From 9e2964c15a7d387e46e25c83afa478c12a856d77 Mon Sep 17 00:00:00 2001
From: Patricio Cano <suprnova32@gmail.com>
Date: Fri, 4 Nov 2016 12:53:12 -0600
Subject: Allow certain Sidekiq jobs to be throttled

---
 Gemfile                                            |  1 +
 Gemfile.lock                                       |  3 +++
 .../admin/application_settings_controller.rb       |  1 +
 app/models/application_setting.rb                  |  1 +
 .../admin/application_settings/_form.html.haml     | 13 ++++++++++
 config/initializers/sidekiq.rb                     | 16 ++++++++++++
 ...d_sidekiq_throttling_to_application_settings.rb | 29 ++++++++++++++++++++++
 db/schema.rb                                       |  1 +
 lib/gitlab/current_settings.rb                     |  1 +
 9 files changed, 66 insertions(+)
 create mode 100644 db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb

diff --git a/Gemfile b/Gemfile
index cb2a8470126..f2291568d25 100644
--- a/Gemfile
+++ b/Gemfile
@@ -137,6 +137,7 @@ gem 'acts-as-taggable-on', '~> 4.0'
 gem 'sidekiq', '~> 4.2'
 gem 'sidekiq-cron', '~> 0.4.0'
 gem 'redis-namespace', '~> 1.5.2'
+gem 'sidekiq-limit_fetch', '~> 3.4'
 
 # HTTP requests
 gem 'httparty', '~> 0.13.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index 290e4c3e1b3..81b43f2238a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -685,6 +685,8 @@ GEM
       redis-namespace (>= 1.5.2)
       rufus-scheduler (>= 2.0.24)
       sidekiq (>= 4.0.0)
+    sidekiq-limit_fetch (3.4.0)
+      sidekiq (>= 4)
     simplecov (0.12.0)
       docile (~> 1.1.0)
       json (>= 1.8, < 3)
@@ -961,6 +963,7 @@ DEPENDENCIES
   shoulda-matchers (~> 2.8.0)
   sidekiq (~> 4.2)
   sidekiq-cron (~> 0.4.0)
+  sidekiq-limit_fetch (~> 3.4)
   simplecov (= 0.12.0)
   slack-notifier (~> 1.2.0)
   spinach-rails (~> 0.2.1)
diff --git a/app/controllers/admin/application_settings_controller.rb b/app/controllers/admin/application_settings_controller.rb
index 52e0256943a..a9dcf7615c4 100644
--- a/app/controllers/admin/application_settings_controller.rb
+++ b/app/controllers/admin/application_settings_controller.rb
@@ -117,6 +117,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       :send_user_confirmation_email,
       :container_registry_token_expire_delay,
       :enabled_git_access_protocol,
+      :sidekiq_throttling_enabled,
       :housekeeping_enabled,
       :housekeeping_bitmaps_enabled,
       :housekeeping_incremental_repack_period,
diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index bb60cc8736c..b728083e91c 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -180,6 +180,7 @@ class ApplicationSetting < ActiveRecord::Base
       container_registry_token_expire_delay: 5,
       repository_storages: ['default'],
       user_default_external: false,
+      sidekiq_throttling_enabled: false,
       housekeeping_enabled: true,
       housekeeping_bitmaps_enabled: true,
       housekeeping_incremental_repack_period: 10,
diff --git a/app/views/admin/application_settings/_form.html.haml b/app/views/admin/application_settings/_form.html.haml
index 450ec322f2c..01a14accbba 100644
--- a/app/views/admin/application_settings/_form.html.haml
+++ b/app/views/admin/application_settings/_form.html.haml
@@ -283,6 +283,19 @@
           The amount of points to store in a single UDP packet. More points
           results in fewer but larger UDP packets being sent.
 
