raft

Package raft implements the Raft distributed consensus protocol.

Features

• Leader Election
• Log Replication
• Membership Changes
• Log Compaction (Snapshotting)
• RPC transport
• WAL
• ReadIndex/Lease Read
• Non-Voting Members (The leader only replicates log entries to them)
• Snapshot Policies (Never/EverySecond/CustomSync/Always)

Get started

Install

go get github.com/hslam/raft

Import

import "github.com/hslam/raft"

HelloWorld

• Leader Election
• Non-Voting Members
• Membership Changes

helloworld.go

package main

import (
	"flag"
	"fmt"
	"github.com/hslam/raft"
	"strings"
	"time"
)

var (
	host  string
	port  int
	path  string
	join  bool
	peers string
)

func init() {
	flag.StringVar(&host, "h", "localhost", "hostname")
	flag.IntVar(&port, "p", 9001, "port")
	flag.StringVar(&path, "path", "raft.helloworld/node.1", "data dir")
	flag.BoolVar(&join, "join", false, "")
	flag.StringVar(&peers, "peers", "localhost:9001,false;", "host:port,nonVoting;host:port,nonVoting;")
}
func main() {
	flag.Parse()
	raft.SetLogLevel(raft.DebugLevel)
	var nodes []string
	var infos []*raft.NodeInfo
	if peers != "" {
		nodes = strings.Split(peers, ";")
		for _, v := range nodes {
			if v == "" {
				continue
			}
			info := strings.Split(v, ",")
			var NonVoting bool
			if len(info) > 1 {
				if info[1] == "true" {
					NonVoting = true
				}
			}
			infos = append(infos, &raft.NodeInfo{Address: info[0], NonVoting: NonVoting, Data: nil})
		}
	}
	node, err := raft.NewNode(host, port, path, nil, join, infos)
	if err != nil {
		panic(err)
	}
	node.Start()
	for {
		fmt.Printf("%d State:%s - Leader:%s\n", time.Now().Unix(), node.State(), node.Leader())
		time.Sleep(time.Second * 3)
	}
}

one node

./node -h=localhost -p=9001 -path="raft.helloworld/node.1" -join=false -peers="localhost:9001"

three nodes

./node -h=localhost -p=9001 -path="raft.helloworld/node.hw.1" -join=false -peers="localhost:9001;localhost:9002;localhost:9003"
./node -h=localhost -p=9002 -path="raft.helloworld/node.hw.2" -join=false -peers="localhost:9001;localhost:9002;localhost:9003"
./node -h=localhost -p=9003 -path="raft.helloworld/node.hw.3" -join=false -peers="localhost:9001;localhost:9002;localhost:9003"

non-voting

./node -h=localhost -p=9001 -path="raft.helloworld/node.nv.1" -join=false -peers="localhost:9001;localhost:9002;localhost:9003;localhost:9004,true"
./node -h=localhost -p=9002 -path="raft.helloworld/node.nv.2" -join=false -peers="localhost:9001;localhost:9002;localhost:9003;localhost:9004,true"
./node -h=localhost -p=9003 -path="raft.helloworld/node.nv.3" -join=false -peers="localhost:9001;localhost:9002;localhost:9003;localhost:9004,true"
./node -h=localhost -p=9004 -path="raft.helloworld/node.nv.4" -join=false -peers="localhost:9001;localhost:9002;localhost:9003;localhost:9004,true"

membership changes

./node -h=localhost -p=9001 -path="raft.helloworld/node.mc.1" -join=false
./node -h=localhost -p=9002 -path="raft.helloworld/node.mc.2" -join=true -peers="localhost:9001;localhost:9002"
./node -h=localhost -p=9003 -path="raft.helloworld/node.mc.3" -join=true -peers="localhost:9001;localhost:9002;localhost:9003"

Example

• Leader Election
• Non-Voting Members
• Membership Changes
• Log Replication
• Log Compaction (Snapshotting)
• ReadIndex/Lease Read
• Snapshot Policies
• Benchmark

one node set

./example -h=localhost -p=9001 -path="raft.example/node.1" -join=false -peers="localhost:9001" -log=true -b=true  -o=set -parallel=4096 -total=100000

one node readindex

./example -h=localhost -p=9001 -path="raft.example/node.1" -join=false -peers="localhost:9001" -log=true -b=true  -o=readindex -parallel=4096 -total=100000

one node lease

./example -h=localhost -p=9001 -path="raft.example/node.1" -join=false -peers="localhost:9001" -log=true -b=true  -o=lease -parallel=4096 -total=100000

three nodes set

./example -h=localhost -p=9001 -path="raft.example/node.tn.1" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=set -parallel=4096 -total=100000
./example -h=localhost -p=9002 -path="raft.example/node.tn.2" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=set -parallel=4096 -total=100000
./example -h=localhost -p=9003 -path="raft.example/node.tn.3" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=set -parallel=4096 -total=100000

three nodes readindex

./example -h=localhost -p=9001 -path="raft.example/node.tn.1" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=readindex -parallel=4096 -total=100000
./example -h=localhost -p=9002 -path="raft.example/node.tn.2" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=readindex -parallel=4096 -total=100000
./example -h=localhost -p=9003 -path="raft.example/node.tn.3" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=readindex -parallel=4096 -total=100000

three nodes lease

./example -h=localhost -p=9001 -path="raft.example/node.tn.1" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=lease -parallel=4096 -total=100000
./example -h=localhost -p=9002 -path="raft.example/node.tn.2" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=lease -parallel=4096 -total=100000
./example -h=localhost -p=9003 -path="raft.example/node.tn.3" -join=false -peers="localhost:9001;localhost:9002;localhost:9003" -log=true -b=true    -o=lease -parallel=4096 -total=100000

RaftDB

The raftdb is an example usage of raft library.

Linux Environment

• CPU 12 Cores 3.1 GHz
• Memory 24 GiB

Benchmark

cluster    operation transport requests/s average fastest median  p99      slowest
Singleton  ReadIndex HTTP      73348      6.77ms  2.59ms  6.29ms  14.23ms  116.32ms
Singleton  Write     HTTP      60671      8.27ms  2.47ms  7.34ms  23.08ms  134.83ms
ThreeNodes ReadIndex HTTP      54642      9.31ms  2.97ms  7.85ms  69.98ms  106.80ms
ThreeNodes Write     HTTP      37647      13.39ms 4.62ms  9.61ms  77.57ms  142.90ms
Singleton  ReadIndex RPC       310222     12.51ms 4.36ms  12.07ms 29.79ms  34.28ms
Singleton  Write     RPC       138411     28.92ms 6.09ms  24.64ms 103.57ms 121.66ms
ThreeNodes ReadIndex RPC       285650     13.40ms 4.27ms  12.49ms 29.01ms  32.91ms
ThreeNodes Write     RPC       118325     33.74ms 9.76ms  33.40ms 71.38ms  81.32ms

License

This package is licensed under a MIT license (Copyright (c) 2019 Meng Huang)

Author

raft was written by Meng Huang.