Raft Lite

Raft Lite is a very simple and understandable implementation of the Raft consensus algorithm. It is intended to be used as a learning tool for those who are interested in understanding how Raft works internally.

The algorithm is implemented in a event-driven way, which is different from the original paper. The idea is borrowed from my master supervisor Martin Kleppmann's course "Distributed Systems".

Usage

Add this to your Cargo.toml:

[dependencies]
raft-lite = "0.1.0"

To use it in your project, you can initialize a Raft instance with a RaftConfig. The way you interact with the Raft instance is to send messages to it and receive messages from it. The message type is Vec<u8>. The Raft protocol will guarantee the message delivery is in total order. The following example shows how to use it:

use raft_lite::config::{RaftConfig, RaftParams};
use raft_lite::persister::AsyncFilePersister;
use raft_lite::raft::Raft;

#[tokio::main]
async fn main() {
    let config = RaftConfig::new(
        vec!["localhost:8080".to_string(), "localhost:8081".to_string()],
        "localhost:8080".to_string(),
        RaftParams::default(),
        Box::new(AsyncFilePersister::default()),
    );
    let mut raft = Raft::new(config);
    let (mtx, mut mrx) = tokio::sync::mpsc::channel::<Vec<u8>>(100);
    let (btx, brx) = tokio::sync::mpsc::channel::<Vec<u8>>(100);
    raft.run(brx, mtx);
    // broadcast message to raft
    btx.send("hello".to_string().into_bytes()).await.unwrap();
    loop {
        // receive message from application
        let message = mrx.recv().await.unwrap();
        println!("Received message from application: {:?}", message);
    }
}

License

The project is under MIT license.

Related Projects

TODO