diff --git a/client.go b/client.go
index 993e7a9..d4af3f3 100644
--- a/client.go
+++ b/client.go
@@ -56,7 +56,7 @@ func NewClient(appName string, connType ClientType, opts ...ClientOption) *Clien
 		errChan:    make(chan error),
 		closeChan:  make(chan bool),
 	}
-	c.Init(opts...)
+	_ = c.Init(opts...)
 	once.Do(func() {
 		c.init()
 	})
@@ -145,8 +145,9 @@ func (c *Client) handleFrame() {
 		// this will block until a frame is received
 		f, err := fs.ReadFrame()
 		if err != nil {
-			defer c.stream.Close()
-			// defer c.conn.CloseWithError(0xD0, err.Error())
+			defer func() {
+				_ = c.stream.Close()
+			}()
 
 			c.logger.Debugf("%shandleFrame(): %T | %v", ClientLogPrefix, err, err)
 			if e, ok := err.(*quic.IdleTimeoutError); ok {
@@ -185,7 +186,7 @@ func (c *Client) handleFrame() {
 				// any error occurred, we should close the stream
 				// after this, conn.AcceptStream() will raise the error
 				c.setState(ConnStateClosed)
-				c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeUnknown), err.Error())
+				_ = c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeUnknown), err.Error())
 				c.logger.Errorf("%sunknown error occurred, err=%v, state=%v", ClientLogPrefix, err, c.getState())
 				break
 			}
@@ -210,7 +211,7 @@ func (c *Client) handleFrame() {
 			c.setState(ConnStateRejected)
 			if v, ok := f.(*frame.RejectedFrame); ok {
 				c.logger.Errorf("%s receive RejectedFrame, message=%s", ClientLogPrefix, v.Message())
-				c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeRejected), v.Message())
+				_ = c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeRejected), v.Message())
 				c.errChan <- errors.New(v.Message())
 				break
 			}
@@ -218,7 +219,7 @@ func (c *Client) handleFrame() {
 			c.setState(ConnStateGoaway)
 			if v, ok := f.(*frame.GoawayFrame); ok {
 				c.logger.Errorf("%s️ receive GoawayFrame, message=%s", ClientLogPrefix, v.Message())
-				c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeGoaway), v.Message())
+				_ = c.conn.CloseWithError(hpds_err.To(hpds_err.ErrorCodeGoaway), v.Message())
 				c.errChan <- errors.New(v.Message())
 				break
 			}
@@ -229,8 +230,6 @@ func (c *Client) handleFrame() {
 				if c.processor == nil {
 					c.logger.Warnf("%sprocessor is nil", ClientLogPrefix)
 				} else {
-					// TODO: should c.processor accept a DataFrame as parameter?
-					// c.processor(v.GetDataTagID(), v.GetCarriage(), v.GetMetaFrame())
 					c.processor(v)
 				}
 			}
diff --git a/context.go b/context.go
index 2aceb6b..6d0d2cd 100644
--- a/context.go
+++ b/context.go
@@ -54,10 +54,10 @@ func (c *Context) Clean() {
 func (c *Context) CloseWithError(code hpds_err.ErrorCode, msg string) {
 	log.Debugf("%sconn[%s] context close, errCode=%#x, msg=%s", ServerLogPrefix, c.connId, code, msg)
 	if c.Stream != nil {
-		c.Stream.Close()
+		_ = c.Stream.Close()
 	}
 	if c.Conn != nil {
-		c.Conn.CloseWithError(quic.ApplicationErrorCode(code), msg)
+		_ = c.Conn.CloseWithError(quic.ApplicationErrorCode(code), msg)
 	}
 	c.Clean()
 }
diff --git a/frame/data_frame.go b/frame/data_frame.go
index 217d943..ec0b547 100644
--- a/frame/data_frame.go
+++ b/frame/data_frame.go
@@ -71,7 +71,7 @@ func (d *DataFrame) SourceId() string {
 
 // Encode return coder encoded bytes of `DataFrame`
 func (d *DataFrame) Encode() []byte {
-	data := coder.NewNodePacketEncoder(byte(d.Type()))
+	data := coder.NewNodePacketEncoder(d.Type())
 	// MetaFrame
 	data.AddBytes(d.metaFrame.Encode())
 	// PayloadFrame
@@ -90,7 +90,7 @@ func DecodeToDataFrame(buf []byte) (*DataFrame, error) {
 
 	data := &DataFrame{}
 
-	if metaBlock, ok := packet.NodePackets[byte(TagOfMetaFrame)]; ok {
+	if metaBlock, ok := packet.NodePackets[TagOfMetaFrame]; ok {
 		meta, err := DecodeToMetaFrame(metaBlock.GetRawBytes())
 		if err != nil {
 			return nil, err
@@ -98,7 +98,7 @@ func DecodeToDataFrame(buf []byte) (*DataFrame, error) {
 		data.metaFrame = meta
 	}
 
