diff --git a/pkg/proxy/backend/backend_conn_mgr.go b/pkg/proxy/backend/backend_conn_mgr.go
index 26dc7eb6..ed236e95 100644
--- a/pkg/proxy/backend/backend_conn_mgr.go
+++ b/pkg/proxy/backend/backend_conn_mgr.go
@@ -106,11 +106,11 @@ type BackendConnManager struct {
 	closeStatus   atomic.Int32
 	// cancelFunc is used to cancel the signal processing goroutine.
 	cancelFunc       context.CancelFunc
+	clientIO         *pnet.PacketIO
 	backendIO        *pnet.PacketIO
 	backendTLS       *tls.Config
 	handshakeHandler HandshakeHandler
 	ctxmap           sync.Map
-	clientAddr       string
 	connectionID     uint64
 }
 
@@ -147,7 +147,7 @@ func (mgr *BackendConnManager) Connect(ctx context.Context, clientIO *pnet.Packe
 
 	mgr.backendTLS = backendTLSConfig
 
-	mgr.clientAddr = clientIO.RemoteAddr().String()
+	mgr.clientIO = clientIO
 	err := mgr.authenticator.handshakeFirstTime(mgr.logger.Named("authenticator"), mgr, clientIO, mgr.handshakeHandler, mgr.getBackendIO, frontendTLSConfig, backendTLSConfig)
 	mgr.handshakeHandler.OnHandshake(mgr, mgr.ServerAddr(), err)
 	if err != nil {
@@ -158,7 +158,7 @@ func (mgr *BackendConnManager) Connect(ctx context.Context, clientIO *pnet.Packe
 	childCtx, cancelFunc := context.WithCancel(ctx)
 	mgr.cancelFunc = cancelFunc
 	mgr.wg.Run(func() {
-		mgr.processSignals(childCtx, clientIO)
+		mgr.processSignals(childCtx)
 	})
 	return nil
 }
@@ -219,7 +219,7 @@ func (mgr *BackendConnManager) getBackendIO(cctx ConnContext, auth *Authenticato
 
 // ExecuteCmd forwards messages between the client and the backend.
 // If it finds that the session is ready for redirection, it migrates the session.
-func (mgr *BackendConnManager) ExecuteCmd(ctx context.Context, request []byte, clientIO *pnet.PacketIO) error {
+func (mgr *BackendConnManager) ExecuteCmd(ctx context.Context, request []byte) error {
 	if len(request) < 1 {
 		return mysql.ErrMalformPacket
 	}
@@ -233,7 +233,7 @@ func (mgr *BackendConnManager) ExecuteCmd(ctx context.Context, request []byte, c
 		return nil
 	}
 	waitingRedirect := atomic.LoadPointer(&mgr.signal) != nil
-	holdRequest, err := mgr.cmdProcessor.executeCmd(request, clientIO, mgr.backendIO, waitingRedirect)
+	holdRequest, err := mgr.cmdProcessor.executeCmd(request, mgr.clientIO, mgr.backendIO, waitingRedirect)
 	if !holdRequest {
 		addCmdMetrics(cmd, mgr.ServerAddr(), startTime)
 	}
@@ -269,17 +269,17 @@ func (mgr *BackendConnManager) ExecuteCmd(ctx context.Context, request []byte, c
 	// Even if it meets an MySQL error, it may have changed the status, such as when executing multi-statements.
 	if mgr.cmdProcessor.finishedTxn() {
 		if waitingRedirect && holdRequest {
-			mgr.tryRedirect(ctx, clientIO)
+			mgr.tryRedirect(ctx)
 			// Execute the held request no matter redirection succeeds or not.
-			_, err = mgr.cmdProcessor.executeCmd(request, clientIO, mgr.backendIO, false)
+			_, err = mgr.cmdProcessor.executeCmd(request, mgr.clientIO, mgr.backendIO, false)
 			addCmdMetrics(cmd, mgr.ServerAddr(), startTime)
 			if err != nil && !IsMySQLError(err) {
 				return err
 			}
 		} else if mgr.closeStatus.Load() == statusNotifyClose {
-			mgr.tryGracefulClose(ctx, clientIO)
+			mgr.tryGracefulClose(ctx)
 		} else if waitingRedirect {
-			mgr.tryRedirect(ctx, clientIO)
+			mgr.tryRedirect(ctx)
 		}
 	}
 	// Ignore MySQL errors, only return unexpected errors.
@@ -325,7 +325,7 @@ func (mgr *BackendConnManager) querySessionStates() (sessionStates, sessionToken
 // processSignals runs in a goroutine to:
 // - Receive redirection signals and then try to migrate the session.
 // - Send redirection results to the event receiver.
-func (mgr *BackendConnManager) processSignals(ctx context.Context, clientIO *pnet.PacketIO) {
+func (mgr *BackendConnManager) processSignals(ctx context.Context) {
 	for {
 		select {
 		case s := <-mgr.signalReceived:
@@ -333,9 +333,9 @@ func (mgr *BackendConnManager) processSignals(ctx context.Context, clientIO *pne
 			mgr.processLock.Lock()
 			switch s {
 			case signalTypeGracefulClose:
-				mgr.tryGracefulClose(ctx, clientIO)
+				mgr.tryGracefulClose(ctx)
 			case signalTypeRedirect:
-				mgr.tryRedirect(ctx, clientIO)
+				mgr.tryRedirect(ctx)
 			}
 			mgr.processLock.Unlock()
 		case rs := <-mgr.redirectResCh:
@@ -348,7 +348,7 @@ func (mgr *BackendConnManager) processSignals(ctx context.Context, clientIO *pne
 
