A distributed, cloud-native notification microservice built with FastAPI (Python), integrating Kafka, Redis, and MySQL, orchestrated with Docker Compose.

1. Send Notifications: Asynchronous processing via Kafka.
2. Status Tracking: Stores status in MySQL and Redis.
3. Idempotency: Redis-based idempotency key support to prevent duplicate processing.
4. Rate Limiting: Redis-based rate limiting (60 requests/minute).

• Language: Python 3.11 (FastAPI)
• Database: MySQL 8 (Async SQLAlchemy)
• Broker: Kafka (AIOKafka)
• Cache/KV: Redis 7 (Async)
• Containerization: Docker & Docker Compose

• notification-service: FastAPI Application (Port 8000)
• mysql: Database (Port 3306)
• redis: Cache & Rate Limiting (Port 6379)
• kafka + zookeeper: Message Broker (Port 9094)

docker compose up -d --build

curl http://localhost:8000/health

curl -X POST "http://localhost:8000/api/notify?userId=1&msg=Hello"

Response: Queued Notification ID: <id>

curl "http://localhost:8000/api/notify/status?id=<id>"

for i in {1..70}; do 
  curl -X POST "http://localhost:8000/api/notify?userId=1&msg=Test-$i"; 
  echo; 
done

curl -X POST "http://localhost:8000/api/notify?userId=1&msg=Repeat" -H "Idempotency-Key: test-key-1"

Repeating the above command should return a duplicate request error.