-	if payloadBlock, ok := packet.NodePackets[byte(TagOfPayloadFrame)]; ok {
+	if payloadBlock, ok := packet.NodePackets[TagOfPayloadFrame]; ok {
 		payload, err := DecodeToPayloadFrame(payloadBlock.GetRawBytes())
 		if err != nil {
 			return nil, err
diff --git a/frame/goaway_frame.go b/frame/goaway_frame.go
index dd82a2c..33c0a8f 100644
--- a/frame/goaway_frame.go
+++ b/frame/goaway_frame.go
@@ -21,9 +21,9 @@ func (f *GoawayFrame) Type() Type {
 
 // Encode to coder encoded bytes
 func (f *GoawayFrame) Encode() []byte {
-	goaway := coder.NewNodePacketEncoder(byte(f.Type()))
+	goaway := coder.NewNodePacketEncoder(f.Type())
 	// message
-	msgBlock := coder.NewPrimitivePacketEncoder(byte(TagOfGoawayMessage))
+	msgBlock := coder.NewPrimitivePacketEncoder(TagOfGoawayMessage)
 	msgBlock.SetStringValue(f.message)
 
 	goaway.AddPrimitivePacket(msgBlock)
@@ -46,7 +46,7 @@ func DecodeToGoawayFrame(buf []byte) (*GoawayFrame, error) {
 
 	goaway := &GoawayFrame{}
 	// message
-	if msgBlock, ok := node.PrimitivePackets[byte(TagOfGoawayMessage)]; ok {
+	if msgBlock, ok := node.PrimitivePackets[TagOfGoawayMessage]; ok {
 		msg, err := msgBlock.ToUTF8String()
 		if err != nil {
 			return nil, err
diff --git a/frame/handshake_frame.go b/frame/handshake_frame.go
index 4b4cda6..e00672e 100644
--- a/frame/handshake_frame.go
+++ b/frame/handshake_frame.go
@@ -39,24 +39,24 @@ func (h *HandshakeFrame) Type() Type {
 // Encode to coder encoding.
 func (h *HandshakeFrame) Encode() []byte {
 	// name
-	nameBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeName))
+	nameBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeName)
 	nameBlock.SetStringValue(h.Name)
 	// client ID
-	idBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeId))
+	idBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeId)
 	idBlock.SetStringValue(h.ClientId)
 	// client type
-	typeBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeType))
+	typeBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeType)
 	typeBlock.SetBytesValue([]byte{h.ClientType})
 	// observe data tags
-	observeDataTagsBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeObserveDataTags))
+	observeDataTagsBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeObserveDataTags)
 	observeDataTagsBlock.SetBytesValue(h.ObserveDataTags)
 	// auth
-	authNameBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeAuthName))
+	authNameBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeAuthName)
 	authNameBlock.SetStringValue(h.authName)
-	authPayloadBlock := coder.NewPrimitivePacketEncoder(byte(TagOfHandshakeAuthPayload))
+	authPayloadBlock := coder.NewPrimitivePacketEncoder(TagOfHandshakeAuthPayload)
 	authPayloadBlock.SetStringValue(h.authPayload)
 	// handshake frame
-	handshake := coder.NewNodePacketEncoder(byte(h.Type()))
+	handshake := coder.NewNodePacketEncoder(h.Type())
 	handshake.AddPrimitivePacket(nameBlock)
 	handshake.AddPrimitivePacket(idBlock)
 	handshake.AddPrimitivePacket(typeBlock)
@@ -77,7 +77,7 @@ func DecodeToHandshakeFrame(buf []byte) (*HandshakeFrame, error) {
 