 // tryRedirect tries to migrate the session if the session is redirect-able.
 // NOTE: processLock should be held before calling this function.
-func (mgr *BackendConnManager) tryRedirect(ctx context.Context, clientIO *pnet.PacketIO) {
+func (mgr *BackendConnManager) tryRedirect(ctx context.Context) {
 	switch mgr.closeStatus.Load() {
 	case statusNotifyClose, statusClosing, statusClosed:
 		return
@@ -389,8 +389,7 @@ func (mgr *BackendConnManager) tryRedirect(ctx context.Context, clientIO *pnet.P
 	}
 	newBackendIO := pnet.NewPacketIO(cn, pnet.WithRemoteAddr(rs.to))
 
-	mgr.clientAddr = clientIO.RemoteAddr().String()
-	if rs.err = mgr.authenticator.handshakeSecondTime(mgr.logger, clientIO, newBackendIO, mgr.backendTLS, sessionToken); rs.err == nil {
+	if rs.err = mgr.authenticator.handshakeSecondTime(mgr.logger, mgr.clientIO, newBackendIO, mgr.backendTLS, sessionToken); rs.err == nil {
 		rs.err = mgr.initSessionStates(newBackendIO, sessionStates)
 	} else {
 		mgr.handshakeHandler.OnHandshake(mgr, newBackendIO.RemoteAddr().String(), rs.err)
@@ -475,7 +474,7 @@ func (mgr *BackendConnManager) GracefulClose() {
 	mgr.signalReceived <- signalTypeGracefulClose
 }
 
-func (mgr *BackendConnManager) tryGracefulClose(ctx context.Context, clientIO *pnet.PacketIO) {
+func (mgr *BackendConnManager) tryGracefulClose(ctx context.Context) {
 	if mgr.closeStatus.Load() != statusNotifyClose {
 		return
 	}
@@ -483,20 +482,40 @@ func (mgr *BackendConnManager) tryGracefulClose(ctx context.Context, clientIO *p
 		return
 	}
 	// Closing clientIO will cause the whole connection to be closed.
-	if err := clientIO.GracefulClose(); err != nil {
-		mgr.logger.Warn("graceful close client IO error", zap.Stringer("addr", clientIO.RemoteAddr()), zap.Error(err))
+	if err := mgr.clientIO.GracefulClose(); err != nil {
+		mgr.logger.Warn("graceful close client IO error", zap.Stringer("addr", mgr.clientIO.RemoteAddr()), zap.Error(err))
 	}
 	mgr.closeStatus.Store(statusClosing)
 }
 
 func (mgr *BackendConnManager) ClientAddr() string {
-	return mgr.clientAddr
+	if mgr.clientIO == nil {
+		return ""
+	}
+	return mgr.clientIO.RemoteAddr().String()
 }
 
 func (mgr *BackendConnManager) ServerAddr() string {
+	if mgr.backendIO == nil {
+		return ""
+	}
 	return mgr.backendIO.RemoteAddr().String()
 }
 
