'].to_s).to eq('cronjob')
+    end
+  end
+
+  it 'defines the queue in the Sidekiq configuration file' do
+    config = YAML.load_file(Rails.root.join('config', 'sidekiq_queues.yml').to_s)
+    queue_names = config[:queues].map { |(queue, _)| queue }.to_set
+
+    workers.each do |worker|
+      expect(queue_names).to include(worker.sidekiq_options['queue'].to_s)
+    end
+  end
+end