README.md

Goelect is an open-source Go (Golang) library for leader election. It is heavily influenced by the election component of the Raft implementation. For more details, you can refer to Raft Wiki.

Features

• Independent Operation: No third-party services are required. You don't need to set up or rely on external systems like ZooKeeper or etcd.
• Simplified Integration: Easy to integrate into your existing Golang projects with minimal configuration.
• Supports Novote role：The no-vote node does not participate in the election.
• Highly Available: Built to be fault-tolerant, suitable for systems that require high availability.

How to use

Config

// ElectConfig is a struct that represents the configuration for an election.
type ElectConfig struct {
    // Timeout for heartbeat messages, in milliseconds
    HeartBeatInterval uint
    // Timeout for election messages, in milliseconds
    ElectTimeout uint
    // Timeout for connecting to peers, in seconds
    ConnectTimeout uint
    // List of peers in the network
    Peers []Node
    // Node represents the information of this node
    Node Node
    // State callbacks
    CallBacks *StateCallBacks
    // Timeout for callbacks, in seconds
    CallBackTimeout int
}

Example

examples/onenode/node.go is a great example of using this goelect package.

Create an Elect instance:

 // use the built-in RPC as the transport layer. 
 rpcTransport, err := rpc.NewRPC(logger)
 if err != nil {
  return nil, err
 }
 e, err := goelect.NewElect(
    rpcTransport,
    // rpc transport config
    &rpc.Config{},
    &goelect.ElectConfig{
        ElectTimeout:      200,
        HeartBeatInterval: 150,
        ConnectTimeout:    10,
        Peers:             peerNodes,
        // state transition callbacks
        CallBacks: &goelect.StateCallBacks{
            EnterLeader:    enterLeader,
            LeaveLeader:    leaveLeader,
            EnterFollower:  enterFollower,
            LeaveFollower:  leaveFollower, 
            EnterCandidate: enterCandidate,
            LeaveCandidate: leaveCandidate,
        },
        // self node
        Node: goelect.Node{
            Address: *nodeAddress,
            ID:      *nodeAddress,
        },
    }, logger)

Start the Elect:

err = e.Run()

This is everything we need to do :)