Problem Description
Design a URL shortening service like TinyURL or bit.ly. The service should be able to handle millions of URLs and provide fast lookups.
Requirements
- Generate unique short URLs
- Handle millions of URLs
- Fast URL lookups
- Track click analytics
- Handle concurrent requests
System Architecture
The system consists of the following components:
- Load Balancer: Distributes traffic across multiple servers
- Application Servers: Handle URL shortening and redirection
- Database: Stores URL mappings and analytics
- Cache: Improves lookup performance
- Analytics Service: Tracks URL clicks
Key Components
URL Generation
Use base62 encoding (A-Z, a-z, 0-9) to generate unique 7-character URLs. This provides 62^7 ≈ 3.5 trillion unique URLs.
Database Schema
URLs {
id: string (primary key)
long_url: string
short_url: string
created_at: timestamp
clicks: number
}Scalability Considerations
Horizontal Scaling
Use multiple application servers behind a load balancer to handle increased traffic.
Caching Strategy
Implement Redis caching for frequently accessed URLs to reduce database load.