"Оптимизация" бэкенда

Gemfile

@@ -14,7 +14,7 @@ group :production do
 end
 
 gem "psych", "< 4"
-gem "skylight"
+# gem "skylight"
 
 gem "actionpack-action_caching", "~> 1.2"
 gem "active_record_union", "~> 1.3"
@@ -68,6 +68,7 @@ gem "omniauth", "~> 1.9"
 gem "omniauth-github", "~> 1.3"
 gem "omniauth-twitter", "~> 1.4"
 gem "pg", "~> 1.1"
+gem "pghero", "2.8.3"
 gem "pry", "~> 0.12"
 gem "pry-rails", "~> 0.3"
 gem "puma", "~> 3.12"
@@ -115,6 +116,7 @@ group :development do
   gem "guard", "~> 2.15", require: false
   gem "guard-livereload", "~> 2.5", require: false
   gem "guard-rspec", "~> 4.7", require: false
+  gem "rack-mini-profiler", "3.3.1", require: false
   gem "rb-fsevent", "~> 0.10", require: false
   gem "web-console", "~> 3.7"
 end

Gemfile.lock

@@ -649,6 +649,8 @@ GEM
     nio4r (2.7.4)
     nokogiri (1.15.7-aarch64-linux)
       racc (~> 1.4)
+    nokogiri (1.15.7-x86_64-linux)
+      racc (~> 1.4)
     notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -697,6 +699,8 @@ GEM
       ast (~> 2.4.1)
       racc
     pg (1.5.9)
+    pghero (2.8.3)
+      activerecord (>= 5)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -726,6 +730,8 @@ GEM
     rack (2.2.11)
     rack-host-redirect (1.3.0)
       rack
+    rack-mini-profiler (3.3.1)
+      rack (>= 1.2.0)
     rack-protection (2.2.4)
       rack
     rack-proxy (0.7.7)
@@ -908,10 +914,6 @@ GEM
       tilt (~> 2.0)
     sitemap_generator (6.3.0)
       builder (~> 3.0)
-    skylight (4.3.2)
-      skylight-core (= 4.3.2)
-    skylight-core (4.3.2)
-      activesupport (>= 4.2.0)
     slack-notifier (2.4.0)
     smart_properties (1.17.0)
     snaky_hash (2.0.1)
@@ -1011,6 +1013,7 @@ GEM
 
 PLATFORMS
   aarch64-linux
+  x86_64-linux
 
 DEPENDENCIES
   actionpack-action_caching (~> 1.2)
@@ -1088,6 +1091,7 @@ DEPENDENCIES
   omniauth-twitter (~> 1.4)
   parallel_tests (~> 2.27)
   pg (~> 1.1)
+  pghero (= 2.8.3)
   pry (~> 0.12)
   pry-byebug (~> 3.7)
   pry-rails (~> 0.3)
@@ -1098,6 +1102,7 @@ DEPENDENCIES
   pusher (~> 1.3)
   pusher-push-notifications (~> 1.0)
   rack-host-redirect (~> 1.3)
+  rack-mini-profiler (= 3.3.1)
   rack-timeout (~> 0.5)
   rails (~> 5.1.6)
   rails-assets-airbrake-js-client (~> 1.5)!
@@ -1126,7 +1131,6 @@ DEPENDENCIES
   simplecov (~> 0.16)
   sinatra (~> 2.0)
   sitemap_generator (~> 6.0)
-  skylight
   slack-notifier (~> 2.3)
   sprockets (~> 3.7)
   staccato (~> 0.5)

app/views/stories/_main_stories_feed.html.erb

@@ -55,7 +55,9 @@
     <% if !user_signed_in? && i == 4 %>
       <%= render "stories/sign_in_invitation" %>
     <% end %>
-    <%= render "articles/single_story", story: story %>
+    <% cache("single-story-#{story.cache_key}") do %>
+      <%= render "articles/single_story", story: story %>
+    <% end %>
   <% end %>
 <% end %>
 <% if @stories.size > 1 %>

case_study.md

@@ -0,0 +1,37 @@
+## Оптимизация бэкенда
+
+> Рассмотрите гипотезу о том, что можно закешировать `<%= render "articles/single_story", story: story %>` в `_main_stories_feed.html.erb` и это даст заметный эффект. (В этот паршл входят счётчики лайков и комментариев, они не заморозятся?)
+
+Если использовать `story.cache_key`, то по идее не заморозятся, т.к. счётчик берётся из поля модели (`cache_counter`).
+
+Без кэша:
+
+```
+Concurrency Level:      5
+Time taken for tests:   19.728 seconds
+Complete requests:      100
+Failed requests:        0
+Total transferred:      15922500 bytes
+HTML transferred:       15875800 bytes
+Requests per second:    5.07 [#/sec] (mean)
+Time per request:       986.417 [ms] (mean)
+Time per request:       197.283 [ms] (mean, across all concurrent requests)
+Transfer rate:          788.17 [Kbytes/sec] received
+```
+
+С кэшем:
+
+```
+Concurrency Level:      5
+Time taken for tests:   11.927 seconds
+Complete requests:      100
+Failed requests:        0
+Total transferred:      15788300 bytes
+HTML transferred:       15741600 bytes
+Requests per second:    8.38 [#/sec] (mean)
+Time per request:       596.328 [ms] (mean)
+Time per request:       119.266 [ms] (mean, across all concurrent requests)
+Transfer rate:          1292.77 [Kbytes/sec] received
+```
+
+Как будто бы помогло. Проверяла с отключеным rack-mini-profiler (и т.д. штуками)

config/initializers/rack_mini_profiler.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+if Rails.env.development?
+  require "rack-mini-profiler"
+
+  # The initializer was required late, so initialize it manually.
+  Rack::MiniProfilerRails.initialize!(Rails.application)
+end

config/routes.rb

@@ -7,6 +7,8 @@
     registrations: "registrations"
   }
 
+  mount PgHero::Engine, at: "pghero"
+
   authenticated :user, ->(user) { user.admin? } do
     mount DelayedJobWeb, at: "/delayed_job"
   end