220: Improve Rails perf 5-10x

lessons/220/rails-app/.gitignore

@@ -31,3 +31,5 @@
 
 # Ignore master key for decrypting credentials and more.
 /config/master.key
+
+/.idea

lessons/220/rails-app/Dockerfile

@@ -60,4 +60,4 @@ ENTRYPOINT ["/rails/bin/docker-entrypoint"]
 
 # Start the server by default, this can be overwritten at runtime
 EXPOSE 8080
-CMD ["./bin/rails", "server"]
+CMD ["./bin/rails", "server", "-b", "0.0.0.0", "-p", "8080"]

lessons/220/rails-app/Gemfile

@@ -1,47 +1,12 @@
 source "https://rubygems.org"
 
-gem 'pg'
+gem "falcon"
+gem "oj"
+gem "pg"
+gem "prometheus-client"
+gem "rage-rb"
 
-gem 'prometheus-client'
-
-# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
-gem "rails", "~> 7.2.1", ">= 7.2.1.2"
-# Use sqlite3 as the database for Active Record
-gem "sqlite3", ">= 1.4"
-# Use the Puma web server [https://github.com/puma/puma]
-gem "puma", ">= 5.0"
-# Build JSON APIs with ease [https://github.com/rails/jbuilder]
-# gem "jbuilder"
-# Use Redis adapter to run Action Cable in production
-# gem "redis", ">= 4.0.1"
-
-# Use Kredis to get higher-level data types in Redis [https://github.com/rails/kredis]
-# gem "kredis"
-
-# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
-# gem "bcrypt", "~> 3.1.7"
-
-# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem "tzinfo-data", platforms: %i[ windows jruby ]
+gem "rails"
 
 # Reduces boot times through caching; required in config/boot.rb
 gem "bootsnap", require: false
-
-# Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
-# gem "image_processing", "~> 1.2"
-
-# Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin Ajax possible
-# gem "rack-cors"
-
-group :development, :test do
-  # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
-  gem "debug", platforms: %i[ mri windows ], require: "debug/prelude"
-
-  # Static analysis for security vulnerabilities [https://brakemanscanner.org/]
-  gem "brakeman", require: false
-
-  # Omakase Ruby styling [https://github.com/rails/rubocop-rails-omakase/]
-  gem "rubocop-rails-omakase", require: false
-end
-
-

lessons/220/rails-app/app/controllers/application_controller.rb

@@ -1,2 +1,2 @@
-class ApplicationController < ActionController::API
+class ApplicationController < ActionController::Metal
 end

lessons/220/rails-app/app/controllers/devices_controller.rb

@@ -1,56 +1,34 @@
-class DevicesController < ApplicationController
-  before_action :set_device, only: %i[ show update destroy ]
+# frozen_string_literal: true
 
+class DevicesController < ApplicationController
   # GET /devices
   def index
     devices = [
-      Device.new(id: 1, uuid: "9add349c-c35c-4d32-ab0f-53da1ba40a2a", mac: "5F-33-CC-1F-43-82", firmware: "2.1.6", created_at: "2024-5-28T15:21:51.137Z", updated_at: "2024-5-28T15:21:51.137Z"),
-      Device.new(id: 2, uuid: "d2293412-36eb-46e7-9231-af7e9249fffe", mac: "E7-34-96-33-0C-4C", firmware: "1.0.3", created_at: "2024-01-28T15:20:51.137Z", updated_at: "2024-01-28T15:20:51.137Z"),
-      Device.new(id: 3, uuid: "eee58ca8-ca51-47a5-ab48-163fd0e44b77", mac: "68-93-9B-B5-33-B9", firmware: "4.3.1", created_at: "2024-8-28T15:18:21.137Z", updated_at: "2024-8-28T15:18:21.137Z")
+      Device.new(id: 1, uuid: "9add349c-c35c-4d32-ab0f-53da1ba40a2a", mac: "5F-33-CC-1F-43-82", firmware: "2.1.6", created_at: "2024-5-28T15:21:51.137Z", updated_at: "2024-5-28T15:21:51.137Z").attributes,
+      Device.new(id: 2, uuid: "d2293412-36eb-46e7-9231-af7e9249fffe", mac: "E7-34-96-33-0C-4C", firmware: "1.0.3", created_at: "2024-01-28T15:20:51.137Z", updated_at: "2024-01-28T15:20:51.137Z").attributes,
+      Device.new(id: 3, uuid: "eee58ca8-ca51-47a5-ab48-163fd0e44b77", mac: "68-93-9B-B5-33-B9", firmware: "4.3.1", created_at: "2024-8-28T15:18:21.137Z", updated_at: "2024-8-28T15:18:21.137Z").attributes
     ]
-
-    render json: devices
-  end
 
-  # GET /devices/1
-  def show
-    render json: @device
+    build_response(devices, 200)
   end
 
   # POST /devices
   def create
-    @device = Device.new(device_params)
-    @device.uuid = SecureRandom.uuid
-
-    if @device.save
-      render json: @device, status: :created, location: @device
-    else
-      render json: @device.errors, status: :unprocessable_entity
-    end
-  end
+    device = Device.new(params.slice(:mac, :firmware))
+    device.uuid = SecureRandom.uuid
 
