Replace self-rolled statsd instrumention with localshred/nsa (#5118)

Gemfile

@@ -42,6 +42,7 @@ gem 'kaminari', '~> 1.0'
 gem 'link_header', '~> 0.0'
 gem 'mime-types', '~> 3.1'
 gem 'nokogiri', '~> 1.7'
+gem 'nsa', '~> 0.2'
 gem 'oj', '~> 3.0'
 gem 'ostatus2', '~> 2.0'
 gem 'ox', '~> 2.5'
@@ -64,7 +65,6 @@ gem 'sidekiq-bulk', '~>0.1.1'
 gem 'simple-navigation', '~> 4.0'
 gem 'simple_form', '~> 3.4'
 gem 'sprockets-rails', '~> 3.2', require: 'sprockets/railtie'
-gem 'statsd-instrument', '~> 2.1'
 gem 'twitter-text', '~> 1.14'
 gem 'tzinfo-data', '~> 1.2017'
 gem 'webpacker', '~> 3.0'

Gemfile.lock

@@ -289,6 +289,11 @@ GEM
       mini_portile2 (~> 2.2.0)
     nokogumbo (1.4.13)
       nokogiri
+    nsa (0.2.4)
+      activesupport (>= 4.2, < 6)
+      concurrent-ruby (~> 1.0.0)
+      sidekiq (>= 3.5.0)
+      statsd-ruby (~> 1.2.0)
     oj (3.3.5)
     openssl (2.0.5)
     orm_adapter (0.5.0)
@@ -483,7 +488,7 @@ GEM
     sshkit (1.14.0)
       net-scp (>= 1.1.2)
       net-ssh (>= 2.8.0)
-    statsd-instrument (2.1.4)
+    statsd-ruby (1.2.1)
     strong_migrations (0.1.9)
       activerecord (>= 3.2.0)
     temple (0.8.0)
@@ -578,6 +583,7 @@ DEPENDENCIES
   microformats (~> 4.0)
   mime-types (~> 3.1)
   nokogiri (~> 1.7)
+  nsa (~> 0.2)
   oj (~> 3.0)
   ostatus2 (~> 2.0)
   ox (~> 2.5)
@@ -617,7 +623,6 @@ DEPENDENCIES
   simple_form (~> 3.4)
   simplecov (~> 0.14)
   sprockets-rails (~> 3.2)
-  statsd-instrument (~> 2.1)
   strong_migrations
   twitter-text (~> 1.14)
   tzinfo-data (~> 1.2017)

config/environments/production.rb

@@ -90,11 +90,6 @@ Rails.application.configure do
 
   config.action_mailer.delivery_method = ENV.fetch('SMTP_DELIVERY_METHOD', 'smtp').to_sym
 
-  config.to_prepare do
-    StatsD.backend = StatsD::Instrument::Backends::NullBackend.new if ENV['STATSD_ADDR'].blank?
-    Sidekiq::Logging.logger.level = Logger::WARN
-  end
-
   config.action_dispatch.default_headers = {
     'Server'                 => 'Mastodon',
     'X-Frame-Options'        => 'DENY',

config/initializers/statsd.rb

@@ -1,18 +1,15 @@
 # frozen_string_literal: true
-RESERVED_CHARACTERS_REGEX = /[\:\|\@]/
 
-StatsD.prefix              = 'mastodon'
-StatsD.default_sample_rate = 1
+if ENV['STATSD_ADDR'].present?
+  host, port = ENV['STATSD_ADDR'].split(':')
 
-def clean_name(str)
-  str.gsub('::', '.').gsub(RESERVED_CHARACTERS_REGEX, '_')
-end
-
-ActiveSupport::Notifications.subscribe(/performance/) do |name, _start, _finish, _id, payload|
-  action      = payload[:action] || :increment
-  measurement = payload[:measurement]
-  value       = payload[:value]
-  key_name    = clean_name("#{name}.#{measurement}")
-
-  StatsD.send(action.to_s, key_name, (value || 1))
+  statsd = ::Statsd.new(host, port)
+  statsd.namespace = ['Mastodon', Rails.env].join('.')
+
+  ::NSA.inform_statsd(statsd) do |informant|
+    informant.collect(:action_controller, :web)
+    informant.collect(:active_record, :db)
+    informant.collect(:cache, :cache)
+    informant.collect(:sidekiq, :sidekiq)
+  end
 end