URL Shortener

This project provides a URL shortening service that converts long URLs into shorter ones.

• Users submit a long URL to receive a shortened URL.
• Users can use the shortened URL to redirect to the original URL.

Functional Requirements

1. URL Shortening : Users submit a long URL to receive a shortened URL.
2. URL Redirection : Users can use the shortened URL to be redirected to the original URL.

Non-Functional Requirements

1. High Scalability: Load balancer, DB replication, Redis cluster.
2. High Availability: Load balancer, Auto scaling, DB replication, Redis cluster, Health check
3. Low Latency: Hybrid cache, DB replication, Message Queue
4. Uniqueness Guarantee: Base58, ID Generator

Technology Stack

• Java 21
• Kotlin 1.9.25
• Spring Boot 3.4.1
• PostgreSQL 17
• Redis 8
• Caffeine
• Docker
• JUnit 5

Installation and Execution

Run using Docker:

make run

API Specifications

1. URL Shortening

URL shortening API to shorten a long URL

POST /api/v1/shorten

Request Body:

{
   "longUrl": "https://example.com/long-url",
   "userId": 1
}

Response:

Status: 201

Status:

• 201 Create: Successfully created a shortened URL.
• 400 Bad Request: Invalid URL input.

2. URL Redirection

API for redirecting to the original URL with the shortened URL

GET /{hash}

Response:

HTTP/1.1 301 Moved Permanently
Location: "https://example.com/long-url"

3. Find URLs by userId

Find the shorten and original URLs that user have

GET /api/v1/users/{userId}/urls

Response:

[
  {
    "id": 1,
    "longUrl": "http://amazon.com",
    "shortUrl": "http://localhost:8080/3gXe",
    "hash": "3gXe",
    "userId": 1,
    "createdAt": "2025-01-06T00:14:12.429006",
    "updatedAt": "2025-01-06T00:14:12.429006"
  },
]

Database Schema

URL Table

Field Name	Type	Description
id	SERIAL	Primary key
long_url	VARCHAR	Original URL
short_url	VARCHAR	Shortened URL
hash	VARCHAR	Hash for short URL
userId	BIGINT	User Identity
createdAt	TIMESTAMP	Creation date time
updatedAt	TIMESTAMP	Modification date time

Testing

Run tests using JUnit 5:

make test

Current Architecture

High-level design of current architecture

Future Architecture

High-level design of future architecture

• Response Code
• Unique URL
• Database
• Cache
• ID Generator
• Message Queue
• Rate Limiter
• Asynchronous, Non-Blocking

Performance Test

Test Machine Specifications

• Processor: Apple M3 Pro
• Cores: 11 cores
• Memory: 36GB

Load Test APIs

1. URL Shortening API: generate a shortened version of a provided URL
2. Short URL resolution API: resolves a shortened URL and redirect the user to the origin URL