diff --git a/weed/cluster/cluster.go b/weed/cluster/cluster.go
index 2e753812c..52d32f697 100644
--- a/weed/cluster/cluster.go
+++ b/weed/cluster/cluster.go
@@ -44,9 +44,7 @@ func newClusterNodeGroups() *ClusterNodeGroups {
 func (g *ClusterNodeGroups) getGroupMembers(filerGroup FilerGroupName, createIfNotFound bool) *GroupMembers {
 	members, found := g.groupMembers[filerGroup]
 	if !found && createIfNotFound {
-		members = &GroupMembers{
-			members: make(map[pb.ServerAddress]*ClusterNode),
-		}
+		members = newGroupMembers()
 		g.groupMembers[filerGroup] = members
 	}
 	return members
diff --git a/weed/cluster/group_members.go b/weed/cluster/group_members.go
index 01b97feae..79bd78790 100644
--- a/weed/cluster/group_members.go
+++ b/weed/cluster/group_members.go
@@ -9,6 +9,12 @@ type GroupMembers struct {
 	members map[pb.ServerAddress]*ClusterNode
 }
 
+func newGroupMembers() *GroupMembers {
+	return &GroupMembers{
+		members: make(map[pb.ServerAddress]*ClusterNode),
+	}
+}
+
 func (m *GroupMembers) addMember(dataCenter DataCenter, rack Rack, address pb.ServerAddress, version string) *ClusterNode {
 	if existingNode, found := m.members[address]; found {
 		existingNode.counter++