Go-Redis

Go-Redis is a high-performance, single-threaded, Redis-compatible Key-Value store implemented in Go. It replicates the core architecture of Redis to achieve high throughput and low latency, handling ~49,000 GET/sec at 20 µs average latency on a single thread.

This project was built to explore operating system internals, specifically non-blocking I/O, event loops, and efficient data structures.

🚀 Key Features

• I/O Multiplexing: Implements a custom event loop using syscall.EpollWait (Linux) and syscall.Kqueue (macOS) to handle thousands of concurrent connections (C10k ready).
• Redis Protocol (RESP): 100% compatible with existing Redis clients (redis-cli, Jedis, go-redis).
• Data Structures:
  • Strings: Binary-safe string storage.
  • Hash Maps: Incremental resizing for strict $O(1)$ performance.
  • Sorted Sets (ZSET): Implementation of SkipList for $O(\log N)$ range queries and ranking.
• Persistence: AOF (Append Only File) persistence (optional configuration).
• TTL: Key expiration and eviction strategies (LRU approximation).

⚡ Performance

Benchmarks conducted on a local development environment (Intel Core i7-10750H) demonstrate performance comparable to standard Redis for supported commands.

Metric	Throughput	Latency (Avg)
GET	~49,000 ops/sec	20 µs
SET	~44,500 ops/sec	22 µs

Verified using redis-benchmark -t set,get -n 100000 -c 50 — 50 concurrent connections, average latency per operation.

Load testing — a different measurement

The 20 µs above is redis-benchmark average latency at 50 connections. Under a sustained load test at 200+ virtual users the server stays up and P95 rises to ~129 ms: a saturation figure, not a per-operation one. The two numbers describe different loads and are not comparable — quote whichever matches the question.

🛠 Architecture

The architecture mimics the single-threaded event loop design of Redis:

graph TD
    Client1[Client] -->|TCP IP| Epoll["Event Loop (Epoll/Kqueue)"]
    Client2[Client] -->|TCP IP| Epoll
    
    Epoll -->|File Event| FileHandler[Connection Handler]
    Timer["Time Events"] -->|Tick| TimerHandler["Cron/Cleanup"]
    
    FileHandler --> Parser["RESP Parser"]
    Parser --> Dispatcher["Command Dispatcher"]
    
    Dispatcher --> Dict["Global Dictionary (Hash Map)"]
    Dispatcher --> SkipList["Sorted Set Engine"]
    
    subgraph "Core Engine (Single Threaded)"
        Epoll
        FileHandler
        Parser
        Dispatcher
    end

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📦 Getting Started

Prerequisites

• Go 1.21+
• Docker (optional)

Building Locally

# Clone the repository
git clone https://github.com/Mazukiri/Go-Redis.git
cd Go-Redis

# Build the binary
make build

# Run the server
make run

The server listens on 0.0.0.0:8082 by default.

Running with Docker

docker build -t redis-clone .
docker run -p 8082:8082 -p 9090:9090 redis-clone

🧪 Testing

# Run unit tests
make test

# Run benchmarks
make bench

🤝 Usage with Redis CLI

You can connect using the standard redis-cli:

redis-cli -p 8082
127.0.0.1:8082> SET mykey "Hello World"
OK
127.0.0.1:8082> GET mykey
"Hello World"

📄 License

MIT