+func (mgr *BackendConnManager) ClientInBytes() uint64 {
+	if mgr.clientIO == nil {
+		return 0
+	}
+	return mgr.clientIO.InBytes()
+}
+
+func (mgr *BackendConnManager) ClientOutBytes() uint64 {
+	if mgr.clientIO == nil {
+		return 0
+	}
+	return mgr.clientIO.OutBytes()
+}
+
 func (mgr *BackendConnManager) SetValue(key, val any) {
 	mgr.ctxmap.Store(key, val)
 }
diff --git a/pkg/proxy/backend/backend_conn_mgr_test.go b/pkg/proxy/backend/backend_conn_mgr_test.go
index fc74469f..5329e41f 100644
--- a/pkg/proxy/backend/backend_conn_mgr_test.go
+++ b/pkg/proxy/backend/backend_conn_mgr_test.go
@@ -159,7 +159,7 @@ func (ts *backendMgrTester) forwardCmd4Proxy(clientIO, backendIO *pnet.PacketIO)
 	require.NoError(ts.t, err)
 	prevCounter, err := readCmdCounter(request[0], ts.tc.backendListener.Addr().String())
 	require.NoError(ts.t, err)
-	rsErr := ts.mp.ExecuteCmd(context.Background(), request, clientIO)
+	rsErr := ts.mp.ExecuteCmd(context.Background(), request)
 	curCounter, err := readCmdCounter(request[0], ts.tc.backendListener.Addr().String())
 	require.NoError(ts.t, err)
 	require.Equal(ts.t, prevCounter+1, curCounter)
@@ -225,6 +225,8 @@ func (ts *backendMgrTester) checkConnClosed(_, _ *pnet.PacketIO) error {
 func (ts *backendMgrTester) runTests(runners []runner) {
 	for _, runner := range runners {
 		ts.runAndCheck(ts.t, nil, runner.client, runner.backend, runner.proxy)
+		require.Equal(ts.t, ts.tc.clientIO.InBytes(), ts.mp.ClientOutBytes())
+		require.Equal(ts.t, ts.tc.clientIO.OutBytes(), ts.mp.ClientInBytes())
 	}
 }
 
diff --git a/pkg/proxy/backend/handshake_handler.go b/pkg/proxy/backend/handshake_handler.go
index 84407907..07b12db9 100644
--- a/pkg/proxy/backend/handshake_handler.go
+++ b/pkg/proxy/backend/handshake_handler.go
@@ -27,6 +27,8 @@ var _ HandshakeHandler = (*DefaultHandshakeHandler)(nil)
 type ConnContext interface {
 	ClientAddr() string
 	ServerAddr() string
+	ClientInBytes() uint64
+	ClientOutBytes() uint64
 	SetValue(key, val any)
 	Value(key any) any
 }
diff --git a/pkg/proxy/backend/testsuite_test.go b/pkg/proxy/backend/testsuite_test.go
index 01621fe2..609b9f9a 100644
--- a/pkg/proxy/backend/testsuite_test.go
+++ b/pkg/proxy/backend/testsuite_test.go
@@ -171,6 +171,8 @@ func (ts *testSuite) runAndCheck(t *testing.T, c checker, clientRunner, backendR
 			// Ensure all the packets are forwarded.
 			msg := fmt.Sprintf("cmd:%d responseType:%d", ts.mc.cmd, ts.mb.respondType)
 			require.Equal(t, ts.tc.backendIO.GetSequence(), ts.tc.clientIO.GetSequence(), msg)
+			require.Equal(t, ts.tc.clientIO.OutBytes(), ts.tc.proxyCIO.InBytes(), msg)
+			require.Equal(t, ts.tc.clientIO.InBytes(), ts.tc.proxyCIO.OutBytes(), msg)
 		}
 	} else {
 		c(t, ts)
diff --git a/pkg/proxy/client/client_conn.go b/pkg/proxy/client/client_conn.go
index bb23cdfd..d9760c04 100644
--- a/pkg/proxy/client/client_conn.go
+++ b/pkg/proxy/client/client_conn.go
@@ -87,7 +87,7 @@ func (cc *ClientConnection) processMsg(ctx context.Context) error {
 		if err != nil {
 			return err
 		}
-		err = cc.connMgr.ExecuteCmd(ctx, clientPkt, cc.pkt)
+		err = cc.connMgr.ExecuteCmd(ctx, clientPkt)
 		if err != nil {
 			return err
 		}
diff --git a/pkg/proxy/net/packetio.go b/pkg/proxy/net/packetio.go
index bedf3fcf..8f11a4ec 100644
--- a/pkg/proxy/net/packetio.go
+++ b/pkg/proxy/net/packetio.go
@@ -74,6 +74,8 @@ func (f *rdbufConn) Read(b []byte) (int, error) {
 
 // PacketIO is a helper to read and write sql and proxy protocol.
 type PacketIO struct {
+	inBytes     uint64
+	outBytes    uint64
 	conn        net.Conn
 	buf         *bufio.ReadWriter
 	proxyInited *atomic.Bool
@@ -142,6 +144,7 @@ func (p *PacketIO) readOnePacket() ([]byte, bool, error) {
 	if _, err := io.ReadFull(p.conn, header[:]); err != nil {
 		return nil, false, errors.Wrap(ErrReadConn, err)
 	}
+	p.inBytes += 4
 
