diff --git a/client/socket.go b/client/socket.go
index f9e26e3..c896f32 100644
--- a/client/socket.go
+++ b/client/socket.go
@@ -17,18 +17,18 @@ type Socket interface {
 
 func NewSocket(sb SocketBuilder, parentContext cuc.Context) (Socket, error) {
 	if nil == sb {
-		logging.Logger().Panic("Client Socket: SocketBuilder must be specified")
+		logging.Logger().Panicf("Client Socket: SocketBuilder must be specified")
 	}
 	sb.Validate()
 
 	sc := sb.SocketContext(parentContext)
 	if nil == sc {
-		logging.Logger().Panic("Client Socket: SocketContext must be specified")
+		logging.Logger().Panicf("Client Socket: SocketContext must be specified")
 	}
 
 	sh := sb.GetSocketHandler()
 	if nil == sh {
-		logging.Logger().Panic("Client Socket: SocketHandler must be specified")
+		logging.Logger().Panicf("Client Socket: SocketHandler must be specified")
 	}
 	sh.Validate()
 
diff --git a/client/socket_builders.go b/client/socket_builders.go
index d53cee6..a2731a1 100644
--- a/client/socket_builders.go
+++ b/client/socket_builders.go
@@ -71,14 +71,14 @@ func (sb *SocketBuilders) GetLocalAddress() net.Addr {
 
 func (sb *SocketBuilders) Validate() {
 	if nil == sb.SocketHandler {
-		logging.Logger().Panic("Client Socket: SocketHandler must be specified")
+		logging.Logger().Panicf("Client Socket: SocketHandler must be specified")
 	}
 
 	if "" == sb.Network {
-		logging.Logger().Panic("Client Socket: Network must be specified")
+		logging.Logger().Panicf("Client Socket: Network must be specified")
 	}
 	if "" == sb.Address {
-		logging.Logger().Panic("Client Socket: Address must be specified")
+		logging.Logger().Panicf("Client Socket: Address must be specified")
 	}
 
 	if 0 >= sb.KeepAlive {
diff --git a/server.go b/server.go
index 8fc1409..9a46b80 100644
--- a/server.go
+++ b/server.go
@@ -75,7 +75,7 @@ func (s *server) Stop() {
 
 	s.sh.OnStop(s.ctx)
 
-	logging.Logger().Info(fmt.Sprintf("Server[%s] is stopped", s.sh.GetName()))
+	logging.Logger().Infof("Server[%s] is stopped", s.sh.GetName())
 }
 
 func (s *server) Context() ServerContext {
@@ -85,7 +85,7 @@ func (s *server) Context() ServerContext {
 func handleServer(s *server) {
 	defer s.stopWg.Done()
 
-	logging.Logger().Info(fmt.Sprintf("Server[%s] is started", s.sh.GetName()))
+	logging.Logger().Infof("Server[%s] is started", s.sh.GetName())
 	s.sh.OnStart(s.ctx)
 
 	var conn net.Conn
@@ -97,7 +97,7 @@ func handleServer(s *server) {
 		go func() {
 			if conn, err = s.listener.Accept(); err != nil {
 				if stopping.Load() == nil {
-					logging.Logger().Error(fmt.Sprintf("Server: Cannot accept new connection: [%s]", err))
+					logging.Logger().Errorf("Server: Cannot accept new connection: [%s]", err)
 				}
 			}
 			close(acceptChan)
@@ -128,12 +128,12 @@ func handleServer(s *server) {
 		socketCTX := socketHandler.SocketContext(s.ctx)
 
 		if socketID = socketHandler.Handshake(socketCTX, conn); "" == socketID {
-			logging.Logger().Error(fmt.Sprintf("Server: Handshake err addr[%s] %v", conn.RemoteAddr(), conn))
+			logging.Logger().Errorf("Server: Handshake err addr[%s] %v", conn.RemoteAddr(), conn)
 			conn.Close()
 			continue
 		}
 		soc := newSocket(socketHandler, socketCTX, conn, socketID)
-		logging.Logger().Debug(fmt.Sprintf("Server: Client[%s] is connected.", soc.RemoteAddr()))
+		logging.Logger().Debugf("Server: Client[%s] is connected.", soc.RemoteAddr())
 
 		socketHandler.addSocket(soc)
 		socketHandler.OnConnect(soc)
@@ -158,7 +158,7 @@ func handleConnection(s *server, soc Socket, socketHandler SocketHandler) {
 	case <-handleDoneChan:
 		close(clientStopChan)
 		socketHandler.OnDisconnect(soc)
-		logging.Logger().Debug(fmt.Sprintf("Server: Client[%s] is disconnected.", soc.RemoteAddr()))
+		logging.Logger().Debugf("Server: Client[%s] is disconnected.", soc.RemoteAddr())
 		socketHandler.removeSocket(soc)
 		soc.Close()
 	}
diff --git a/server_handlers.go b/server_handlers.go
index 779c02a..7261db3 100644
--- a/server_handlers.go
+++ b/server_handlers.go
@@ -43,7 +43,7 @@ func (sh *ServerHandlers) OnStart(serverCTX ServerContext) {
 }
 
 func (sh *ServerHandlers) OnError(serverCTX ServerContext, conn net.Conn, status int, reason error) {
-	logging.Logger().Error(fmt.Sprintf("Server: error status: %d, reason: %v, [%v]", status, reason, conn))
+	logging.Logger().Errorf("Server: error status: %d, reason: %v, [%v]", status, reason, conn)
 }
 
 // OnStop invoked when server is stopped
@@ -62,6 +62,6 @@ func (sh *ServerHandlers) GetSocketHandler() SocketHandler {
 
 func (sh *ServerHandlers) Validate() {
 	if nil == sh.SocketHandler {
-		panic("Server: SocketHandler must be specified")
+		logging.Logger().Panicf("Server: SocketHandler must be specified")
 	}
 }