diff --git a/doc/wiki-cn/warden-resolver.md b/doc/wiki-cn/warden-resolver.md
index 96585f193..0e84a9044 100644
--- a/doc/wiki-cn/warden-resolver.md
+++ b/doc/wiki-cn/warden-resolver.md
@@ -219,6 +219,7 @@ const AppID = "demo.service" // NOTE: example
 func init(){
 	// NOTE: 注意这段代码，表示要使用etcd进行服务发现 ,其他事项参考discovery的说明
     // NOTE: 在启动应用时，可以通过flag(-etcd.endpoints) 或者 环境配置(ETCD_ENDPOINTS)指定etcd节点
+    // NOTE: 如果需要自己指定配置时 需要同时设置DialTimeout 与 DialOptions: []grpc.DialOption{grpc.WithBlock()}
 	resolver.Register(etcd.Builder(nil))
 }
 
diff --git a/go.mod b/go.mod
index 6dc86a6a9..55c580ef5 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/StackExchange/wmi v0.0.0-20190523213609-cbe66965904d // indirect
 	github.com/aristanetworks/goarista v0.0.0-20190712234253-ed1100a1c015 // indirect
 	github.com/coreos/bbolt v1.3.3 // indirect
-	github.com/coreos/etcd v3.3.13+incompatible
+	github.com/coreos/etcd v3.3.13+incompatible // indirect
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f // indirect
 	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
@@ -55,6 +55,7 @@ require (
 	github.com/urfave/cli v1.20.0
 	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
 	go.etcd.io/bbolt v1.3.3 // indirect
+	go.etcd.io/etcd v3.3.13+incompatible
 	go.uber.org/atomic v1.4.0 // indirect
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.10.0 // indirect
diff --git a/go.sum b/go.sum
index 67503c259..b07c65043 100644
--- a/go.sum
+++ b/go.sum
@@ -86,7 +86,6 @@ github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
-github.com/golang/sync v0.0.0-20190427212804-112230192c58 h1:CfvS2lsMxwV6vyyjjeXQ0dqkW/yQ0gyOHG6QNzjOUw0=
 github.com/golang/sync v0.0.0-20190427212804-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 github.com/golang/sys v0.0.0-20190602015325-4c4f7f33c9ed h1:BIG54Uwbp5ZzFl3i2t+d+EGE8jq89zYK7iXM6tyv76E=
 github.com/golang/sys v0.0.0-20190602015325-4c4f7f33c9ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -206,6 +205,8 @@ github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 h1:eY9dn8+vbi4tKz5
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 go.etcd.io/bbolt v1.3.3 h1:MUGmc65QhB3pIlaQ5bB4LwqSj6GIonVJXpZiaKNyaKk=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
+go.etcd.io/etcd v3.3.13+incompatible h1:jCejD5EMnlGxFvcGRyEV4VGlENZc7oPQX6o0t7n3xbw=
+go.etcd.io/etcd v3.3.13+incompatible/go.mod h1:yaeTdrJi5lOmYerz05bd8+V7KubZs8YSFZfzsF9A6aI=
 go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
diff --git a/pkg/naming/etcd/etcd.go b/pkg/naming/etcd/etcd.go
index 338b216eb..241b192f3 100644
--- a/pkg/naming/etcd/etcd.go
+++ b/pkg/naming/etcd/etcd.go
@@ -14,8 +14,9 @@ import (
 