 	handshake := &HandshakeFrame{}
 	// name
-	if nameBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeName)]; ok {
+	if nameBlock, ok := node.PrimitivePackets[TagOfHandshakeName]; ok {
 		name, err := nameBlock.ToUTF8String()
 		if err != nil {
 			return nil, err
@@ -85,7 +85,7 @@ func DecodeToHandshakeFrame(buf []byte) (*HandshakeFrame, error) {
 		handshake.Name = name
 	}
 	// client id
-	if idBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeId)]; ok {
+	if idBlock, ok := node.PrimitivePackets[TagOfHandshakeId]; ok {
 		id, err := idBlock.ToUTF8String()
 		if err != nil {
 			return nil, err
@@ -93,23 +93,23 @@ func DecodeToHandshakeFrame(buf []byte) (*HandshakeFrame, error) {
 		handshake.ClientId = id
 	}
 	// client type
-	if typeBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeType)]; ok {
+	if typeBlock, ok := node.PrimitivePackets[TagOfHandshakeType]; ok {
 		clientType := typeBlock.ToBytes()
 		handshake.ClientType = clientType[0]
 	}
 	// observe data tag list
-	if observeDataTagsBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeObserveDataTags)]; ok {
+	if observeDataTagsBlock, ok := node.PrimitivePackets[TagOfHandshakeObserveDataTags]; ok {
 		handshake.ObserveDataTags = observeDataTagsBlock.ToBytes()
 	}
 	// auth
-	if authNameBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeAuthName)]; ok {
+	if authNameBlock, ok := node.PrimitivePackets[TagOfHandshakeAuthName]; ok {
 		authName, err := authNameBlock.ToUTF8String()
 		if err != nil {
 			return nil, err
 		}
 		handshake.authName = authName
 	}
-	if authPayloadBlock, ok := node.PrimitivePackets[byte(TagOfHandshakeAuthPayload)]; ok {
+	if authPayloadBlock, ok := node.PrimitivePackets[TagOfHandshakeAuthPayload]; ok {
 		authPayload, err := authPayloadBlock.ToUTF8String()
 		if err != nil {
 			return nil, err
diff --git a/frame/meta_frame.go b/frame/meta_frame.go
index e9beb32..8f95d2a 100644
--- a/frame/meta_frame.go
+++ b/frame/meta_frame.go
@@ -57,20 +57,20 @@ func (m *MetaFrame) SourceId() string {
 
 // Encode implements Frame.Encode method.
 func (m *MetaFrame) Encode() []byte {
-	meta := coder.NewNodePacketEncoder(byte(TagOfMetaFrame))
+	meta := coder.NewNodePacketEncoder(TagOfMetaFrame)
 	// transaction ID
-	transactionId := coder.NewPrimitivePacketEncoder(byte(TagOfTransactionId))
+	transactionId := coder.NewPrimitivePacketEncoder(TagOfTransactionId)
 	transactionId.SetStringValue(m.tid)
 	meta.AddPrimitivePacket(transactionId)
 
 	// source ID
-	sourceId := coder.NewPrimitivePacketEncoder(byte(TagOfSourceId))
+	sourceId := coder.NewPrimitivePacketEncoder(TagOfSourceId)
 	sourceId.SetStringValue(m.sourceId)
 	meta.AddPrimitivePacket(sourceId)
 
 	// metadata
 	if m.metadata != nil {
-		metadata := coder.NewPrimitivePacketEncoder(byte(TagOfMetadata))
+		metadata := coder.NewPrimitivePacketEncoder(TagOfMetadata)
 		metadata.SetBytesValue(m.metadata)
 		meta.AddPrimitivePacket(metadata)
 	}
@@ -89,17 +89,17 @@ func DecodeToMetaFrame(buf []byte) (*MetaFrame, error) {
 	meta := &MetaFrame{}
 	for k, v := range nodeBlock.PrimitivePackets {
 		switch k {
-		case byte(TagOfTransactionId):
+		case TagOfTransactionId:
 			val, err := v.ToUTF8String()
 			if err != nil {
 				return nil, err
 			}
 			meta.tid = val
 			break
-		case byte(TagOfMetadata):
+		case TagOfMetadata:
 			meta.metadata = v.ToBytes()
 			break
-		case byte(TagOfSourceId):
+		case TagOfSourceId:
 			sourceId, err := v.ToUTF8String()
 			if err != nil {
 				return nil, err
diff --git a/frame/payload_frame.go b/frame/payload_frame.go
index 2f1f43b..2282682 100644
--- a/frame/payload_frame.go
+++ b/frame/payload_frame.go
@@ -30,7 +30,7 @@ func (m *PayloadFrame) Encode() []byte {
 	carriage := coder.NewPrimitivePacketEncoder(m.Tag)
 	carriage.SetBytesValue(m.Carriage)
 
