mjraft

Java implementation of the raft protocol as described by the paper https://raft.github.io/raft.pdf

Supported features

• Log replication
• Leader election
• Client API to submit log entries
• Embeddable into your distributed application
• Redirect to leader from follower/candidate
• Consistency check

Usage

Building the code

mvn clean install

Command line cluster

Start a new cluster by starting a server listening on port 5001

java -cp target/mjraft-1.0-SNAPSHOT.jar com.mj.distributed.peertopeer.server.PeerServer 5001

Add a second server listening on port 5002 which connects to the first

java -cp target/mjraft-1.0-SNAPSHOT.jar com.mj.distributed.peertopeer.server.PeerServer 5002 localhost:5001

Add a third server listening on port 5003 which connects to the first

java -cp target/mjraft-1.0-SNAPSHOT.jar com.mj.distributed.peertopeer.server.PeerServer 5003 localhost:5001

Use RaftClient to connect to any server and send values to be replicated

java -cp target/mjraft-1.0-SNAPSHOT.jar com.mj.raft.client.RaftClient localhost 5001

Embedded

Start a new cluster by starting a server

PeerServer leader = new PeerServer(5001);
leader.start() ;

Add additional servers to the cluster

String[] seeds = new String[1];
seeds[0] = "localhost:5001"; // can connect to any server

PeerServer server1 = new PeerServer(5002, seeds);
server1.start();

PeerServer server2 = new PeerServer(5003, seeds);
server2.start();

Client api

Send log entries to the leader

RaftClient raftClient = new RaftClient("localhost", 5001); // can connect to any server
raftClient.connect();
raftClient.send(23);

Get log entries from leader

List<byte[]> serverValues = raftClient.get(0,1);