diff --git a/examples/metrics/main.go b/examples/metrics/main.go
index 1a69aa545..5e682eb7f 100644
--- a/examples/metrics/main.go
+++ b/examples/metrics/main.go
@@ -3,15 +3,14 @@ package main
 import (
 	"context"
 	"fmt"
+	"log"
+
 	"github.com/go-kratos/kratos/v2/middleware/metrics"
 	prom "github.com/go-kratos/prometheus/metrics"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"log"
 
 	"github.com/go-kratos/kratos/examples/helloworld/helloworld"
 	"github.com/go-kratos/kratos/v2"
-	"github.com/go-kratos/kratos/v2/errors"
-	"github.com/go-kratos/kratos/v2/middleware/recovery"
 	"github.com/go-kratos/kratos/v2/transport/grpc"
 	"github.com/go-kratos/kratos/v2/transport/http"
 	"github.com/prometheus/client_golang/prometheus"
@@ -26,14 +25,16 @@ var (
 
 	_metricSeconds = prometheus.NewHistogramVec(prometheus.HistogramOpts{
 		Namespace: "server",
-		Name:      "request_duration_millisecond",
+		Subsystem: "requests",
+		Name:      "duration_ms",
 		Help:      "server requests duration(ms).",
 		Buckets:   []float64{5, 10, 25, 50, 100, 250, 500, 1000},
 	}, []string{"kind", "operation"})
 
 	_metricRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "client",
-		Name:      "api_requests_total",
+		Subsystem: "requests",
+		Name:      "code_total",
 		Help:      "The total number of processed requests",
 	}, []string{"kind", "operation", "code", "reason"})
 )
@@ -45,12 +46,6 @@ type server struct {
 
 // SayHello implements helloworld.GreeterServer
 func (s *server) SayHello(ctx context.Context, in *helloworld.HelloRequest) (*helloworld.HelloReply, error) {
-	if in.Name == "error" {
-		return nil, errors.BadRequest("custom_error", fmt.Sprintf("invalid argument %s", in.Name))
-	}
-	if in.Name == "panic" {
-		panic("server panic")
-	}
 	return &helloworld.HelloReply{Message: fmt.Sprintf("Hello %+v", in.Name)}, nil
 }
 
@@ -59,16 +54,11 @@ func init() {
 }
 
 func main() {
-	s := &server{}
-
 	grpcSrv := grpc.NewServer(
 		grpc.Address(":9000"),
 		grpc.Middleware(
-			recovery.Recovery(),
 			metrics.Server(
-				metrics.WithSeconds(
-					prom.NewHistogram(_metricSeconds),
-				),
+				metrics.WithSeconds(prom.NewHistogram(_metricSeconds)),
 				metrics.WithRequests(prom.NewCounter(_metricRequests)),
 			),
 		),
@@ -76,18 +66,15 @@ func main() {
 	httpSrv := http.NewServer(
 		http.Address(":8000"),
 		http.Middleware(
-			recovery.Recovery(),
 			metrics.Server(
-				metrics.WithSeconds(
-					prom.NewHistogram(_metricSeconds),
-				),
+				metrics.WithSeconds(prom.NewHistogram(_metricSeconds)),
 				metrics.WithRequests(prom.NewCounter(_metricRequests)),
 			),
 		),
 	)
-
 	httpSrv.Handle("/metrics", promhttp.Handler())
 
+	s := &server{}
 	helloworld.RegisterGreeterServer(grpcSrv, s)
 	helloworld.RegisterGreeterHTTPServer(httpSrv, s)