🌐 ProxyRaQ

A multithreaded proxy web server built entirely in pure C, designed for performance, modularity, and scalability. Supports HTTP/HTTPS requests, caching with LRU strategy, site blocking, and high concurrency handling.

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✨ Features

• Multithreaded Proxy Server – Handles multiple client connections concurrently using a thread pool.

• Custom Fetch Utility (C-based) – Fetches remote websites without external libraries, mimicking fetch behavior.

• HTTP Parser – Minimal and custom-built parser tailored to proxy needs.

• LRU-based Cache Strategy

  • In-Memory (Linked List) for quick lookups.
  • Disk-based Storage + Persistence for large resources.
  • Cache Invalidation logic for expired/blocked entries.

• Site Blocking – Reads blocked_sites.json to deny access to restricted domains.

• SSL/TLS Support – Wraps TCP sockets with SSL for HTTPS connections.

• Dynamic Memory Allocation – Efficient fetching of large websites.

• Modular Code Structure – Each component (parsing, caching, networking, SSL, thread pool) is an independent module.

• 🐳 Dockerized for easy setup, deployment, and portability.

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🏗️ Architecture

                ┌───────────────────┐
Client Request →│ ProxyRaQ Listener │─┐
                └───────────────────┘ │
                         │             │
                         ▼             │
                 ┌───────────────┐     │
                 │ Thread Pool    │     │
                 └───────────────┘     │
                         │             │
   ┌───────────────┐  ┌──────────────┐ │
   │ HTTP Parser    │  │ Site Blocker │ │
   └───────────────┘  └──────────────┘ │
                         │             │
                         ▼             │
            ┌───────────────────────────────┐
            │ Cache (LRU + Disk Persistence) │
            └───────────────────────────────┘
                         │
                         ▼
               ┌──────────────────┐
               │ Remote Web Server │
               └──────────────────┘

• Client → ProxyRaQ → Remote Server → ProxyRaQ → Client
• Handles requests concurrently using a thread pool.
• Stores responses in LRU cache (RAM + disk) for faster future lookups.
• Filters requests if they match entries in the blocked sites list.
• Supports both HTTP & HTTPS traffic.

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📊 Benchmarks

The proxy was tested locally using ApacheBench (ab) on a 4-core CPU. We measured throughput and latency with different concurrency levels.

Clients (Concurrency)	Requests	Requests/sec	Mean Latency	Longest Request	Failures
100	10,000	~2261 req/s	~44 ms	876 ms	0
1000	10,000	~2172 req/s	~460 ms	890 ms	0

✅ Even under 1000 concurrent clients, ProxyRaQ handled all 10k requests without failure. ⚙️ Increasing backlog size from 10 → 1024 was essential to support high concurrency.

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📸 Benchmark Screenshot

(1000 concurrent clients, 10k requests, no failures)

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🔍 Observations

• Raising the socket backlog (listen(fd, backlog)) from 10 → 1024 improved stability under load.
• The proxy maintains consistent throughput (~2k req/s) even at 10× concurrency.
• Latency scales linearly with concurrency, as expected due to queuing + thread pool scheduling.
• No failed requests in either scenario, demonstrating robust handling.

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🐳 Docker Support

ProxyRaQ is fully Dockerized for easy deployment.

Build Image

docker build -t proxyraq .

Run Container

docker run -p 4040:4040 proxyraq

Now the proxy server will be running at: 👉 http://localhost:4040/?url=https://example.com

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🚀 Getting Started

1. Clone Repository

git clone https://github.com/yourusername/proxyraq.git
cd proxyraq

2. Build

make

3. Run

PORT=4040 ./server

4. Test with ApacheBench

ab -n 10000 -c 100 "http://localhost:4040/?url=https://wikipedia.org"

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📂 Project Structure

proxyraq/
├── src/
│   ├── main.c
│   ├── http_parser.c
│   ├── cache.c
│   ├── thread_pool.c
│   ├── ssl_wrapper.c
│   └── site_blocker.c
├── include/
│   ├── http_parser.h
│   ├── cache.h
│   ├── thread_pool.h
│   ├── ssl_wrapper.h
│   └── site_blocker.h
├── blocked_sites.json
├── Makefile
├── Dockerfile
└── README.md

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📌 Future Improvements

• 📊 Add monitoring & metrics dashboard.
• 🧵 Support for asynchronous I/O (epoll-based).
• 📂 Smarter cache eviction strategies.
• 🔐 Better TLS certificate management.

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👨‍💻 Author

Built with ❤️ in C by Raquib