 	"github.com/bilibili/kratos/pkg/log"
 	"github.com/bilibili/kratos/pkg/naming"
-	"github.com/coreos/etcd/clientv3"
-	"github.com/coreos/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"google.golang.org/grpc"
 )
 
 var (
@@ -23,7 +24,9 @@ var (
 	endpoints  string
 	etcdPrefix string
 
-	RegisterTTL = 30
+	//Time units is second
+	registerTTL        = 90
+	defaultDialTimeout = 30
 )
 
 var (
@@ -96,7 +99,8 @@ func New(c *clientv3.Config) (e *EtcdBuilder, err error) {
 		}
 		c = &clientv3.Config{
 			Endpoints:   strings.Split(endpoints, ","),
-			DialTimeout: time.Second * 30,
+			DialTimeout: time.Second * time.Duration(defaultDialTimeout),
+			DialOptions: []grpc.DialOption{grpc.WithBlock()},
 		}
 	}
 	cli, err := clientv3.New(*c)
@@ -179,8 +183,8 @@ func (e *EtcdBuilder) Register(ctx context.Context, ins *naming.Instance) (cance
 	})
 
 	go func() {
-		//提前2秒续约 避免续约操作缓慢时租约过期
-		ticker := time.NewTicker(time.Duration(RegisterTTL-2) * time.Second)
+
+		ticker := time.NewTicker(time.Duration(registerTTL/3) * time.Second)
 		defer ticker.Stop()
 		for {
 			select {
@@ -201,9 +205,9 @@ func (e *EtcdBuilder) register(ctx context.Context, ins *naming.Instance) (err e
 	prefix := e.keyPrefix(ins)
 	val, _ := json.Marshal(ins)
 
-	ttlResp, err := e.cli.Grant(context.TODO(), int64(RegisterTTL))
+	ttlResp, err := e.cli.Grant(context.TODO(), int64(registerTTL))
 	if err != nil {
-		log.Error("etcd: register client.Grant(%v) error(%v)", RegisterTTL, err)
+		log.Error("etcd: register client.Grant(%v) error(%v)", registerTTL, err)
 		return err
 	}
 	_, err = e.cli.Put(ctx, prefix, string(val), clientv3.WithLease(ttlResp.ID))
diff --git a/pkg/naming/etcd/etcd_test.go b/pkg/naming/etcd/etcd_test.go
index 445958725..72d15aa15 100644
--- a/pkg/naming/etcd/etcd_test.go
+++ b/pkg/naming/etcd/etcd_test.go
@@ -3,10 +3,11 @@ package etcd
 import (
 	"context"
 	"fmt"
-	"github.com/bilibili/kratos/pkg/naming"
-	"github.com/coreos/etcd/clientv3"
 	"testing"
 	"time"
+	"github.com/bilibili/kratos/pkg/naming"
+	"go.etcd.io/etcd/clientv3"
+	"google.golang.org/grpc"
 )
 
 func TestNew(t *testing.T) {
@@ -14,6 +15,7 @@ func TestNew(t *testing.T) {
 	config := &clientv3.Config{
 		Endpoints:   []string{"127.0.0.1:2379"},
 		DialTimeout: time.Second * 3,
+		DialOptions: []grpc.DialOption{grpc.WithBlock()},
 	}
 	builder, err := New(config)
 
diff --git a/pkg/net/http/blademaster/metadata.go b/pkg/net/http/blademaster/metadata.go
index 0ce65d102..24139dc35 100644
--- a/pkg/net/http/blademaster/metadata.go
+++ b/pkg/net/http/blademaster/metadata.go
@@ -52,7 +52,7 @@ var _parser = map[string]func(string) interface{}{
 
 func parseMetadataTo(req *http.Request, to metadata.MD) {
 	for rawKey := range req.Header {
-		key := strings.ReplaceAll(strings.TrimLeft(strings.ToLower(rawKey), _httpHeaderMetadata), "-", "_")
+		key := strings.ReplaceAll(strings.TrimPrefix(strings.ToLower(rawKey), _httpHeaderMetadata), "-", "_")
 		rawValue := req.Header.Get(rawKey)
 		var value interface{} = rawValue
 		parser, ok := _parser[key]
diff --git a/pkg/net/netutil/breaker/sre_breaker.go b/pkg/net/netutil/breaker/sre_breaker.go
index 5e410cd98..44ccb4b71 100644
--- a/pkg/net/netutil/breaker/sre_breaker.go
+++ b/pkg/net/netutil/breaker/sre_breaker.go
@@ -3,6 +3,7 @@ package breaker
 import (
 	"math"
 	"math/rand"
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -14,12 +15,14 @@ import (
 // sreBreaker is a sre CircuitBreaker pattern.
 type sreBreaker struct {
 	stat metric.RollingCounter
+	r    *rand.Rand
+	// rand.New(...) returns a non thread safe object
+	randLock sync.Mutex
 
