• 微信公众号:美女很有趣。 工作之余,放松一下,关注即送10G+美女照片!

手撸golang etcd raft协议之11

互联网 diligentman 2周前 (04-06) 8次浏览

手撸golang etcd raft协议之11

缘起

最近阅读 [云原生分布式存储基石:etcd深入解析] (杜军 , 2019.1) 本系列笔记拟采用golang练习之

raft分布式一致性算法

分布式存储系统通常会通过维护多个副本来进行容错,
以提高系统的可用性。
这就引出了分布式存储系统的核心问题——如何保证多个副本的一致性?

Raft算法把问题分解成了四个子问题:
1. 领袖选举(leader election)、
2. 日志复制(log replication)、
3. 安全性(safety)
4. 成员关系变化(membership changes)
这几个子问题。

源码gitee地址:
https://gitee.com/ioly/learning.gooop

目标

  • 根据raft协议,实现高可用分布式强一致的kv存储

子目标(Day 11)

  • 虽然Leader State还有细节没处理完,但应该能启动并提供基本服务了
  • 添加外围功能,为首次“点火”做准备:
    • config/tRaftConfig:从本地json文件读取集群节点配置,提供IRaftConfig/IRaftNodeConfig的实现
    • lsm/tRaftLSMImplement: 提供对顶层接口IRaftLSM的实现,将“配置/kv存储/节点通讯”三大块粘合起来
    • server/IRaftKVServer:server启动器接口
    • server/tRaftKVServer: server启动器的实现,监听raft rpc和kv rpc

config/tRaftConfig.go

从本地json文件读取集群节点配置,提供IRaftConfig/IRaftNodeConfig的实现

package config

import (
	"encoding/json"
	"os"
)

type tRaftConfig struct {
	ID string
	Nodes []*tRaftNodeConfig
}

type tRaftNodeConfig struct {
	ID string
	Endpoint string
}

func (me *tRaftConfig) GetID() string {
	return me.ID
}

func (me *tRaftConfig) GetNodes() []IRaftNodeConfig {
	a := make([]IRaftNodeConfig, len(me.Nodes))
	for i,it := range me.Nodes {
		a[i] = it
	}
	return a
}


func (me *tRaftNodeConfig) GetID() string {
	return me.ID
}

func (me *tRaftNodeConfig) GetEndpoint() string {
	return me.Endpoint
}

func LoadJSONFile(file string) IRaftConfig {
	data, err := os.ReadFile(file)
	if err != nil {
		panic(err)
	}

	c := new(tRaftConfig)
	err = json.Unmarshal(data, c)
	if err != nil {
		panic(err)
	}

	return c
}

lsm/tRaftLSMImplement.go

提供对顶层接口IRaftLSM的实现,将“配置/kv存储/节点通讯”三大块粘合起来,并添加诊断日志。

package lsm

import (
	"learning/gooop/etcd/raft/common"
	"learning/gooop/etcd/raft/config"
	"learning/gooop/etcd/raft/logger"
	"learning/gooop/etcd/raft/rpc"
	"learning/gooop/etcd/raft/rpc/client"
	"learning/gooop/etcd/raft/store"
	"sync"
)

type tRaftLSMImplement struct {
	tEventDrivenModel
	mInitOnce sync.Once

	mConfig config.IRaftConfig
	mStore store.ILogStore
	mClientService client.IRaftClientService
	mState IRaftState
}


// trigger: init()
// args: empty
const meInit = "lsm.Init"

// trigger: HandleStateChanged()
// args: IRaftState
const meStateChanged = "lsm.StateChnaged"

func (me *tRaftLSMImplement) init() {
	me.mInitOnce.Do(func() {
		me.initEventHandlers()
		me.raise(meInit)
	})
}

func (me *tRaftLSMImplement) initEventHandlers() {
	// write only
	me.hookEventsForConfig()
	me.hookEventsForStore()
	me.hookEventsForPeerService()
	me.hookEventsForState()
}

func (me *tRaftLSMImplement) hookEventsForConfig() {
	me.hook(meInit, func(e string, args ...interface{}) {
		logger.Logf("tRaftLSMImplement.init, ConfigFile = %v", common.ConfigFile)
		me.mConfig = config.LoadJSONFile(common.ConfigFile)
	})
}