+  %fieldset
+    %legend Background Jobs
+    %p
+      These settings require a restart to take effect.
+    .form-group
+      .col-sm-offset-2.col-sm-10
+        .checkbox
+          = f.label :sidekiq_throttling_enabled do
+            = f.check_box :sidekiq_throttling_enabled
+            Enable Sidekiq Job Throttling
+          .help-block
+            Limit the amount of resources slow running jobs are assigned.
+
   %fieldset
     %legend Spam and Anti-bot Protection
     .form-group
diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
index 023af2af23c..6e660a8c026 100644
--- a/config/initializers/sidekiq.rb
+++ b/config/initializers/sidekiq.rb
@@ -1,3 +1,6 @@
+require 'gitlab/current_settings'
+include Gitlab::CurrentSettings
+
 # Custom Redis configuration
 redis_config_hash = Gitlab::Redis.params
 redis_config_hash[:namespace] = Gitlab::Redis::SIDEKIQ_NAMESPACE
@@ -29,6 +32,19 @@ Sidekiq.configure_server do |config|
   end
   Sidekiq::Cron::Job.load_from_hash! cron_jobs
 
+  # allow it to fail: it may do so when create_from_defaults is executed before migrations are actually done
+  begin
+    throttling_enabled = current_application_settings.sidekiq_throttling_enabled
+  rescue
+    throttling_enabled = false
+  end
+
+  if throttling_enabled
+    { 'project_cache' => 0.1, 'pipeline' => 0.1 }.each do |queue, ratio|
+      Sidekiq::Queue[queue].limit = (ratio * Sidekiq.options[:concurrency]).ceil
+    end
+  end
+
   # Database pool should be at least `sidekiq_concurrency` + 2
   # For more info, see: https://github.com/mperham/sidekiq/blob/master/4.0-Upgrade.md
   config = ActiveRecord::Base.configurations[Rails.env] ||
diff --git a/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb b/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb
new file mode 100644
index 00000000000..e2839219fb7
--- /dev/null
+++ b/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb
@@ -0,0 +1,29 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddSidekiqThrottlingToApplicationSettings < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  # When a migration requires downtime you **must** uncomment the following
+  # constant and define a short and easy to understand explanation as to why the
+  # migration requires downtime.
+  # DOWNTIME_REASON = ''
+
+  # When using the methods "add_concurrent_index" or "add_column_with_default"
+  # you must disable the use of transactions as these methods can not run in an
+  # existing transaction. When using "add_concurrent_index" make sure that this
+  # method is the _only_ method called in the migration, any other changes
+  # should go in a separate migration. This ensures that upon failure _only_ the
+  # index creation fails and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def change
+    add_column :application_settings, :sidekiq_throttling_enabled, :boolean, default: false
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 62c325a52d7..31d01403508 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -98,6 +98,7 @@ ActiveRecord::Schema.define(version: 20161106185620) do
     t.text "help_page_text_html"
     t.text "shared_runners_text_html"
     t.text "after_sign_up_text_html"
+    t.boolean "sidekiq_throttling_enabled", default: false
     t.boolean "housekeeping_enabled", default: true, null: false
     t.boolean "housekeeping_bitmaps_enabled", default: true, null: false
     t.integer "housekeeping_incremental_repack_period", default: 10, null: false
diff --git a/lib/gitlab/current_settings.rb b/lib/gitlab/current_settings.rb
index ef9160d6437..801c2d5abcd 100644
--- a/lib/gitlab/current_settings.rb
+++ b/lib/gitlab/current_settings.rb
@@ -50,6 +50,7 @@ module Gitlab
         repository_checks_enabled: true,
         container_registry_token_expire_delay: 5,
         user_default_external: false,
+        sidekiq_throttling_enabled: false,
       )
     end
 
-- 
cgit v1.2.1


From b95216aabadb336e4ed8cdc01f69e873f47f10d0 Mon Sep 17 00:00:00 2001
From: Patricio Cano <suprnova32@gmail.com>
Date: Fri, 4 Nov 2016 16:54:24 -0600
Subject: Allow the Sidekiq queues to throttle and the factor by which to
 throttle them to be configurable

