Split Rails Example 2

A simple Rails application to demonstrate the Split gem for A/B testing.

Overview

This application provides a single demo page that showcases three A/B test experiments:

1. Background Color: white, lightblue, or lightgreen
2. Heading Font: serif, sans-serif, or monospace
3. Layout Style: centered, left, or right alignment

Features

• Simple, single-view demo application
• 3 visual A/B test experiments that are immediately visible
• Split Dashboard integration for viewing experiment results
• Goal tracking when users click the demo button

Requirements

• Docker & Docker Compose (recommended)
• Or: Ruby 3.3+, Rails 8.1+, Redis

Architecture

Docker Compose Setup

graph LR
    Browser[Browser] -->|http://localhost:8080| Nginx[nginx<br/>Load Balancer]
    Nginx -->|Round-robin| App1[app1<br/>Puma :3000]
    Nginx -->|Round-robin| App2[app2<br/>Puma :3000]
    Nginx -->|Round-robin| App3[app3<br/>Puma :3000]
    App1 -->|Session Data| Redis[(Redis)]
    App2 -->|Session Data| Redis
    App3 -->|Session Data| Redis

Loading

This setup simulates a production-like environment with multiple independent Puma instances behind an nginx load balancer.

Setup

Option 1: Docker Compose (Recommended)

1. Start the application:

docker-compose up --build

2. Visit the application:

• Demo page: http://localhost:8080
• Split Dashboard: http://localhost:8080/split
  • Username: admin
  • Password: secret

3. View logs from all instances:

docker-compose logs -f app1 app2 app3

You'll see requests being distributed across three Puma instances (app1, app2, app3), which helps reproduce issues with Split's multi-server deployment.

4. Stop the application:

docker-compose down

Option 2: Local Development

1. Install dependencies:

bundle install

2. Start Redis:

redis-server

3. Start the Rails server:

bin/rails server

4. Visit the application:

• Demo page: http://localhost:3000
• Split Dashboard: http://localhost:3000/split
  • Username: admin
  • Password: secret

A/B Test Experiments

Background Color

• Alternatives: white, lightblue, lightgreen
• Goal: button_clicked

Heading Font

• Alternatives: serif, sans-serif, monospace
• Goal: button_clicked

Layout Style

• Alternatives: centered, left, right
• Goal: button_clicked

Usage

1. Open the demo page in different browsers or incognito windows to see different variations
2. Click the "Click Me to Track Goal!" button to track the goal
3. Visit the Split Dashboard to see experiment results and statistics

Testing

Testing A/B Experiments

1. Clear your browser cookies or use incognito mode
2. Refresh the page multiple times to see different variations
3. Click the goal button to record conversions
4. Check the Split Dashboard to see results

Testing Load Balancing (Docker Compose)

To verify that requests are being distributed across multiple Puma instances:

# Send multiple requests and observe the distribution
for i in {1..20}; do
  curl -s http://localhost:8080 >/dev/null
  sleep 0.1
done

# Watch the logs to see different instances handling requests
docker-compose logs -f app1 app2 app3

You should see requests being handled by different instances (app1, app2, app3) in the logs.