fix: duplicated start grpc client

core/grpc/client/client_v2.go

@@ -36,6 +36,7 @@ type GrpcClientV2 struct {
 	stream grpc2.NodeService_SubscribeClient
 	msgCh  chan *grpc2.StreamMessage
 	err    error
+	once   sync.Once
 
 	// clients
 	NodeClient               grpc2.NodeServiceClient
@@ -46,23 +47,27 @@ type GrpcClientV2 struct {
 }
 
 func (c *GrpcClientV2) Start() (err error) {
+	c.once.Do(func() {
 		// connect
-	if err := c.connect(); err != nil {
-		return err
+		err = c.connect()
+		if err != nil {
+			return
 		}
 
 		// register rpc services
 		c.Register()
 
 		// subscribe
-	if err := c.subscribe(); err != nil {
-		return err
+		err = c.subscribe()
+		if err != nil {
+			return
 		}
 
 		// handle stream message
 		go c.handleStreamMessage()
+	})
 
-	return nil
+	return err
 }
 
 func (c *GrpcClientV2) Stop() (err error) {

core/grpc/server/node_server_v2.go

@@ -69,7 +69,7 @@ func (svr NodeServerV2) Register(ctx context.Context, req *grpc.Request) (res *g
 			if err != nil {
 				return HandleError(err)
 			}
-			log.Infof("[NodeServerV2] updated worker[%s] in db. id: %s", nodeKey, node.Id.Hex())
+			log.Infof("[NodeServerV2] updated worker[%s] in db. id: %s", nodeKey, nodeDb.Id.Hex())
 		}
 	} else if errors2.Is(err, mongo.ErrNoDocuments) {
 		// register new