6.5840 Lab-Key/Value Server 思路

湫qiu2024-12-21 16:07

6.824 Lab 2: Key/Value Server

在本实验中，需要构建一个键/值服务器，以确保每个操作在网络故障 的情况下都只执行一次，并且操作是线性化的。

网络故障

示例代码

Go 复制代码

type Clerk struct {
	server   *labrpc.ClientEnd
	workerId int64
	seq      int64
}

Go 复制代码

func (ck *Clerk) PutAppend(key string, value string, op string) string {
	reply := new(PutAppendReply)
	for !reply.Ok {
		ck.server.Call("KVServer."+op, &PutAppendArgs{key, value, ck.workerId, ck.seq}, reply)
	}
	ck.seq++
	v := reply.Value
	reply.Ok = false
	return v
}

Go 复制代码

type KVServer struct {
	mu sync.RWMutex

	m      map[string]string
	seqSet map[string]string
}

Go 复制代码

func (kv *KVServer) Append(args *PutAppendArgs, reply *PutAppendReply) {
	kv.mu.Lock()
	defer kv.mu.Unlock()
	
	key := strconv.Itoa(int(args.WorkerId)) + strconv.Itoa(int(args.Seq))
	//检查是不是执行过
	if v, ok := kv.seqSet[key]; ok {
		reply.Ok = true
		reply.Value = v
		return
	}
	//删除上一次的缓存
	delete(kv.seqSet, strconv.Itoa(int(args.WorkerId))+strconv.Itoa(int(args.Seq-1)))
	//执行Append
	s := kv.m[args.Key]
	kv.seqSet[key] = s
	kv.m[args.Key] = s + args.Value
	reply.Value = s
	reply.Ok = true
}

tips

测试文件运行在linux下比windows快不少，建议在linux测试