README.md

Real-time Polling Application

A real-time polling application built with TypeScript, NodeJS, Express, WebSocket, Kafka, and Prisma.

Prerequisites

• Node.js (v18 or higher)
• Docker

Getting Started

1. Clone the repository

   git clone https://github.com/yshplsngh/polling-system.git
   cd polling-system

2. Start Kafka, Zookeeper, Postgres, and Backend

   docker-compose up

   • you have to stop local postgres service if it is running on port 5432.

3. Install Frontend Dependencies

   cd client
   npm install

4. Run Frontend

   cd client
   npm run dev

5. Access the application

   • Frontend: http://localhost:5173
   • Backend: http://localhost:4000

How this kakfa handle Concurrency and Failover Handling:

• The polling-topic is divided into 3 partitions. Each partition is consumed by only one consumer in the same consumer group, it enable the parallel processing of votes.
• Three consumers (kafkaConsumer1, kafkaConsumer2, kafkaConsumer3) are initialized in the same consumer group. so that they can concurrently consume the votes from different partitions.
• we can also add more group with more consumers, but I have not added in this project.
• I have added 1 Replication factor for 1 broker for fault tolerance.