---
 app/controllers/admin/application_settings_controller.rb |  4 +++-
 app/helpers/application_settings_helper.rb               |  4 ++++
 app/models/application_setting.rb                        | 10 ++++++++++
 app/views/admin/application_settings/_form.html.haml     | 12 ++++++++++++
 config/initializers/sidekiq.rb                           | 16 ++++------------
 ...444_add_sidekiq_throttling_to_application_settings.rb |  2 ++
 db/schema.rb                                             |  2 ++
 lib/gitlab/current_settings.rb                           |  4 ++++
 8 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/app/controllers/admin/application_settings_controller.rb b/app/controllers/admin/application_settings_controller.rb
index a9dcf7615c4..b81842e319b 100644
--- a/app/controllers/admin/application_settings_controller.rb
+++ b/app/controllers/admin/application_settings_controller.rb
@@ -118,6 +118,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       :container_registry_token_expire_delay,
       :enabled_git_access_protocol,
       :sidekiq_throttling_enabled,
+      :sidekiq_throttling_factor,
       :housekeeping_enabled,
       :housekeeping_bitmaps_enabled,
       :housekeeping_incremental_repack_period,
@@ -126,7 +127,8 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       repository_storages: [],
       restricted_visibility_levels: [],
       import_sources: [],
-      disabled_oauth_sign_in_sources: []
+      disabled_oauth_sign_in_sources: [],
+      sidekiq_throttling_queues: []
     )
   end
 end
diff --git a/app/helpers/application_settings_helper.rb b/app/helpers/application_settings_helper.rb
index 45a567a1eba..be5e0301a43 100644
--- a/app/helpers/application_settings_helper.rb
+++ b/app/helpers/application_settings_helper.rb
@@ -100,4 +100,8 @@ module ApplicationSettingsHelper
 
     options_for_select(options, @application_setting.repository_storages)
   end
+
+  def sidekiq_queue_options_for_select
+    options_for_select(Sidekiq::Queue.all.map(&:name), @application_setting.sidekiq_throttling_queues)
+  end
 end
diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index b728083e91c..075e4f4fc9d 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -19,6 +19,7 @@ class ApplicationSetting < ActiveRecord::Base
   serialize :domain_whitelist, Array
   serialize :domain_blacklist, Array
   serialize :repository_storages
+  serialize :sidekiq_throttling_queues
 
   cache_markdown_field :sign_in_text
   cache_markdown_field :help_page_text
@@ -85,6 +86,15 @@ class ApplicationSetting < ActiveRecord::Base
             presence: { message: 'Domain blacklist cannot be empty if Blacklist is enabled.' },
             if: :domain_blacklist_enabled?
 
+  validates :sidekiq_throttling_factor,
+            numericality: { greater_than: 0, less_than: 1 },
+            presence: { message: 'Throttling factor cannot be empty if Sidekiq Throttling is enabled.' },
+            if: :sidekiq_throttling_enabled?
+
+  validates :sidekiq_throttling_queues,
+            presence: { message: 'Queues to throttle cannot be empty if Sidekiq Throttling is enabled.' },
+            if: :sidekiq_throttling_enabled?
+
   validates :housekeeping_incremental_repack_period,
             presence: true,
             numericality: { only_integer: true, greater_than: 0 }
diff --git a/app/views/admin/application_settings/_form.html.haml b/app/views/admin/application_settings/_form.html.haml
index 01a14accbba..9b1b3f0e16e 100644
--- a/app/views/admin/application_settings/_form.html.haml
+++ b/app/views/admin/application_settings/_form.html.haml
@@ -295,6 +295,18 @@
             Enable Sidekiq Job Throttling
           .help-block
             Limit the amount of resources slow running jobs are assigned.
+    .form-group
+      = f.label :sidekiq_throttling_queues, 'Sidekiq queues to throttle', class: 'control-label col-sm-2'
+      .col-sm-10
+        = f.select :sidekiq_throttling_queues, sidekiq_queue_options_for_select, { include_hidden: false }, multiple: true, class: 'select2 select-wide', data: { field: 'sidekiq_throttling_queues' }
+        .help-block
+          Choose which queues you wish to throttle.
+    .form-group
+      = f.label :sidekiq_throttling_factor, 'Throttling Factor', class: 'control-label col-sm-2'
+      .col-sm-10
+        = f.number_field :sidekiq_throttling_factor, class: 'form-control', min: '0', max: '0.99', step: '0.01'
+        .help-block
+          The factor by which the queues should be throttled. A value between 0.1 and 0.9.
 
