Chat Application

A scalable chat application built using Next.js, Tailwind, WebSockets, and Redis Pub/Sub for real-time communication. The app is designed to handle multiple rooms across different WebSocket servers, ensuring scalability and efficient message delivery.

When a user sends a message, the WebSocket server forwards it to the Redis Pub/Sub system, which broadcasts it to all WebSocket servers subscribed to that room. This architecture allows seamless communication between users across different servers.

Check out the live preview of the app: Chat App

Note: It might take a little time for messages to send initially since the WebSocket server is deployed on a free tier, which may cause some delay when restarting.

Features:

• Real-time messaging across multiple rooms.
• Scalable architecture utilizing WebSockets and Redis.
• Easy setup with Docker.

Tech Stack

• Next.js
• Tailwind
• Websockets
• Redis Pub/Sub
• Docker
• CI/CD for deployment to Docker Hub

Architecture

When a user selects a particular room, if there are no users already present in that room, the WebSocket server subscribes to that room. Any messages sent by the user are published to the Redis Pub/Sub system via the WebSocket server. From there, Redis broadcasts the message to all WebSocket servers subscribed to that room. This approach allows the app to scale efficiently.

Example:

Let's say two WebSocket servers are running: ws1 and ws2. A user connects to ws1 and joins room1. Since this is the first user in room1, ws1 subscribes to room1. If another user joins room1 via ws1, the server doesn't need to resubscribe.

If the first user sends a message in room1, it is forwarded from ws1 to Redis Pub/Sub, which broadcasts it back to ws1, where the message is delivered to the user(s) in room1.

Why is this important?

Later, if a third user connects to ws2 and joins room1, ws2 will subscribe to the room1 channel via the Pub/Sub system. This ensures that both WebSocket servers (ws1 and ws2) are synced with room1, enabling the app to scale across multiple servers efficiently.

Preview

Running the project locally

There is a docker-compose.yml in the project root. To run the app locally, use the following commands:

git clone https://github.com/Ayush272002/Chat-App.git
cd Chat-App
docker-compose up

Note: Environment variables can't be injected into the Next.js app during the Docker build process, as client-side variables need to be available before the build.

Contributing

Contributions are welcome! If you have suggestions for new features, bug fixes, or improvements, feel free to fork the repository and submit a pull request. For major changes, please open an issue first to discuss what you'd like to change.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contact

If you have any questions or suggestions, feel free to reach out.