Rails installation and setup - Performance & Optimization

Performance: Rails installation and setup

MEDIUM IMPACT

This affects the initial page load speed and development environment responsiveness by determining how quickly Rails can start and serve requests.

Setting up a new Rails project for fast development and loading

Ruby on Rails

rails new myapp --skip-test --skip-system-test

Keeps Bootsnap enabled for faster boot times and uses default JavaScript and Turbolinks for better page load performance.

📈 Performance Gainreduces server startup time by up to 50%, improving LCP

Setting up a new Rails project for fast development and loading

Ruby on Rails

rails new myapp --skip-javascript --skip-turbolinks --skip-test --skip-system-test --skip-bootsnap

Skipping essential components like Bootsnap can slow down boot time and page load during development.

📉 Performance Costincreases server startup time by 1-2 seconds, affecting LCP during development

Performance Comparison

Pattern	Server Startup Time	Asset Compilation	Initial Response Time	Verdict
Minimal setup with Bootsnap	Fast (under 1s)	Optimized	Fast (under 200ms)	[OK] Good
Setup skipping Bootsnap	Slow (2-3s)	Unoptimized	Slower (400ms+)	[X] Bad

Rendering Pipeline

Rails installation and setup influence how quickly the server can start and respond, impacting the time before the browser receives HTML to render.

→Server Startup

→Initial HTML Response

→Asset Compilation

⚠️ BottleneckServer Startup and Asset Compilation

Core Web Vital Affected

LCP

This affects the initial page load speed and development environment responsiveness by determining how quickly Rails can start and serve requests.

Optimization Tips

1Always enable Bootsnap caching for faster server startup.

2Precompile assets before deployment to reduce initial load delays.

3Avoid skipping essential components that improve boot and response times.

Performance Quiz - 3 Questions

Which Rails setup option helps improve server startup time?

A Skip JavaScript setup

B Enable Bootsnap caching

C Skip system tests

D Use default gems without changes

DevTools: Network

How to check: Open DevTools, go to Network tab, reload the page, and observe the time to first byte (TTFB) and document load time.

What to look for: Look for fast TTFB and quick document load times indicating efficient server response and asset delivery.

Practice

1. What is the main purpose of running gem install rails in your terminal?

easy

A. To install the Rails framework on your computer

B. To create a new Rails project

C. To start the Rails server

D. To update Ruby to the latest version

Solution

1. Step 1: Understand the command gem install rails

   This command uses Ruby's package manager (gem) to install the Rails framework on your system.

2. Step 2: Differentiate from other commands

   Creating a project uses rails new, and starting the server uses rails server. Updating Ruby is separate.

3. Final Answer:

   To install the Rails framework on your computer -> Option A

4. Quick Check:

   Install Rails = gem install rails [OK]

Hint: Install Rails with gem install rails command [OK]

Common Mistakes:

• Confusing installation with project creation
• Trying to start server before installing Rails
• Mixing Ruby update with Rails installation

2. Which command correctly creates a new Rails application named myapp?

easy

A. rails create myapp

B. rails new myapp

C. gem new myapp

D. rails start myapp

Solution

1. Step 1: Identify the correct Rails command for project creation

   The command to create a new Rails app is rails new appname.

2. Step 2: Check each option

   rails create myapp uses 'create' which is incorrect. gem new myapp uses 'gem' which manages packages, not projects. rails start myapp uses 'start' which is for running the server.

3. Final Answer:

   rails new myapp -> Option B

4. Quick Check:

   Create app = rails new [OK]

Hint: Use rails new appname to create a project [OK]

Common Mistakes:

• Using 'rails create' instead of 'rails new'
• Confusing gem commands with Rails commands
• Trying to start app with wrong command

3. After running rails new blog and then cd blog, what happens when you run rails server?

medium

A. Starts a web server accessible at http://localhost:3000

B. Creates a new Rails project named blog

C. Installs Rails gems needed for the project

D. Displays an error because the server command is invalid

Solution

1. Step 1: Understand the rails server command

   This command starts the Rails web server so you can view your app in a browser.

2. Step 2: Confirm the server address

   By default, the server runs on port 3000 and is accessible at http://localhost:3000.

3. Final Answer:

   Starts a web server accessible at http://localhost:3000 -> Option A

4. Quick Check:

   rails server = start web server [OK]

Hint: rails server runs app at localhost:3000 [OK]

Common Mistakes:

• Thinking rails server creates a project
• Expecting gem installation during server start
• Assuming server command is invalid

4. You ran rails new myapp but got an error saying 'command not found: rails'. What is the most likely cause?

medium

A. Ruby is not installed on your system

B. You forgot to create the project folder manually

C. Rails gem is not installed or not in your PATH

D. You need to run rails server first

Solution

1. Step 1: Analyze the error 'command not found: rails'

   This error means the system cannot find the rails command, usually because the Rails gem is missing or not accessible.

2. Step 2: Check other options

   Creating a folder manually is not needed; Ruby missing would cause a different error; running server first is unrelated.

3. Final Answer:

   Rails gem is not installed or not in your PATH -> Option C

4. Quick Check:

   Missing rails gem = command not found [OK]

Hint: Install Rails gem before using rails commands [OK]

Common Mistakes:

• Assuming folder must be created manually
• Confusing Ruby absence with Rails command error
• Trying to run server before project exists

5. You want to create a new Rails app but skip installing all default gems to speed up setup. Which command should you use?

hard

A. rails new appname --skip-install

B. rails new appname --no-gems

C. gem install rails --skip-defaults

D. rails new appname --skip-bundle

Solution

1. Step 1: Identify the option to skip gem installation during project creation

   The --skip-bundle flag tells Rails to create the app without running bundle install which installs gems.

2. Step 2: Evaluate other options

   rails new appname --no-gems is invalid syntax, gem install rails --skip-defaults misuses gem install, rails new appname --skip-install is not a recognized flag.

3. Final Answer:

   rails new appname --skip-bundle -> Option D

4. Quick Check:

   Skip gem install = --skip-bundle [OK]

Hint: Use --skip-bundle to skip gem install on new app [OK]

Common Mistakes:

• Using invalid flags like --no-gems or --skip-install
• Trying to skip gem install with gem install command
• Confusing bundle install with rails new options