   %fieldset
     %legend Spam and Anti-bot Protection
diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
index 6e660a8c026..7cc5e396f98 100644
--- a/config/initializers/sidekiq.rb
+++ b/config/initializers/sidekiq.rb
@@ -1,6 +1,3 @@
-require 'gitlab/current_settings'
-include Gitlab::CurrentSettings
-
 # Custom Redis configuration
 redis_config_hash = Gitlab::Redis.params
 redis_config_hash[:namespace] = Gitlab::Redis::SIDEKIQ_NAMESPACE
@@ -32,16 +29,11 @@ Sidekiq.configure_server do |config|
   end
   Sidekiq::Cron::Job.load_from_hash! cron_jobs
 
-  # allow it to fail: it may do so when create_from_defaults is executed before migrations are actually done
-  begin
-    throttling_enabled = current_application_settings.sidekiq_throttling_enabled
-  rescue
-    throttling_enabled = false
-  end
+  if Gitlab::CurrentSettings.sidekiq_throttling_enabled?
+    factor = current_application_settings.sidekiq_throttling_factor
 
-  if throttling_enabled
-    { 'project_cache' => 0.1, 'pipeline' => 0.1 }.each do |queue, ratio|
-      Sidekiq::Queue[queue].limit = (ratio * Sidekiq.options[:concurrency]).ceil
+    current_application_settings.sidekiq_throttling_queues.each do |queue|
+      Sidekiq::Queue[queue].limit = (factor * Sidekiq.options[:concurrency]).ceil
     end
   end
 
diff --git a/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb b/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb
index e2839219fb7..e644a174964 100644
--- a/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb
+++ b/db/migrate/20161103191444_add_sidekiq_throttling_to_application_settings.rb
@@ -25,5 +25,7 @@ class AddSidekiqThrottlingToApplicationSettings < ActiveRecord::Migration
 
   def change
     add_column :application_settings, :sidekiq_throttling_enabled, :boolean, default: false
+    add_column :application_settings, :sidekiq_throttling_queues, :string
+    add_column :application_settings, :sidekiq_throttling_factor, :decimal
   end
 end
diff --git a/db/schema.rb b/db/schema.rb
index 31d01403508..666b54690c1 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -99,6 +99,8 @@ ActiveRecord::Schema.define(version: 20161106185620) do
     t.text "shared_runners_text_html"
     t.text "after_sign_up_text_html"
     t.boolean "sidekiq_throttling_enabled", default: false
+    t.string "sidekiq_throttling_queues"
+    t.decimal "sidekiq_throttling_factor"
     t.boolean "housekeeping_enabled", default: true, null: false
     t.boolean "housekeeping_bitmaps_enabled", default: true, null: false
     t.integer "housekeeping_incremental_repack_period", default: 10, null: false
diff --git a/lib/gitlab/current_settings.rb b/lib/gitlab/current_settings.rb
index 801c2d5abcd..3a651ef318a 100644
--- a/lib/gitlab/current_settings.rb
+++ b/lib/gitlab/current_settings.rb
@@ -23,6 +23,10 @@ module Gitlab
       settings || fake_application_settings
     end
 
+    def sidekiq_throttling_enabled?
+      current_application_settings.sidekiq_throttling_enabled
+    end
+
     def fake_application_settings
       OpenStruct.new(
         default_projects_limit: Settings.gitlab['default_projects_limit'],
-- 
cgit v1.2.1


From 1d3ada80ad6cb9a4927512fdf4018907bf3098a6 Mon Sep 17 00:00:00 2001
From: Patricio Cano <suprnova32@gmail.com>
Date: Mon, 7 Nov 2016 15:44:55 -0600
Subject: Added documentation and CHANGELOG item.

---
 changelogs/unreleased/sidekiq-job-throttling.yml   |   4 +++
 doc/administration/operations.md                   |   1 +
 .../operations/img/sidekiq_job_throttling.png      | Bin 0 -> 114784 bytes
 .../operations/sidekiq_job_throttling.md           |  32 +++++++++++++++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 changelogs/unreleased/sidekiq-job-throttling.yml
 create mode 100644 doc/administration/operations/img/sidekiq_job_throttling.png
 create mode 100644 doc/administration/operations/sidekiq_job_throttling.md

diff --git a/changelogs/unreleased/sidekiq-job-throttling.yml b/changelogs/unreleased/sidekiq-job-throttling.yml
new file mode 100644
index 00000000000..1f3aad7ae96
--- /dev/null
+++ b/changelogs/unreleased/sidekiq-job-throttling.yml
@@ -0,0 +1,4 @@
+---
+title: Added ability to throttle Sidekiq Jobs
+merge_request: 7292
+author: Patricio Cano
diff --git a/doc/administration/operations.md b/doc/administration/operations.md
index 4b582d16b64..0daceb98d99 100644
--- a/doc/administration/operations.md
+++ b/doc/administration/operations.md
@@ -1,6 +1,7 @@
 # GitLab operations
 
