⚡ Redis Circuit Breaker Example

🛠️ A minimal distributed circuit breaker implementation using Redis
🚦 Built for service-to-service communication with simple gateway + microservices architecture

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🌉 Architecture Overview

graph TD
    Client -->|Request| Gateway
    Gateway -->|Redirect| ProfileService
    ProfileService -->|Fetch Auth Info| AuthService
    subgraph Redis
        CBState[(Circuit Breaker State)]
    end
    ProfileService -->|State Check| CBState

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✨ Features

• ✅ Simple Gateway to route requests
• ✅ Two microservices: AuthService and ProfileService
• ✅ Circuit Breaker logic at ProfileService to manage AuthService calls
• ✅ Redis used for:
  • 🔁 Shared state management (failures, open/close logic)
  • 🌐 Distributed control across instances

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🚦 Circuit Breaker Flow

            .---------------------------.
            |  ProfileService          |
            |--------------------------|
Request --> | Is Circuit Open?         |
            |     |                    |
            |    No                    |
            |     ↓                    |
            | Call Auth Service        |
            |     |                    |
            |  Success?                |
            |     |                    |
            |    Yes ----------------> Return Response
            |     ↓
            |  Increment Failure Count
            |     |
            |  Threshold Reached?
            |     ↓
            |   Open Circuit (Redis)
            '---------------------------'

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📦 Project Structure

📦project-root
 ┣ 📁gateway
 ┃ ┗ 📄index.js
 ┣ 📁auth-service
 ┃ ┗ 📄auth.js
 ┣ 📁profile-service
 ┃ ┗ 📄profile.js  <- Contains Circuit Breaker logic
 ┣ 📁redis
 ┣ 📄README.md

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🔧 Custom Logic

• The circuit breaker stores:
  • ✅ Failure count
  • ✅ Last failure timestamp
  • ✅ Cooldown duration
• These are used to determine:
  • 🔁 When to retry
  • 🔒 When to stop calling AuthService

Redis Keys:

cb:auth:state         // OPEN / CLOSED
cb:auth:failures      // Number of failed requests
cb:auth:lastFailure   // Timestamp of last failure

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🧩 Future Enhancements

• 🧠 Auto-recovery based on success ratio
• 🔌 Pluggable strategy for breaker logic
• ⚙️ adding correct fallback result

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🎬 Request Flow

Request ---> 🌉 Gateway ---> 👤 ProfileService ---❓---> 🔐 AuthService
                                  |     ▲
                                  ▼     |
                             🧠 Circuit Breaker (Redis)
                                  |
                         [ OPEN 🔴 / CLOSED 🟢 ]

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🚀 Quick Start

# 1. Clone the repository
git clone https://github.com/your-username/redis-circuit-breaker.git
cd circuit-breaker-redis

# 2. Copy the environment file
cp .env.template .env

# 3. Install dependencies for each service
cd gateway && pnpm install
cd ../auth && pnpm install
cd ../profile && pnpm install

# 4. Start everything with Docker Compose
cd ..  # back to project root
docker-compose up

✅ Make sure Redis is running via Docker Compose.
⚙️ You can modify Redis or service ports in .env as needed.

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🧠 Tip: This repo shows how you can build your own Resilience Layer without 3rd-party libraries using pure Node.js and Redis.

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📜 License

MIT © 2025