-	payload := coder.NewNodePacketEncoder(byte(TagOfPayloadFrame))
+	payload := coder.NewNodePacketEncoder(TagOfPayloadFrame)
 	payload.AddPrimitivePacket(carriage)
 
 	return payload.Encode()
diff --git a/frame/rejected_frame.go b/frame/rejected_frame.go
index 9cb5db4..bc27bfe 100644
--- a/frame/rejected_frame.go
+++ b/frame/rejected_frame.go
@@ -21,9 +21,9 @@ func (f *RejectedFrame) Type() Type {
 
 // Encode to coder encoded bytes
 func (f *RejectedFrame) Encode() []byte {
-	rejected := coder.NewNodePacketEncoder(byte(f.Type()))
+	rejected := coder.NewNodePacketEncoder(f.Type())
 	// message
-	msgBlock := coder.NewPrimitivePacketEncoder(byte(TagOfRejectedMessage))
+	msgBlock := coder.NewPrimitivePacketEncoder(TagOfRejectedMessage)
 	msgBlock.SetStringValue(f.message)
 
 	rejected.AddPrimitivePacket(msgBlock)
@@ -45,7 +45,7 @@ func DecodeToRejectedFrame(buf []byte) (*RejectedFrame, error) {
 	}
 	rejected := &RejectedFrame{}
 	// message
-	if msgBlock, ok := node.PrimitivePackets[byte(TagOfRejectedMessage)]; ok {
+	if msgBlock, ok := node.PrimitivePackets[TagOfRejectedMessage]; ok {
 		msg, e := msgBlock.ToUTF8String()
 		if e != nil {
 			return nil, e
diff --git a/log/zap.go b/log/zap.go
index c81043c..6e94f01 100644
--- a/log/zap.go
+++ b/log/zap.go
@@ -130,12 +130,12 @@ func (z *zapLogger) Infof(template string, args ...interface{}) {
 }
 
 // Warnf logs a message at WarnLevel
-func (z zapLogger) Warnf(template string, args ...interface{}) {
+func (z *zapLogger) Warnf(template string, args ...interface{}) {
 	z.Instance().Warnf(template, args...)
 }
 
 // Errorf logs a message at ErrorLevel
-func (z zapLogger) Errorf(template string, args ...interface{}) {
+func (z *zapLogger) Errorf(template string, args ...interface{}) {
 	z.Instance().Errorf(template, args...)
 }
 
@@ -190,7 +190,7 @@ func (z *zapLogger) Instance() *zap.SugaredLogger {
 					if err != nil {
 						return err
 					}
-					rotatedLogger.Write(msg.Bytes())
+					_, _ = rotatedLogger.Write(msg.Bytes())
 				}
 				return nil
 			})
@@ -204,11 +204,11 @@ func (z *zapLogger) Instance() *zap.SugaredLogger {
 	return z.instance
 }
 
-func errorRotatedLogger(file string, maxSize, maxBacukups, maxAge int) *lumberjack.Logger {
+func errorRotatedLogger(file string, maxSize, maxBackups, maxAge int) *lumberjack.Logger {
 	return &lumberjack.Logger{
 		Filename:   file,
 		MaxSize:    maxSize,
-		MaxBackups: maxBacukups,
+		MaxBackups: maxBackups,
 		MaxAge:     maxAge,
 		Compress:   false,
 	}
@@ -221,7 +221,7 @@ func timeEncoder(t time.Time, enc zapcore.PrimitiveArrayEncoder) {
 type logWriter struct{}
 
 func (l logWriter) Write(bytes []byte) (int, error) {
-	os.Stderr.WriteString(time.Now().Format(timeFormat))
-	os.Stderr.Write([]byte("\t"))
+	_, _ = os.Stderr.WriteString(time.Now().Format(timeFormat))
+	_, _ = os.Stderr.Write([]byte("\t"))
 	return os.Stderr.Write(bytes)
 }
diff --git a/server.go b/server.go
index 87362ba..b0b9a56 100644
--- a/server.go
+++ b/server.go
@@ -52,7 +52,7 @@ func NewServer(name string, opts ...ServerOption) *Server {
 		connector:   newConnector(),
 		downStreams: make(map[string]*Client),
 	}
-	s.Init(opts...)
+	_ = s.Init(opts...)
 