 - [Sidekiq MemoryKiller](operations/sidekiq_memory_killer.md)
+- [Sidekiq Job throttling](operations/sidekiq_job_throttling.md)
 - [Cleaning up Redis sessions](operations/cleaning_up_redis_sessions.md)
 - [Understanding Unicorn and unicorn-worker-killer](operations/unicorn.md)
 - [Moving repositories to a new location](operations/moving_repositories.md)
diff --git a/doc/administration/operations/img/sidekiq_job_throttling.png b/doc/administration/operations/img/sidekiq_job_throttling.png
new file mode 100644
index 00000000000..7f29a4d3c46
Binary files /dev/null and b/doc/administration/operations/img/sidekiq_job_throttling.png differ
diff --git a/doc/administration/operations/sidekiq_job_throttling.md b/doc/administration/operations/sidekiq_job_throttling.md
new file mode 100644
index 00000000000..33cedee7ebd
--- /dev/null
+++ b/doc/administration/operations/sidekiq_job_throttling.md
@@ -0,0 +1,32 @@
+# Sidekiq Job throttling
+
+> Note: Introduced with GitLab 8.14
+
+When your GitLab installation needs to handle tens of thousands of background
+jobs, it can be convenient to prioritize queues that need to be executed
+immediately, e.g. user initiated actions like merging a Merge Request.
+
+In order to accomplish this, you can limit the amount of workers that certain
+slow running queues get can have available. This is what we call Sidekiq Job
+Throttling. Depending on your infrastructure, you might have different slow
+running queues, which is why you can choose which queues to throttle and by
+how much you want to throttle them.
+
+These settings are available in the Application Settings of your GitLab
+installation.
+
+![Sidekiq Job Throttling](img/sidekiq_job_throttling.png)
+
+The throttle factor determines the maximum number of workers a queue can run on.
+This value gets multiplied by `:concurrency` value set in the Sidekiq settings
+and rounded up to the closest full integer.
+
+So, for example, you set the `:concurrency` to 25 and the `Throttling factor` to
+0.1, the maximum workers assigned to the selected queues would be 3.
+
+```
+limit = (factor * Sidekiq.options[:concurrency]).ceil
+```
+
+After enabling the job throttling, you will need to restart your GitLab
+instance, in order for the changes to take effect.
\ No newline at end of file
-- 
cgit v1.2.1


From 208530494e5d2c5c62a3e1c24489aae0e4935e3a Mon Sep 17 00:00:00 2001
From: Patricio Cano <suprnova32@gmail.com>
Date: Tue, 8 Nov 2016 16:31:37 -0600
Subject: Refactored initializer code to its own class and added tests

---
 config/initializers/sidekiq.rb            |  8 +-------
 lib/gitlab/sidekiq_throttler.rb           | 21 +++++++++++++++++++
 spec/lib/gitlab/sidekiq_throttler_spec.rb | 34 +++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 7 deletions(-)
 create mode 100644 lib/gitlab/sidekiq_throttler.rb
 create mode 100644 spec/lib/gitlab/sidekiq_throttler_spec.rb

diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
index 7cc5e396f98..b87b31d9697 100644
--- a/config/initializers/sidekiq.rb
+++ b/config/initializers/sidekiq.rb
@@ -29,13 +29,7 @@ Sidekiq.configure_server do |config|
   end
   Sidekiq::Cron::Job.load_from_hash! cron_jobs
 
-  if Gitlab::CurrentSettings.sidekiq_throttling_enabled?
-    factor = current_application_settings.sidekiq_throttling_factor
-
-    current_application_settings.sidekiq_throttling_queues.each do |queue|
-      Sidekiq::Queue[queue].limit = (factor * Sidekiq.options[:concurrency]).ceil
-    end
-  end
+  Gitlab::SidekiqThrottler.execute!
 
