Website Visit Counter

Overview

The project efficiently tracks page visits using caching strategies, Redis for global caching, and scalability techniques such as sharding, batching, and consistent hashing.

Features

• Basic Visit Counter: Tracks visits to a page.
• Redis Integration: Stores visit counts persistently.
• Application Layer Caching: Reduces redundant Redis reads.
• Batching Write Requests: Optimizes write operations.
• Redis Sharding: Ensures scalability and fault tolerance.

Tech Stack

• Backend: FastAPI (Python)
• Database: Redis
• Containerization: Docker

Installation & Setup

Prerequisites

Ensure the following are installed:

• Python 3.8+
• Docker & Docker Compose
• Redis

Steps to Run

1. Clone this repository:

git clone https://github.com/Shreshthaaa/Website-Visit-Counter.git
cd Website-Visit-Counter

2. Set up environment variables (create a .env file in the root directory):

3. Start the application and Redis instances using Docker:

docker-compose up --build

4. The FastAPI server will be available at http://localhost:8000

API Endpoints

1. Record a Page Visit

• Endpoint: POST /visit/{page_id}
• Description: Increments the visit count for a given page.
• Response:

{ "status": "success", "message": "Visit recorded for page {page_id}" }

2. Get Visit Count

• Endpoint: GET /visits/{page_id}
• Description: Retrieves the visit count for a specific page.
• Response Format:

{ "count": 123, "served_via": "redis_7070" }

• served_via: Shows if data was fetched from in-memory cache or a Redis shard.

System Design

1. Application Layer Caching

• Uses an in-memory dictionary to temporarily store visit counts.
• Cache expiry time: 5 seconds.
• If cache expires, fetches count from Redis.

2. Batching Write Requests

• Stores visit counts in an in-memory buffer before writing to Redis.
• Flushes the buffer to Redis every 30 seconds to reduce write operations.

3. Redis Sharding with Consistent Hashing

• Distributes keys across multiple Redis instances (redis_7070, redis_7071).
• Ensures scalability and fault tolerance.