封装了rpc超时，修复并发candidate时的异常

internal/client/client_node.go

@@ -42,10 +42,11 @@ func (client *Client) FindActiveNode() *rpc.Client {
 	var c *rpc.Client
 	for  { // 直到找到一个可连接的节点（保证至少一个节点活着）
 		addr := getRandomAddress(client.Address)
-		c, err = rpc.DialHTTP("tcp", addr)
+		c, err = nodes.DialHTTPWithTimeout("tcp", addr)
 		if err != nil {
 			log.Error("dialing: ", zap.Error(err))
 		} else {
+			log.Sugar().Info("client发现活跃节点地址[%s]", addr)
 			return c
 		}
 	}
@@ -67,7 +68,7 @@ func (client *Client) Write(kvCall nodes.LogEntryCall) Status {
 	var err error
 
 	for !reply.Isleader { // 根据存活节点的反馈，直到找到leader
-		callErr := c.Call("Node.WriteKV", kvCall, &reply) // RPC
+		callErr := nodes.CallWithTimeout(c, "Node.WriteKV", &kvCall, &reply) // RPC
 		if callErr != nil { // dial和call之间可能崩溃，重新找存活节点
 			log.Error("dialing: ", zap.Error(callErr))
 			client.CloseRpcClient(c)
@@ -78,7 +79,7 @@ func (client *Client) Write(kvCall nodes.LogEntryCall) Status {
 		if !reply.Isleader { // 对方不是leader，根据反馈找leader
 			addr := reply.LeaderAddress
 			client.CloseRpcClient(c)
-			c, err = rpc.DialHTTP("tcp", addr)
+			c, err = nodes.DialHTTPWithTimeout("tcp", addr)
 			for err != nil { // 重新找下一个存活节点
 				c = client.FindActiveNode()
 			}
@@ -101,7 +102,7 @@ func (client *Client) Read(key string, value *string) Status { // 查不到value
 		c = client.FindActiveNode()
 
 		var reply nodes.ServerReply
-		callErr := c.Call("Node.ReadKey", key, &reply) // RPC
+		callErr := nodes.CallWithTimeout(c, "Node.ReadKey", &key, &reply) // RPC
 		if callErr != nil {
 			log.Error("dialing: ", zap.Error(callErr))
 			client.CloseRpcClient(c)
@@ -128,7 +129,7 @@ func (client *Client) FindLeader() string {
 	var err error
 
 	for !reply.Isleader { // 根据存活节点的反馈，直到找到leader
-		callErr := c.Call("Node.FindLeader", &arg, &reply) // RPC
+		callErr := nodes.CallWithTimeout(c, "Node.FindLeader", &arg, &reply) // RPC
 		if callErr != nil { // dial和call之间可能崩溃，重新找存活节点
 			log.Error("dialing: ", zap.Error(callErr))
 			client.CloseRpcClient(c)
@@ -139,7 +140,7 @@ func (client *Client) FindLeader() string {
 		if !reply.Isleader { // 对方不是leader，根据反馈找leader
 			addr := client.Address[reply.LeaderId]
 			client.CloseRpcClient(c)
-			c, err = rpc.DialHTTP("tcp", addr)
+			c, err = nodes.DialHTTPWithTimeout("tcp", addr)
 			for err != nil { // 重新找下一个存活节点
 				c = client.FindActiveNode()
 			}

internal/nodes/init.go

@@ -1,6 +1,7 @@
 package nodes
 
 import (
+	// "context"
 	"fmt"
 	"net"
 	"net/http"
@@ -30,7 +31,7 @@ func Init(selfId string, nodeAddr map[string]string, db *leveldb.DB, rstorage *R
 	// 创建节点
 	node := &Node{
 		selfId:      selfId,
-		leaderId: 	 "",
+		leaderId:    "",
 		nodes:       ns,
 		maxLogId:    -1, // 后来发现论文中是从1开始的（初始0），但不想改了
 		currTerm:    1,
@@ -40,7 +41,7 @@ func Init(selfId string, nodeAddr map[string]string, db *leveldb.DB, rstorage *R
 		nextIndex:   make(map[string]int),
 		matchIndex:  make(map[string]int),
 		db:          db,
-		storage: rstorage,
+		storage:     rstorage,
 	}
 	node.initLeaderState()
 	if isRestart {
@@ -74,6 +75,7 @@ func Start(node *Node) {
 			case Leader:
 				// 发送心跳
 				fmt.Printf("[%s] is the leader, 发送心跳...\n", node.selfId)
+				node.resetElectionTimer() // leader不主动触发选举
 				node.BroadCastKV(Normal)
 			}
 			time.Sleep(50 * time.Millisecond)
@@ -81,7 +83,9 @@ func Start(node *Node) {
 	}()
 }
 
+// 初始时注册rpc方法
 func (node *Node) Rpc(port string) {
+
 	err := rpc.Register(node)
 	if err != nil {
 		log.Fatal("rpc register failed", zap.Error(err))
@@ -99,3 +103,38 @@ func (node *Node) Rpc(port string) {
 		}
 	}()
 }
+
+// 封装有超时的dial
+func DialHTTPWithTimeout(network, address string) (*rpc.Client, error) {
+	done := make(chan struct{})
+	var client *rpc.Client
+	var err error
+
+	go func() {
+		client, err = rpc.DialHTTP(network, address)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+		return client, err
+	case <-time.After(50 * time.Millisecond):
+		return nil, fmt.Errorf("dial timeout: %s", address)
+	}
+}
+
+// 封装有超时的call
+func CallWithTimeout[T1 any, T2 any](client *rpc.Client, serviceMethod string, args *T1, reply *T2) error {
+	done := make(chan error, 1)
+
+	go func() {
+		done <- client.Call(serviceMethod, args, reply)
+	}()
+
+	select {
+	case err := <-done:
+		return err
+	case <-time.After(50 * time.Millisecond):
+		return fmt.Errorf("call timeout: %s", serviceMethod)
+	}
+}

internal/nodes/replica.go

@@ -47,7 +47,7 @@ func (node *Node) sendKV(id string, callMode CallMode) {
 	default:
 	}
 