 	return s
 }
@@ -100,59 +100,74 @@ func (s *Server) Serve(ctx context.Context, conn net.PacketConn) error {
 		log.Errorf("%slistener.Listen: err=%v", ServerLogPrefix, err)
 		return err
 	}
-	defer listener.Close()
+	defer func() {
+		_ = listener.Close()
+	}()
 	log.Printf("%s [%s][%d] Listening on: %s, MODE: %s, QUIC: %v, AUTH: %s", ServerLogPrefix, s.name, os.Getpid(), listener.Addr(), mode(), listener.Versions(), s.authNames())
 
 	s.state = ConnStateConnected
 	for {
-		// create a new connection when new hpds-client connected
-		sctx, cancel := context.WithCancel(ctx)
-		defer cancel()
-
-		connect, e := listener.Accept(sctx)
-		if e != nil {
-			log.Errorf("%screate connection error: %v", ServerLogPrefix, e)
-			return e
-		}
-
-		connID := GetConnId(connect)
-		log.Infof("%s1/ new connection: %s", ServerLogPrefix, connID)
-
-		go func(ctx context.Context, qconn quic.Connection) {
-			for {
-				log.Infof("%s2/ waiting for new stream", ServerLogPrefix)
-				stream, err := qconn.AcceptStream(ctx)
-				if err != nil {
-					// if client close the connection, then we should close the connection
-					// @CC: when Source close the connection, it won't affect connectors
-					name := "--"
-					if conn := s.connector.Get(connID); conn != nil {
-						conn.Close()
-						// connector
-						s.connector.Remove(connID)
-						route := s.router.Route(conn.Metadata())
-						if route != nil {
-							route.Remove(connID)
-						}
-						name = conn.Name()
-					}
-					log.Printf("%s [%s](%s) close the connection: %v", ServerLogPrefix, name, connID, err)
-					break
-				}
-				defer stream.Close()
-
-				log.Infof("%s3/ [stream:%d] created, connId=%s", ServerLogPrefix, stream.StreamID(), connID)
-				// process frames on stream
-				// c := newContext(connId, stream)
-				c := newContext(connect, stream)
-				defer c.Clean()
-				s.handleConnection(c)
-				log.Infof("%s4/ [stream:%d] handleConnection DONE", ServerLogPrefix, stream.StreamID())
-			}
-		}(sctx, connect)
+		_ = s.createNewClientConnection(ctx, listener)
 	}
 }
 
+// createNewClientConnection create a new connection when new hpds-client connected
+func (s *Server) createNewClientConnection(ctx context.Context, listener Listener) error {
+	sctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	connect, e := listener.Accept(sctx)
+	if e != nil {
+		log.Errorf("%screate connection error: %v", ServerLogPrefix, e)
+		return e
+	}
+
+	connId := GetConnId(connect)
+	log.Infof("%s1/ new connection: %s", ServerLogPrefix, connId)
+
+	go func(ctx context.Context, qConn quic.Connection) {
+		for {
+			err := s.handle(ctx, qConn, connect, connId)
+			if err != nil {
+				break
+			}
+		}
+	}(sctx, connect)
+	return nil
+}
+
+func (s *Server) handle(ctx context.Context, qConn quic.Connection, conn quic.Connection, connId string) error {
+	log.Infof("%s2/ waiting for new stream", ServerLogPrefix)
+	stream, err := qConn.AcceptStream(ctx)
+	if err != nil {
+		name := "--"
+		if conn := s.connector.Get(connId); conn != nil {
+			_ = conn.Close()
+			// connector
+			s.connector.Remove(connId)
+			route := s.router.Route(conn.Metadata())
+			if route != nil {
+				_ = route.Remove(connId)
+			}
+			name = conn.Name()
+		}
+		log.Printf("%s [%s](%s) close the connection: %v", ServerLogPrefix, name, connId, err)
+		return err
+	}
+	defer func() {
+		_ = stream.Close()
+	}()
+
+	log.Infof("%s3/ [stream:%d] created, connId=%s", ServerLogPrefix, stream.StreamID(), connId)
+	// process frames on stream
+	// c := newContext(connId, stream)
+	c := newContext(conn, stream)
+	defer c.Clean()
+	s.handleConnection(c)
+	log.Infof("%s4/ [stream:%d] handleConnection DONE", ServerLogPrefix, stream.StreamID())
+	return nil
+}
+
 // Close will shut down the server.
 func (s *Server) Close() error {
 	if s.router != nil {
@@ -204,28 +219,28 @@ func (s *Server) handleConnection(c *Context) {
 		frameType := f.Type()
 		data := f.Encode()
 		log.Debugf("%stype=%s, frame[%d]=%# x", ServerLogPrefix, frameType, len(data), frame.Shortly(data))
-		// add frame to context
-		context := c.WithFrame(f)
+		// add frame to contextFrame
+		contextFrame := c.WithFrame(f)
 