   # Database pool should be at least `sidekiq_concurrency` + 2
   # For more info, see: https://github.com/mperham/sidekiq/blob/master/4.0-Upgrade.md
diff --git a/lib/gitlab/sidekiq_throttler.rb b/lib/gitlab/sidekiq_throttler.rb
new file mode 100644
index 00000000000..771736e7606
--- /dev/null
+++ b/lib/gitlab/sidekiq_throttler.rb
@@ -0,0 +1,21 @@
+module Gitlab
+  class SidekiqThrottler
+    class << self
+      def execute!
+        if Gitlab::CurrentSettings.sidekiq_throttling_enabled?
+          current_application_settings.sidekiq_throttling_queues.each do |queue|
+            Sidekiq::Queue[queue].limit = set_limit
+          end
+        end
+      end
+
+      private
+
+      def set_limit
+        factor = current_application_settings.sidekiq_throttling_factor
+
+        (factor * Sidekiq.options[:concurrency]).ceil
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/sidekiq_throttler_spec.rb b/spec/lib/gitlab/sidekiq_throttler_spec.rb
new file mode 100644
index 00000000000..ac4a64c0f43
--- /dev/null
+++ b/spec/lib/gitlab/sidekiq_throttler_spec.rb
@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+describe Gitlab::SidekiqThrottler do
+  before do
+    Sidekiq.options[:concurrency] = 35
+
+    stub_application_setting(
+      sidekiq_throttling_enabled: true,
+      sidekiq_throttling_factor: 0.1,
+      sidekiq_throttling_queues: %w[build project_cache]
+    )
+  end
+
+  describe '#set_limit' do
+    it 'returns the correct limit' do
+      expect(Gitlab::SidekiqThrottler.send(:set_limit)).to eq 4
+    end
+  end
+
+  describe '#execute!' do
+    it 'sets limits on the selected queues' do
+      Gitlab::SidekiqThrottler.execute!
+
+      expect(Sidekiq::Queue['build'].limit).to eq 4
+      expect(Sidekiq::Queue['project_cache'].limit).to eq 4
+    end
+
+    it 'does not set limits on other queues' do
+      Gitlab::SidekiqThrottler.execute!
+
+      expect(Sidekiq::Queue['merge'].limit).to be_nil
+    end
+  end
+end
-- 
cgit v1.2.1


From e840749b84ceb226e46ebdfb489c735e3370cff7 Mon Sep 17 00:00:00 2001
From: Patricio Cano <suprnova32@gmail.com>
Date: Thu, 10 Nov 2016 11:36:52 -0600
Subject: Refactored Sidekiq Throttler and updated documentation

---
 app/models/application_setting.rb                       |  2 +-
 app/views/admin/application_settings/_form.html.haml    |  4 ++--
 changelogs/unreleased/sidekiq-job-throttling.yml        |  2 +-
 doc/administration/operations/sidekiq_job_throttling.md | 15 ++++++++-------
 lib/gitlab/sidekiq_throttler.rb                         | 14 ++++++++------
 spec/lib/gitlab/sidekiq_throttler_spec.rb               |  6 ------
 6 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/app/models/application_setting.rb b/app/models/application_setting.rb
index 075e4f4fc9d..d1e1b45ab43 100644
--- a/app/models/application_setting.rb
+++ b/app/models/application_setting.rb
@@ -19,7 +19,7 @@ class ApplicationSetting < ActiveRecord::Base
   serialize :domain_whitelist, Array
   serialize :domain_blacklist, Array
   serialize :repository_storages
-  serialize :sidekiq_throttling_queues
+  serialize :sidekiq_throttling_queues, Array
 
   cache_markdown_field :sign_in_text
   cache_markdown_field :help_page_text
diff --git a/app/views/admin/application_settings/_form.html.haml b/app/views/admin/application_settings/_form.html.haml
index 9b1b3f0e16e..a236335131a 100644
--- a/app/views/admin/application_settings/_form.html.haml
+++ b/app/views/admin/application_settings/_form.html.haml
@@ -304,9 +304,9 @@
     .form-group
       = f.label :sidekiq_throttling_factor, 'Throttling Factor', class: 'control-label col-sm-2'
       .col-sm-10
-        = f.number_field :sidekiq_throttling_factor, class: 'form-control', min: '0', max: '0.99', step: '0.01'
+        = f.number_field :sidekiq_throttling_factor, class: 'form-control', min: '0.01', max: '0.99', step: '0.01'
         .help-block
-          The factor by which the queues should be throttled. A value between 0.1 and 0.9.
+          The factor by which the queues should be throttled. A value between 0.0 and 1.0, exclusive.
 