func (me *tRaftLSMImplement) hookEventsForStore() {
	me.hook(meInit, func(e string, args ...interface{}) {
		logger.Logf("tRaftLSMImplement.init, DataFile = %v", common.DataFile)
		err, db := store.NewBoltStore(common.DataFile)
		if err != nil {
			panic(err)
		}
		me.mStore = db
	})
}


func (me *tRaftLSMImplement) hookEventsForPeerService() {
	me.hook(meInit, func(e string, args ...interface{}) {
		me.mClientService = client.NewRaftClientService(me.mConfig)
	})
}

func (me *tRaftLSMImplement) hookEventsForState() {
	me.hook(meInit, func(e string, args ...interface{}) {
		me.mState = newFollowerState(me, me.mStore.LastCommittedTerm())
		me.mState.Start()
	})

	me.hook(meStateChanged, func(e string, args ...interface{}) {
		state := args[0].(IRaftState)
		logger.Logf("tRaftLSMImplement.StateChanged, %v", state.Role())

		me.mState = state
		state.Start()
	})
}


func (me *tRaftLSMImplement) Config() config.IRaftConfig {
	return me.mConfig
}

func (me *tRaftLSMImplement) Store() store.ILogStore {
	return me.mStore
}

func (me *tRaftLSMImplement) HandleStateChanged(state IRaftState) {
	me.raise(meStateChanged, state)
}

func (me *tRaftLSMImplement) RaftClientService() client.IRaftClientService {
	return me.mClientService
}

func (me *tRaftLSMImplement) Heartbeat(cmd *rpc.HeartbeatCmd, ret *rpc.HeartbeatRet) error {
	state := me.mState
	e := state.Heartbeat(cmd, ret)
	logger.Logf("tRaftLSMImplement.Heartbeat, state=%v, cmd=%v, ret=%v, err=%v", cmd, ret, e)
	return e
}

func (me *tRaftLSMImplement) AppendLog(cmd *rpc.AppendLogCmd, ret *rpc.AppendLogRet) error {
	state := me.mState
	e := state.AppendLog(cmd, ret)
	logger.Logf("tRaftLSMImplement.AppendLog, state=%v, cmd=%v, ret=%v, err=%v", cmd, ret, e)
	return e
}

func (me *tRaftLSMImplement) CommitLog(cmd *rpc.CommitLogCmd, ret *rpc.CommitLogRet) error {
	state := me.mState
	e := state.CommitLog(cmd, ret)
	logger.Logf("tRaftLSMImplement.CommitLog, state=%v, cmd=%v, ret=%v, err=%v", cmd, ret, e)
	return e
}

func (me *tRaftLSMImplement) RequestVote(cmd *rpc.RequestVoteCmd, ret *rpc.RequestVoteRet) error {
	state := me.mState
	e := state.RequestVote(cmd, ret)
	logger.Logf("tRaftLSMImplement.RequestVote, state=%v, cmd=%v, ret=%v, err=%v", cmd, ret, e)
	return e
}

func (me *tRaftLSMImplement) ExecuteKVCmd(cmd *rpc.KVCmd, ret *rpc.KVRet) error {
	state := me.mState
	e := state.ExecuteKVCmd(cmd, ret)
	logger.Logf("tRaftLSMImplement.ExecuteKVCmd, state=%v, cmd=%v, ret=%v, err=%v", cmd, ret, e)
	return e
}

func (me *tRaftLSMImplement) State() IRaftState {
	return me.mState
}

func NewRaftLSM() IRaftLSM {
	it := new(tRaftLSMImplement)
	it.init()
	return it
}

server/IRaftKVServer.go

server启动器接口

package server

type IRaftKVServer interface {
	BeginServeTCP(port int) error
}

server/tRaftKVServer.go

server启动器的实现,监听raft rpc和kv rpc

package server

import (
	"fmt"
	"learning/gooop/etcd/raft/lsm"
	rrpc "learning/gooop/etcd/raft/rpc"
	"learning/gooop/saga/mqs/logger"
	"net"
	"net/rpc"
	"time"
)

type tRaftKVServer int

func (me *tRaftKVServer) BeginServeTCP(port int) error {
	logger.Logf("tRaftKVServer.BeginServeTCP, starting, port=%v", port)