 		// before frame handlers
 		for _, handler := range s.beforeHandlers {
-			if e := handler(context); e != nil {
+			if e := handler(contextFrame); e != nil {
 				log.Errorf("%safterFrameHandler e: %s", ServerLogPrefix, e)
-				context.CloseWithError(hpds_err.ErrorCodeBeforeHandler, e.Error())
+				contextFrame.CloseWithError(hpds_err.ErrorCodeBeforeHandler, e.Error())
 				return
 			}
 		}
 		// main handler
-		if e := s.mainFrameHandler(context); e != nil {
+		if e := s.mainFrameHandler(contextFrame); e != nil {
 			log.Errorf("%smainFrameHandler e: %s", ServerLogPrefix, e)
-			context.CloseWithError(hpds_err.ErrorCodeMainHandler, e.Error())
+			contextFrame.CloseWithError(hpds_err.ErrorCodeMainHandler, e.Error())
 			return
 		}
 		// after frame handler
 		for _, handler := range s.afterHandlers {
-			if e := handler(context); e != nil {
+			if e := handler(contextFrame); e != nil {
 				log.Errorf("%safterFrameHandler e: %s", ServerLogPrefix, e)
-				context.CloseWithError(hpds_err.ErrorCodeAfterHandler, e.Error())
+				contextFrame.CloseWithError(hpds_err.ErrorCodeAfterHandler, e.Error())
 				return
 			}
 		}
@@ -262,7 +277,7 @@ func (s *Server) mainFrameHandler(c *Context) error {
 				s.dispatchToDownStreams(f)
 			}
 			// observe data tags back flow
-			s.handleBackFlowFrame(c)
+			_ = s.handleBackFlowFrame(c)
 		}
 	default:
 		log.Errorf("%serr=%v, frame=%v", ServerLogPrefix, err, frame.Shortly(c.Frame.Encode()))
@@ -334,7 +349,7 @@ func (s *Server) handleHandshakeFrame(c *Context) error {
 	default:
 		// unknown client type
 		s.connector.Remove(connId)
-		err := fmt.Errorf("Illegal ClientType: %#x", f.ClientType)
+		err := fmt.Errorf("Illegal ClientType: %#x ", f.ClientType)
 		c.CloseWithError(hpds_err.ErrorCodeUnknownClient, err.Error())
 		return err
 	}
@@ -477,7 +492,7 @@ func (s *Server) AddDownstreamServer(addr string, c *Client) {
 func (s *Server) dispatchToDownStreams(df *frame.DataFrame) {
 	for addr, ds := range s.downStreams {
 		log.Debugf("%sdispatching to [%s]: %# x", ServerLogPrefix, addr, df.Tag())
-		ds.WriteFrame(df)
+		_ = ds.WriteFrame(df)
 	}
 }
 
diff --git a/tls/tls.go b/tls/tls.go
index 30de2c2..ff444a7 100644
--- a/tls/tls.go
+++ b/tls/tls.go
@@ -10,7 +10,6 @@ import (
 	"crypto/x509/pkix"
 	"encoding/pem"
 	"errors"
-	"io/ioutil"
 	"math/big"
 	"net"
 	"os"
@@ -88,7 +87,7 @@ func getCACertPool() (*x509.CertPool, error) {
 		return nil, errors.New("tls: must provide CA certificate on production mode, you can configure this via environment variables: `HPDS_TLS_CACERT_FILE`")
 	}
 
-	caCert, err = ioutil.ReadFile(caCertPath)
+	caCert, err = os.ReadFile(caCertPath)
 	if err != nil {
 		return nil, err
 	}
@@ -116,12 +115,12 @@ func getCertAndKey() (*tls.Certificate, error) {
 	}
 
 	// certificate
-	cert, err = ioutil.ReadFile(certPath)
+	cert, err = os.ReadFile(certPath)
 	if err != nil {
 		return nil, err
 	}
 	// private key
-	key, err = ioutil.ReadFile(keyPath)
+	key, err = os.ReadFile(keyPath)
 	if err != nil {
 		return nil, err
 	}