-  # PATCH/PUT /devices/1
-  def update
-    if @device.update(device_params)
-      render json: @device
+    if device.save
+      build_response(device, 201)
     else
-      render json: @device.errors, status: :unprocessable_entity
+      build_response(device.errors, 422)
     end
   end
 
-  # DELETE /devices/1
-  def destroy
-    @device.destroy!
-  end
-
   private
-    # Use callbacks to share common setup or constraints between actions.
-    def set_device
-      @device = Device.find(params[:id])
-    end
 
-    # Only allow a list of trusted parameters through.
-    def device_params
-      params.require(:device).permit(:uuid, :mac, :firmware)
-    end
+  def build_response(body, status_code)
+    self.content_type = "application/json"
+    self.status = status_code
+    self.response_body = body.to_json
+  end
 end

lessons/220/rails-app/app/models/device.rb

@@ -1,2 +1,9 @@
 class Device < ApplicationRecord
+  def save
+    result = nil
+
+    PrometheusClient.db_histogram.observe(Benchmark.realtime { result = super })
+
+    result
+  end
 end

lessons/220/rails-app/bin/iodine

@@ -0,0 +1,27 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+#
+# This file was generated by Bundler.
+#
+# The application 'iodine' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
+
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+bundle_binstub = File.expand_path("bundle", __dir__)
+
+if File.file?(bundle_binstub)
+  if File.read(bundle_binstub, 300).include?("This file was generated by Bundler")
+    load(bundle_binstub)
+  else
+    abort("Your `bin/bundle` was not generated by Bundler, so this binstub cannot run.
+Replace `bin/bundle` by running `bundle binstubs bundler --force`, then run this command again.")
+  end
+end
+
+require "rubygems"
+require "bundler/setup"
+
+load Gem.bin_path("rage-iodine", "iodine")

lessons/220/rails-app/config.ru

@@ -1,14 +1,9 @@
 # This file is used by Rack-based servers to start the application.
 require 'rack'
-require 'prometheus/middleware/collector'
 require 'prometheus/middleware/exporter'
 
-use Rack::Deflater
-use Prometheus::Middleware::Collector
 use Prometheus::Middleware::Exporter
 
-run ->(_) { [200, {'content-type' => 'text/html'}, ['OK']] }
-
 require_relative "config/environment"
 
 run Rails.application

lessons/220/rails-app/config/application.rb

@@ -1,6 +1,7 @@
 require_relative "boot"
 
-require "rails/all"
+require "active_record/railtie"
+require "action_controller/railtie"
 
 # Require the gems listed in Gemfile, including any gems
 # you've limited to :test, :development, or :production.
@@ -28,5 +29,33 @@ class Application < Rails::Application
     # Middleware like session, flash, cookies can be added back manually.
     # Skip views, helpers and assets when generating a new resource.
     config.api_only = true
+    config.secret_key_base = 'secret'
+
+    config.middleware.delete Rack::Sendfile
+    config.middleware.delete ActionDispatch::Static
+    config.middleware.delete ActionDispatch::Executor
+    config.middleware.delete Rack::Runtime
+    config.middleware.delete ActionDispatch::RequestId
+    config.middleware.delete ActionDispatch::RemoteIp
+    config.middleware.delete Rails::Rack::Logger
+    config.middleware.delete ActionDispatch::ShowExceptions
+    config.middleware.delete ActionDispatch::DebugExceptions
+    config.middleware.delete ActionDispatch::Callbacks
+    config.middleware.delete Rack::Head
+    config.middleware.delete Rack::ConditionalGet
+    config.middleware.delete Rack::ETag
+
+    require 'rage/fiber'
+    require 'rage/fiber_scheduler'
+    require 'rage/middleware/fiber_wrapper'
+    config.middleware.use Rage::FiberWrapper
+
+    Oj.default_options = { mode: :compat }
+    Oj.optimize_rails
+
+    Iodine.workers = ENV.fetch('WORKERS_NUM', 2).to_i
+    Iodine.threads = 1
+
+    Iodine.on_state(:after_fork) { RubyVM::YJIT.enable }
   end
 end

lessons/220/rails-app/config/environments/development.rb

@@ -29,16 +29,16 @@
   end
 
   # Store uploaded files on the local file system (see config/storage.yml for options).
-  config.active_storage.service = :local
+  # config.active_storage.service = :local
 
   # Don't care if the mailer can't send.
-  config.action_mailer.raise_delivery_errors = false
+  # config.action_mailer.raise_delivery_errors = false
 
   # Disable caching for Action Mailer templates even if Action Controller
   # caching is enabled.
-  config.action_mailer.perform_caching = false
+  # config.action_mailer.perform_caching = false
 
-  config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
+  # config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
 
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
@@ -56,7 +56,7 @@
   config.active_record.verbose_query_logs = true
 
   # Highlight code that enqueued background job in logs.
-  config.active_job.verbose_enqueue_logs = true
+  # config.active_job.verbose_enqueue_logs = true
 
   # Raises error for missing translations.
   # config.i18n.raise_on_missing_translations = true