	// resolve address
	addy, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("0.0.0.0:%d", port))
	if err != nil {
		return err
	}

	// create raft lsm singleton
	raftLSM := lsm.NewRaftLSM()

	// register raft rpc server
	rserver := &RaftRPCServer {
		mRaftLSM : raftLSM,
	}
	err = rpc.Register(rserver)
	if err != nil {
		return err
	}

	// register kv rpc server
	kserver := &KVStoreRPCServer{
		mRaftLSM: raftLSM,
	}
	err = rpc.Register(kserver)
	if err != nil {
		return err
	}

	inbound, err := net.ListenTCP("tcp", addy)
	if err != nil {
		return err
	}
	go rpc.Accept(inbound)

	logger.Logf("tRaftKVServer.BeginServeTCP, service ready at port=%v", port)
	return nil
}

// RaftRPCServer exposes a raft rpc service
type RaftRPCServer struct {
	mRaftLSM lsm.IRaftLSM
}

// Heartbeat leader to follower
func (me *RaftRPCServer) Heartbeat(cmd *rrpc.HeartbeatCmd, ret *rrpc.HeartbeatRet) error {
	e := me.mRaftLSM.Heartbeat(cmd, ret)
	logger.Logf("RaftRPCServer.Heartbeat, cmd=%v, ret=%v, e=%v", cmd, ret, e)
	return e
}

// AppendLog leader to follower
func (me *RaftRPCServer) AppendLog(cmd *rrpc.AppendLogCmd, ret *rrpc.AppendLogRet) error {
	e := me.mRaftLSM.AppendLog(cmd, ret)
	logger.Logf("RaftRPCServer.AppendLog, cmd=%v, ret=%v, e=%v", cmd, ret, e)
	return e
}

// CommitLog leader to follower
func (me *RaftRPCServer) CommitLog(cmd *rrpc.CommitLogCmd, ret *rrpc.CommitLogRet) error {
	e := me.mRaftLSM.CommitLog(cmd, ret)
	logger.Logf("RaftRPCServer.CommitLog, cmd=%v, ret=%v, e=%v", cmd, ret, e)
	return e
}

// RequestVote candidate to others
func (me *RaftRPCServer) RequestVote(cmd *rrpc.RequestVoteCmd, ret *rrpc.RequestVoteRet) error {
	e := me.mRaftLSM.RequestVote(cmd, ret)
	logger.Logf("RaftRPCServer.RequestVote, cmd=%v, ret=%v, e=%v", cmd, ret, e)
	return e
}

// Ping to keep alive
func (me *RaftRPCServer) Ping(cmd *rrpc.PingCmd, ret *rrpc.PingRet) error {
	ret.SenderID = me.mRaftLSM.Config().GetID()
	ret.Timestamp = time.Now().UnixNano()

	logger.Logf("RaftRPCServer.Ping, cmd=%v, ret=%v", cmd, ret)
	return nil
}

// KVStoreRPCServer expose a kv storage service
type KVStoreRPCServer struct {
	mRaftLSM lsm.IRaftLSM
}

// ExecuteKVCmd leader to follower
func (me *KVStoreRPCServer) ExecuteKVCmd(cmd *rrpc.KVCmd, ret *rrpc.KVRet) error {
	e := me.mRaftLSM.ExecuteKVCmd(cmd, ret)
	logger.Logf("KVStoreRPCServer.ExecuteKVCmd, cmd=%v, ret=%v, e=%v", cmd, ret, e)
	return e
}

(未完待续)

展开阅读全文

goheartbeat

© 著作权归作者所有

举报

打赏

0


0 收藏

微信
QQ
微博

分享

作者的其它热门文章

手撸golang 基本数据结构与算法 图的最短路径 A*(A-Star)算法
手撸golang 行为型设计模式 责任链模式
手撸golang 基本数据结构与算法 网页排名/PageRank,随机游走
手撸golang 基本数据结构与算法 哈希表


程序员灯塔
转载请注明原文链接:手撸golang etcd raft协议之11
喜欢 (0)