 	// probe proxy V2
 	refill := false
@@ -164,6 +167,7 @@ func (p *PacketIO) readOnePacket() ([]byte, bool, error) {
 		if _, err := io.ReadFull(p.conn, header[:]); err != nil {
 			return nil, false, errors.Wrap(ErrReadConn, err)
 		}
+		p.inBytes += 4
 	}
 
 	sequence := header[3]
@@ -177,6 +181,7 @@ func (p *PacketIO) readOnePacket() ([]byte, bool, error) {
 	if _, err := io.ReadFull(p.conn, data); err != nil {
 		return nil, false, errors.Wrap(ErrReadConn, err)
 	}
+	p.inBytes += uint64(length)
 	return data, length == mysql.MaxPayloadLen, nil
 }
 
@@ -214,10 +219,12 @@ func (p *PacketIO) writeOnePacket(data []byte) (int, bool, error) {
 	if _, err := io.Copy(p.buf, bytes.NewReader(header[:])); err != nil {
 		return 0, more, errors.Wrap(ErrWriteConn, err)
 	}
+	p.outBytes += 4
 
 	if _, err := io.Copy(p.buf, bytes.NewReader(data[:length])); err != nil {
 		return 0, more, errors.Wrap(ErrWriteConn, err)
 	}
+	p.outBytes += uint64(length)
 
 	return length, more, nil
 }
@@ -239,6 +246,14 @@ func (p *PacketIO) WritePacket(data []byte, flush bool) (err error) {
 	return nil
 }
 
+func (p *PacketIO) InBytes() uint64 {
+	return p.inBytes
+}
+
+func (p *PacketIO) OutBytes() uint64 {
+	return p.outBytes
+}
+
 func (p *PacketIO) Flush() error {
 	if err := p.buf.Flush(); err != nil {
 		return p.wrapErr(errors.Wrap(ErrFlushConn, err))
diff --git a/pkg/proxy/net/packetio_test.go b/pkg/proxy/net/packetio_test.go
index 2c9c8924..54e78741 100644
--- a/pkg/proxy/net/packetio_test.go
+++ b/pkg/proxy/net/packetio_test.go
@@ -88,8 +88,11 @@ func TestPacketIO(t *testing.T) {
 			// send anything
 			require.NoError(t, cli.WritePacket(expectMsg, true))
 
+			outBytes := len(expectMsg) + 4
 			for _, l := range pktLengths {
 				require.NoError(t, cli.WritePacket(make([]byte, l), true))
+				outBytes += l + (l/(mysql.MaxPayloadLen)+1)*4
+				require.Equal(t, uint64(outBytes), cli.OutBytes())
 			}
 
 			// skip handshake
@@ -116,10 +119,13 @@ func TestPacketIO(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, expectMsg, msg)
 
+			inBytes := len(expectMsg) + 4
 			for _, l := range pktLengths {
 				msg, err = srv.ReadPacket()
 				require.NoError(t, err)
 				require.Equal(t, l, len(msg))
+				inBytes += l + (l/(mysql.MaxPayloadLen)+1)*4
+				require.Equal(t, uint64(inBytes), srv.InBytes())
 			}
 
 			// send handshake
diff --git a/pkg/proxy/net/proxy.go b/pkg/proxy/net/proxy.go
index cc228b7d..b672913a 100644
--- a/pkg/proxy/net/proxy.go
+++ b/pkg/proxy/net/proxy.go
@@ -167,12 +167,14 @@ func (p *PacketIO) parseProxyV2() (*Proxy, error) {
 	if err != nil {
 		return nil, errors.WithStack(errors.Wrap(ErrReadConn, err))
 	}
+	p.inBytes += 8
 
 	var hdr [4]byte
 
 	if _, err := io.ReadFull(p.buf, hdr[:]); err != nil {
 		return nil, errors.WithStack(err)
 	}
+	p.inBytes += 4
 
 	m := &Proxy{}
 	m.Version = ProxyVersion(hdr[0] >> 4)
@@ -182,6 +184,7 @@ func (p *PacketIO) parseProxyV2() (*Proxy, error) {
 	if _, err := io.ReadFull(p.buf, buf); err != nil {
 		return nil, errors.WithStack(err)
 	}
+	p.inBytes += uint64(len(buf))
 
 	addressFamily := ProxyAddressFamily(hdr[1] >> 4)
 	network := ProxyNetwork(hdr[1] & 0xF)
@@ -285,6 +288,7 @@ func (p *PacketIO) WriteProxyV2(m *Proxy) error {
 	if _, err := io.Copy(p.buf, bytes.NewReader(buf)); err != nil {
 		return errors.Wrap(ErrWriteConn, err)
 	}
+	p.outBytes += uint64(len(buf))
 	// according to the spec, we better flush to avoid server hanging
 	return p.Flush()
 }