Redis Clone in Rust

A lightweight Redis-inspired in-memory database built from scratch in Rust using Tokio and the RESP protocol.

This project implements a multithreaded TCP server capable of handling multiple concurrent clients while supporting core Redis-like commands such as SET, GET, DEL, TTL, DBSIZE, and FLUSHALL.

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Features

Networking

• TCP server using Tokio
• Concurrent client handling
• Async socket communication
• Non-blocking I/O

RESP Protocol Support

• Simple Strings
• Errors
• Integers
• Bulk Strings
• Arrays
• Null values

Redis-like Commands

• PING
• SET
• GET
• DEL
• TTL
• DBSIZE
• FLUSHALL

Key Expiration

• EX support (seconds)
• PX support (milliseconds)
• Automatic cleanup of expired keys

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Architecture

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Tech Stack

Technology	Purpose
Rust	Systems programming language
Tokio	Async runtime
Bytes	Efficient byte storage
TCP Sockets	Client-server communication

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Project Structure

src/
│
├── main.rs         # Entry point
├── resp.rs         # RESP data types + serialization
├── parser.rs       # RESP protocol parser
├── store.rs        # In-memory database
├── commands.rs     # Command handling logic
└── client.rs       # TCP client handling

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How It Works

1. TCP Server

The server listens on:

127.0.0.1:6379

Whenever a new client connects:

• A new async Tokio task is spawned
• Each client gets handled independently
• Multiple clients can interact simultaneously

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2. RESP Protocol Parsing

Redis uses RESP (Redis Serialization Protocol).

Example request:

*2
$4
PING
$4
PONG

The parser:

• Reads raw TCP bytes
• Detects RESP data types
• Converts them into Rust enums

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3. In-Memory Database

Data is stored using:

HashMap<Bytes, ValueWithExpiry>

Wrapped inside:

Arc<Mutex<_>>

This allows:

• Shared ownership
• Thread safety
• Concurrent access

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Installation

Clone Repository

git clone https://github.com/yourusername/redis-clone-rust.git
cd redis-clone-rust

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Build Project

cargo build

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Run Server

cargo run

Server output:

Redis clone listening on 127.0.0.1:6379
Ready to accept connections!

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Testing With redis-cli

Connect using:

redis-cli -p 6379

Example session:

127.0.0.1:6379> PING
PONG

127.0.0.1:6379> SET name anirudh
OK

127.0.0.1:6379> GET name
"anirudh"

127.0.0.1:6379> DBSIZE
(integer) 1

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Example RESP Serialization

Rust Enum

RespValue::SimpleString("OK".to_string())

Serialized Output

+OK\r\n

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Concurrency Model

This project uses:

tokio::spawn()

to handle clients concurrently.

Each connection:

• Runs independently
• Shares the same database
• Uses thread-safe synchronization

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Key Rust Concepts Used

• Ownership & Borrowing
• Arc
• Mutex
• Async/Await
• Enums
• Pattern Matching
• TCP Networking
• Shared State Management

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Author

Anirudh Patwal

GitHub: https://github.com/yourusername

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License

This project is licensed under the MIT License.