   %fieldset
     %legend Spam and Anti-bot Protection
diff --git a/changelogs/unreleased/sidekiq-job-throttling.yml b/changelogs/unreleased/sidekiq-job-throttling.yml
index 1f3aad7ae96..ec4e2051c7e 100644
--- a/changelogs/unreleased/sidekiq-job-throttling.yml
+++ b/changelogs/unreleased/sidekiq-job-throttling.yml
@@ -1,4 +1,4 @@
 ---
 title: Added ability to throttle Sidekiq Jobs
 merge_request: 7292
-author: Patricio Cano
+author:
diff --git a/doc/administration/operations/sidekiq_job_throttling.md b/doc/administration/operations/sidekiq_job_throttling.md
index 33cedee7ebd..ddeaa22e288 100644
--- a/doc/administration/operations/sidekiq_job_throttling.md
+++ b/doc/administration/operations/sidekiq_job_throttling.md
@@ -3,14 +3,15 @@
 > Note: Introduced with GitLab 8.14
 
 When your GitLab installation needs to handle tens of thousands of background
-jobs, it can be convenient to prioritize queues that need to be executed
-immediately, e.g. user initiated actions like merging a Merge Request.
+jobs, it can be convenient to throttle queues that do not need to be executed
+immediately, e.g. long running jobs like Pipelines, thus allowing jobs that do
+need to be executed immediately to have access to more resources.
 
 In order to accomplish this, you can limit the amount of workers that certain
-slow running queues get can have available. This is what we call Sidekiq Job
+slow running queues can have available. This is what we call Sidekiq Job
 Throttling. Depending on your infrastructure, you might have different slow
-running queues, which is why you can choose which queues to throttle and by
-how much you want to throttle them.
+running queues, which is why you can choose which queues you want to throttle 
+and by how much you want to throttle them.
 
 These settings are available in the Application Settings of your GitLab
 installation.
@@ -24,8 +25,8 @@ and rounded up to the closest full integer.
 So, for example, you set the `:concurrency` to 25 and the `Throttling factor` to
 0.1, the maximum workers assigned to the selected queues would be 3.
 
-```
-limit = (factor * Sidekiq.options[:concurrency]).ceil
+```ruby
+queue_limit = (factor * Sidekiq.options[:concurrency]).ceil
 ```
 
 After enabling the job throttling, you will need to restart your GitLab
diff --git a/lib/gitlab/sidekiq_throttler.rb b/lib/gitlab/sidekiq_throttler.rb
index 771736e7606..d4d39a888e7 100644
--- a/lib/gitlab/sidekiq_throttler.rb
+++ b/lib/gitlab/sidekiq_throttler.rb
@@ -3,18 +3,20 @@ module Gitlab
     class << self
       def execute!
         if Gitlab::CurrentSettings.sidekiq_throttling_enabled?
-          current_application_settings.sidekiq_throttling_queues.each do |queue|
-            Sidekiq::Queue[queue].limit = set_limit
+          Gitlab::CurrentSettings.current_application_settings.sidekiq_throttling_queues.each do |queue|
+            Sidekiq::Queue[queue].limit = queue_limit
           end
         end
       end
 
       private
 
-      def set_limit
-        factor = current_application_settings.sidekiq_throttling_factor
-
-        (factor * Sidekiq.options[:concurrency]).ceil
+      def queue_limit
+        @queue_limit ||=
+          begin
+            factor = Gitlab::CurrentSettings.current_application_settings.sidekiq_throttling_factor
+            (factor * Sidekiq.options[:concurrency]).ceil
+          end
       end
     end
   end
diff --git a/spec/lib/gitlab/sidekiq_throttler_spec.rb b/spec/lib/gitlab/sidekiq_throttler_spec.rb
index ac4a64c0f43..ff32e0e699d 100644
--- a/spec/lib/gitlab/sidekiq_throttler_spec.rb
+++ b/spec/lib/gitlab/sidekiq_throttler_spec.rb
@@ -11,12 +11,6 @@ describe Gitlab::SidekiqThrottler do
     )
   end
 
-  describe '#set_limit' do
-    it 'returns the correct limit' do
-      expect(Gitlab::SidekiqThrottler.send(:set_limit)).to eq 4
-    end
-  end
-
   describe '#execute!' do
     it 'sets limits on the selected queues' do
       Gitlab::SidekiqThrottler.execute!
-- 
cgit v1.2.1