-	client, err := rpc.DialHTTP("tcp", node.nodes[id].address)
+	client, err := DialHTTPWithTimeout("tcp", node.nodes[id].address)
 	if err != nil {
 		log.Error("dialing: ", zap.Error(err))
 		return
@@ -82,7 +82,7 @@ func (node *Node) sendKV(id string, callMode CallMode) {
 		if arg.PrevLogIndex >= 0 {
 			arg.PrevLogTerm = node.log[arg.PrevLogIndex].Term
 		}
-		callErr := client.Call("Node.AppendEntries", arg, &appendReply) // RPC
+		callErr := CallWithTimeout(client, "Node.AppendEntries", &arg, &appendReply) // RPC
 		if callErr != nil {
 			log.Error("dialing node_"+ id +"fail: ", zap.Error(callErr))
 		}
@@ -142,7 +142,11 @@ func (node *Node) applyCommittedLogs() {
 }
 
 // RPC call
-func (node *Node) AppendEntries(arg AppendEntriesArg, reply *AppendEntriesReply) error {
+func (node *Node) AppendEntries(arg *AppendEntriesArg, reply *AppendEntriesReply) error {
+	// start := time.Now()
+	// defer func() {
+	// 	log.Sugar().Infof("AppendEntries 处理时间: %v", time.Since(start))
+	// }()
     node.mu.Lock()
     defer node.mu.Unlock()
 

internal/nodes/server_node.go

@@ -14,7 +14,7 @@ type ServerReply struct{
 	Value string
 }
 // RPC call
-func (node *Node) WriteKV(kvCall LogEntryCall, reply *ServerReply) error {
+func (node *Node) WriteKV(kvCall *LogEntryCall, reply *ServerReply) error {
 	log.Sugar().Infof("[%s]收到客户端write请求", node.selfId)
 
 	// 自己不是leader，转交leader地址回复	
@@ -43,10 +43,10 @@ func (node *Node) WriteKV(kvCall LogEntryCall, reply *ServerReply) error {
 }
 
 // RPC call
-func (node *Node) ReadKey(key string, reply *ServerReply) error {
+func (node *Node) ReadKey(key *string, reply *ServerReply) error {
 	log.Sugar().Infof("[%s]收到客户端read请求", node.selfId)
 	// 先只读自己(无论自己是不是leader)，也方便测试
-	value, err := node.db.Get([]byte(key), nil)
+	value, err := node.db.Get([]byte(*key), nil)
 	if err == leveldb.ErrNotFound {
 		reply.HaveValue = false
 	} else {

internal/nodes/vote.go

@@ -56,7 +56,6 @@ func (n *Node) startElection() {
 
     // 并行向其他节点发送请求投票
     var mu sync.Mutex
-    cond := sync.NewCond(&mu)
     totalNodes := len(n.nodes)
     grantedVotes := 1 // 自己的票
 
@@ -86,7 +85,6 @@ func (n *Node) startElection() {
 					n.state = Leader
 					log.Sugar().Infof("[%s] 当选 Leader!", n.selfId)
 					n.initLeaderState()
-					cond.Broadcast()
 				}
 	
 				mu.Unlock()
@@ -95,31 +93,19 @@ func (n *Node) startElection() {
 	}
 	
 	// 等待选举结果
-	timeout := time.After(300 * time.Millisecond)
-	
-	for {
-		mu.Lock()
-		if n.state != Candidate { // 选举成功或回退，不再等待
-			mu.Unlock()
-			return
-		}
-		select {
-		case <-timeout:
-			log.Sugar().Infof("[%s] 选举超时，重新发起选举", n.selfId)
-			n.state = Follower
-			n.resetElectionTimer()
-			mu.Unlock()
-			return
-		default:
-			cond.Wait()
-		}
-		mu.Unlock()
+	time.Sleep(300 * time.Millisecond)
+	mu.Lock()
+	if n.state == Candidate {
+		log.Sugar().Infof("[%s] 选举超时，重新发起选举", n.selfId)
+		// n.state = Follower 这里不修改，如果appendentries收到term合理的心跳，再变回follower
+		n.resetElectionTimer()
 	}
+	mu.Unlock()
 }
 
 func (node *Node) sendRequestVote(peerId string, args *RequestVoteArgs, reply *RequestVoteReply) bool {
 	log.Sugar().Infof("[%s] 请求 [%s] 投票给自己", node.selfId, peerId)
-	client, err := rpc.DialHTTP("tcp", node.nodes[peerId].address)
+	client, err := DialHTTPWithTimeout("tcp", node.nodes[peerId].address)
 	if err != nil {
 		log.Error("dialing: ", zap.Error(err))
 		return false
@@ -132,7 +118,7 @@ func (node *Node) sendRequestVote(peerId string, args *RequestVoteArgs, reply *R
 		}
 	}(client)
 
-	callErr := client.Call("Node.RequestVote", args, reply) // RPC
+	callErr := CallWithTimeout(client, "Node.RequestVote", args, reply) // RPC
 	if callErr != nil {
 		log.Error("dialing node_"+peerId+"fail: ", zap.Error(callErr))
 	}