 	k       float64
 	request int64
 
 	state int32
-	r     *rand.Rand
 }
 
 func newSRE(c *Config) Breaker {
@@ -69,14 +72,14 @@ func (b *sreBreaker) Allow() error {
 		atomic.CompareAndSwapInt32(&b.state, StateClosed, StateOpen)
 	}
 	dr := math.Max(0, (float64(total)-k)/float64(total+1))
-	rr := b.r.Float64()
+	drop := b.trueOnProba(dr)
 	if log.V(5) {
-		log.Info("breaker: drop ratio: %f, real rand: %f, drop: %v", dr, rr, dr > rr)
+		log.Info("breaker: drop ratio: %f, drop: %t", dr, drop)
 	}
-	if dr <= rr {
-		return nil
+	if drop {
+		return ecode.ServiceUnavailable
 	}
-	return ecode.ServiceUnavailable
+	return nil
 }
 
 func (b *sreBreaker) MarkSuccess() {
@@ -88,3 +91,10 @@ func (b *sreBreaker) MarkFailed() {
 	// drop ratio higher.
 	b.stat.Add(0)
 }
+
+func (b *sreBreaker) trueOnProba(proba float64) (truth bool) {
+	b.randLock.Lock()
+	truth = b.r.Float64() < proba
+	b.randLock.Unlock()
+	return
+}
diff --git a/pkg/net/netutil/breaker/sre_breaker_test.go b/pkg/net/netutil/breaker/sre_breaker_test.go
index 4559c4fc5..9df374736 100644
--- a/pkg/net/netutil/breaker/sre_breaker_test.go
+++ b/pkg/net/netutil/breaker/sre_breaker_test.go
@@ -5,7 +5,7 @@ import (
 	"math/rand"
 	"testing"
 	"time"
-	
+
 	"github.com/bilibili/kratos/pkg/stat/metric"
 	xtime "github.com/bilibili/kratos/pkg/time"
 
@@ -147,6 +147,22 @@ func TestSRESummary(t *testing.T) {
 	})
 }
 
+func TestTrueOnProba(t *testing.T) {
+	const proba = math.Pi / 10
+	const total = 100000
+	const epsilon = 0.05
+	var count int
+	b := getSREBreaker()
+	for i := 0; i < total; i++ {
+		if b.trueOnProba(proba) {
+			count++
+		}
+	}
+
+	ratio := float64(count) / float64(total)
+	assert.InEpsilon(t, proba, ratio, epsilon)
+}
+
 func BenchmarkSreBreakerAllow(b *testing.B) {
 	breaker := getSRE()
 	b.ResetTimer()
diff --git a/pkg/net/rpc/warden/client.go b/pkg/net/rpc/warden/client.go
index ac1ba130b..f8ae1d2b8 100644
--- a/pkg/net/rpc/warden/client.go
+++ b/pkg/net/rpc/warden/client.go
@@ -3,6 +3,8 @@ package warden
 import (
 	"context"
 	"fmt"
+	"github.com/bilibili/kratos/pkg/net/rpc/warden/resolver"
+	"github.com/bilibili/kratos/pkg/net/rpc/warden/resolver/direct"
 	"net/url"
 	"os"
 	"strconv"
@@ -51,6 +53,11 @@ func baseMetadata() metadata.MD {
 	return gmd
 }
 
+// Register direct resolver by default to handle direct:// scheme.
+func init() {
+	resolver.Register(direct.New())
+}
+
 // ClientConfig is rpc client conf.
 type ClientConfig struct {
 	Dial                   xtime.Duration