tokio-rs/mini-redis

This repository contains an intentionally incomplete version of Redis built in the Rust programming language. Redis is a widely used tool that stores data in memory for fast retrieval, often used to speed up web applications by caching frequently requested information. This project is not meant to replace Redis or to be used in real applications. It exists purely as a teaching example for developers learning Tokio, which is Rust's main library for writing software that handles many tasks at the same time without blocking. The project builds a working server and a client library that speak a simplified version of the Redis communication format. It supports only five commands out of the hundreds Redis offers: PING (to check if the server is alive), GET and SET (to read and write key-value data), and PUBLISH and SUBSCRIBE (to send and receive messages between connected clients). There is no data storage on disk, so everything disappears when the server stops. The value of the project is not the Redis functionality itself but the patterns it demonstrates. The code shows how to write a TCP server that handles many simultaneous connections, how to share data safely between those connections, how to shut down gracefully when interrupted, how to limit the number of connections running at once, and how to implement a publish-subscribe messaging system. Each of these is a common challenge in networked software, and the codebase is heavily commented to explain the choices involved. The README is explicit that contributors should only add new features if doing so illustrates a pattern that is not already covered. The project is maintained by the Tokio team as a companion to their documentation and tutorials. If you need a Redis client for actual use, this is not it, and the README says so directly.