Rust Load Balancer - CIS 1905 Final Project

A high-performance HTTP load balancer implementation in Rust, featuring multiple load balancing strategies and detailed metrics tracking.

Features

Load Balancing Strategies

• Round Robin: Simple rotation through servers with request distribution tracking
• Least Connections: Routes based on active connection count with success rate monitoring
• Weighted Round Robin: Supports server weights (random 1-10 if not specified) with distribution tracking
• IP Hash: Consistent hashing based on client IP for session affinity

Metrics and Monitoring

• Real-time metrics for each algorithm:
  • Round Robin: Request counts and distribution percentages
  • Least Connections: Active connections, total requests, success rates
  • Weighted Round Robin: Server weights, request distribution
  • IP Hash: Request distribution and IP mappings
• Metrics accessible via HTTP endpoint (/metrics)
• Automatic metrics display on shutdown

Performance Features

• Async I/O with Tokio
• Connection pooling
• Configurable connection limits
• Graceful shutdown handling

Quick Start

1. Clone the repository:

git clone https://github.com/vedanshgoenka/rust-load-balancer.git
cd rust-load-balancer

2. Run the complete setup (load balancer, servers, and test load):

./start_all.sh

3. Try different algorithms:

./start_all.sh --algorithm round-robin
./start_all.sh --algorithm least-connections
./start_all.sh --algorithm weighted-round-robin
./start_all.sh --algorithm ip-hash

Component Scripts

• start_all.sh: Launches complete setup with load testing
• start_balancer.sh: Starts only the load balancer
• start_server.sh: Launches backend servers
• start_generator.sh: Runs load testing
• start_client_server.sh: Starts both client and server components

Configuration

Load Balancer

• Port: Default 8000
• Algorithms: round-robin, least-connections, weighted-round-robin, ip-hash
• Connection limit: 500 concurrent connections

Backend Servers

• Default ports: 8001-8020
• Configurable response delays for GET/POST
• Health check support

Load Generator

• Configurable request count
• Adjustable concurrent clients
• GET/POST ratio control

Metrics

Access metrics via:

1. HTTP endpoint: curl http://localhost:8000/metrics
2. Automatic display on Ctrl+C
3. Final metrics after test completion

Example metrics output:

127.0.0.1:8001: Active: 5, Total: 100, Success: 95, Rate: 95.0%
127.0.0.1:8002: Weight: 8, Requests: 150, Distribution: 30.0%

Dependencies

[dependencies]
tokio = { version = "1.28", features = ["full"] }
clap = { version = "4.2", features = ["derive"] }
reqwest = { version = "0.11", features = ["json"] }
futures = "0.3"
rand = "0.8"

Project Structure

rust_load_balancer/
├── src/
│   ├── main.rs           # Entry point
│   ├── lib.rs           # Library exports
│   ├── algorithms/      # Load balancing algorithms
│   ├── balancer/       # Load balancer core
│   ├── server/         # Backend server
│   ├── client/         # Client implementation
│   └── generator/      # Load generator
├── scripts/
│   ├── start_all.sh
│   ├── start_balancer.sh
│   ├── start_server.sh
│   └── start_generator.sh

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Authors

• Richard Xue [email protected]
• Vedansh Goenka [email protected]