fix `error: concurrent map writes` when add or remove cluster node

weed/cluster/cluster.go

@@ -46,8 +46,6 @@ func NewCluster() *Cluster {
 }
 
 func (cluster *Cluster) getFilers(filerGroup FilerGroup, createIfNotFound bool) *Filers {
-	cluster.filersLock.Lock()
-	defer cluster.filersLock.Unlock()
 	filers, found := cluster.filerGroup2filers[filerGroup]
 	if !found && createIfNotFound {
 		filers = &Filers{
@@ -63,6 +61,8 @@ func (cluster *Cluster) AddClusterNode(ns, nodeType string, address pb.ServerAdd
 	filerGroup := FilerGroup(ns)
 	switch nodeType {
 	case FilerType:
+		cluster.filersLock.Lock()
+		defer cluster.filersLock.Unlock()
 		filers := cluster.getFilers(filerGroup, true)
 		if existingNode, found := filers.filers[address]; found {
 			existingNode.counter++
@@ -115,6 +115,8 @@ func (cluster *Cluster) RemoveClusterNode(ns string, nodeType string, address pb
 	filerGroup := FilerGroup(ns)
 	switch nodeType {
 	case FilerType:
+		cluster.filersLock.Lock()
+		defer cluster.filersLock.Unlock()
 		filers := cluster.getFilers(filerGroup, false)
 		if filers == nil {
 			return nil
@@ -165,12 +167,12 @@ func (cluster *Cluster) RemoveClusterNode(ns string, nodeType string, address pb
 func (cluster *Cluster) ListClusterNode(filerGroup FilerGroup, nodeType string) (nodes []*ClusterNode) {
 	switch nodeType {
 	case FilerType:
+		cluster.filersLock.RLock()
+		defer cluster.filersLock.RUnlock()
 		filers := cluster.getFilers(filerGroup, false)
 		if filers == nil {
 			return
 		}
-		cluster.filersLock.RLock()
-		defer cluster.filersLock.RUnlock()
 		for _, node := range filers.filers {
 			nodes = append(nodes, node)
 		}

weed/cluster/cluster_test.go

@@ -3,6 +3,8 @@ package cluster
 import (
 	"github.com/chrislusf/seaweedfs/weed/pb"
 	"github.com/stretchr/testify/assert"
+	"strconv"
+	"sync"
 	"testing"
 )
 
@@ -45,3 +47,35 @@ func TestClusterAddRemoveNodes(t *testing.T) {
 	c.RemoveClusterNode("", "filer", pb.ServerAddress("111:1"))
 
 }
+
+func TestConcurrentAddRemoveNodes(t *testing.T) {
+	c := NewCluster()
+	var wg sync.WaitGroup
+	for i := 0; i < 50; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			address := strconv.Itoa(i)
+			c.AddClusterNode("", "filer", pb.ServerAddress(address), "23.45")
+		}(i)
+	}
+	wg.Wait()
+
+	for i := 0; i < 50; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			address := strconv.Itoa(i)
+			node := c.RemoveClusterNode("", "filer", pb.ServerAddress(address))
+
+			if len(node) == 0 {
+				t.Errorf("TestConcurrentAddRemoveNodes: node[%s] not found", address)
+				return
+			} else if node[0].ClusterNodeUpdate.Address != address {
+				t.Errorf("TestConcurrentAddRemoveNodes: expect:%s, actual:%s", address, node[0].ClusterNodeUpdate.Address)
+				return
+			}
+		}(i)
+	}
+	wg.Wait()
+}