Scale Chat

Scale Chat is a scalable chat app backend service utilizing Redis to enhance the scalability of web sockets, while leveraging Kafka to streamline the process of writing messages to the database, avoiding the need for individual write operations.

Architecture

DB

Folder Structure

.
├── README.md
├── github_assets
│   ├── DB Diagram.jpg
│   └── architecture.png
├── package-lock.json
├── package.json
├── prisma
│   ├── ca.pem
│   ├── example_key.pem
│   ├── migrations
│   │   ├── 20240502172518_init
│   │   │   └── migration.sql
│   │   ├── 20240504090739_init
│   │   │   └── migration.sql
│   │   ├── 20240504092402_update_tables
│   │   │   └── migration.sql
│   │   ├── 20240504105700_update_users_table
│   │   │   └── migration.sql
│   │   └── migration_lock.toml
│   └── schema.prisma
├── public
│   ├── auth
│   │   └── index.html
│   └── chat
│       └── index.html
└── src
    ├── config
    │   ├── cookies.config.js
    │   ├── kafka.config.js
    │   └── redis.config.js
    ├── controllers
    │   ├── message
    │   │   └── message.controller.js
    │   └── user
    │       ├── userAuth.controller.js
    │       └── userDetails.controller.js
    ├── index.js
    ├── middlewares
    │   └── auth.middleware.js
    ├── routes
    │   ├── message.routes.js
    │   ├── user.routes.js
    │   └── version1.routes.js
    ├── service
    │   ├── cronJob.js
    │   ├── kafka
    │   │   ├── admin.js
    │   │   ├── client.js
    │   │   ├── consumer.js
    │   │   └── producer.js
    │   ├── prisma.js
    │   ├── redis.js
    │   └── socket.js
    └── utils
        ├── ApiError.js
        ├── ApiResponse.js
        ├── asyncHandler.js
        ├── bcrypt.js
        ├── constants.js
        ├── generateChatPair.js
        ├── jwt.js
        └── socketManager.js

Run Locally

Clone the project

git clone https://github.com/anuj-thakur-513/ScaleChat.git

Go to the project directory

cd ScaleChat

Install dependencies

npm install

Install PM2

npm install pm2@latest -g

Start Zookeper Container and expose PORT 2181

docker run -p 2181:2181 zookeeper

Start Kafka Container, expose PORT 9092 and setup ENV variables

docker run -p 9092:9092 \
-e KAFKA_ZOOKEEPER_CONNECT=<PRIVATE_IP>:2181 \
-e KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://<PRIVATE_IP>:9092 \
-e KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1 \
confluentinc/cp-kafka

Change .env.example to .env and update the variables in the file

Replace ./prisma/example_key.pem with your own DB key

Run Kafka Admin to create topic in your local Kafka Server

npm run kafka-admin

Spin up the Server on PORT 8000

npm start or npm run dev

Run the Application in Cluster Mode

pm2 start src/index.js -i max