Merge pull request 'database: add FormatDSN' (#278) from database-newv3 into v3

Reviewed-on: #278

README.md

@@ -1,4 +1,4 @@
-# Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/go.unistack.org/micro/v4?tab=overview) [![Status](https://github.com/unistack-org/micro/workflows/build/badge.svg?branch=master)](https://github.com/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Amaster+event%3Apush) [![Lint](https://goreportcard.com/badge/go.unistack.org/micro/v4)](https://goreportcard.com/report/go.unistack.org/micro/v4) [![Coverage](https://codecov.io/gh/unistack-org/micro/branch/v4/graph/badge.svg?token=OZPO2LP7VS)](https://codecov.io/gh/unistack-org/micro)
+# Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/unistack-org/micro/v3?tab=overview) [![Status](https://github.com/unistack-org/micro/workflows/build/badge.svg?branch=master)](https://github.com/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Amaster+event%3Apush) [![Lint](https://goreportcard.com/badge/go.unistack.org/micro/v3)](https://goreportcard.com/report/go.unistack.org/micro/v3) [![Coverage](https://codecov.io/gh/unistack-org/micro/branch/v3/graph/badge.svg?token=OZPO2LP7VS)](https://codecov.io/gh/unistack-org/micro)
 
 Micro is a standard library for microservices.
 

broker/broker.go

@@ -1,12 +1,12 @@
 // Package broker is an interface used for asynchronous messaging
-package broker // import "go.unistack.org/micro/v4/broker"
+package broker // import "go.unistack.org/micro/v3/broker"
 
 import (
 	"context"
 	"errors"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 // DefaultBroker default memory broker

broker/memory.go

@@ -3,14 +3,13 @@ package broker
 import (
 	"context"
 	"sync"
-	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	maddr "go.unistack.org/micro/v4/util/addr"
-	"go.unistack.org/micro/v4/util/id"
-	mnet "go.unistack.org/micro/v4/util/net"
-	"go.unistack.org/micro/v4/util/rand"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	maddr "go.unistack.org/micro/v3/util/addr"
+	"go.unistack.org/micro/v3/util/id"
+	mnet "go.unistack.org/micro/v3/util/net"
+	"go.unistack.org/micro/v3/util/rand"
 )
 
 type memoryBroker struct {
@@ -135,22 +134,13 @@ func (m *memoryBroker) publish(ctx context.Context, msgs []*Message, opts ...Pub
 		eh := m.opts.ErrorHandler
 
 		for t, ms := range msgTopicMap {
-			ts := time.Now()
-
-			m.opts.Meter.Counter(PublishMessageInflight, "endpoint", t).Add(len(ms))
-			m.opts.Meter.Counter(SubscribeMessageInflight, "endpoint", t).Add(len(ms))
-
 			m.RLock()
 			subs, ok := m.subscribers[t]
 			m.RUnlock()
 			if !ok {
-				m.opts.Meter.Counter(PublishMessageTotal, "endpoint", t, "status", "failure").Add(len(ms))
-				m.opts.Meter.Counter(PublishMessageInflight, "endpoint", t).Add(-len(ms))
-				m.opts.Meter.Counter(SubscribeMessageInflight, "endpoint", t).Add(-len(ms))
 				continue
 			}
 
-			m.opts.Meter.Counter(PublishMessageTotal, "endpoint", t, "status", "success").Add(len(ms))
 			for _, sub := range subs {
 				if sub.opts.BatchErrorHandler != nil {
 					beh = sub.opts.BatchErrorHandler
@@ -162,65 +152,37 @@ func (m *memoryBroker) publish(ctx context.Context, msgs []*Message, opts ...Pub
 				switch {
 				// batch processing
 				case sub.batchhandler != nil:
-
 					if err = sub.batchhandler(ms); err != nil {
-						m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "failure").Inc()
 						ms.SetError(err)
 						if beh != nil {
 							_ = beh(ms)
 						} else if m.opts.Logger.V(logger.ErrorLevel) {
 							m.opts.Logger.Error(m.opts.Context, err.Error())
 						}
-					} else {
-						if sub.opts.AutoAck {
-							if err = ms.Ack(); err != nil {
-								m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
-								m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "failure").Inc()
-							} else {
-								m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "success").Inc()
-							}
-						} else {
-							m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "success").Inc()
+					} else if sub.opts.AutoAck {
+						if err = ms.Ack(); err != nil {
+							m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
 						}
 					}
-					m.opts.Meter.Counter(PublishMessageInflight, "endpoint", t).Add(-len(ms))
-					m.opts.Meter.Counter(SubscribeMessageInflight, "endpoint", t).Add(-len(ms))
 					// single processing
 				case sub.handler != nil:
 					for _, p := range ms {
 						if err = sub.handler(p); err != nil {
-							m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "failure").Inc()
 							p.SetError(err)
 							if eh != nil {
 								_ = eh(p)
 							} else if m.opts.Logger.V(logger.ErrorLevel) {
 								m.opts.Logger.Error(m.opts.Context, err.Error())
 							}
-						} else {
-							if sub.opts.AutoAck {
-								if err = p.Ack(); err != nil {
-									m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
-									m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "failure").Inc()
-								} else {
-									m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "success").Inc()
-								}
-							} else {
-								m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "success").Inc()
+						} else if sub.opts.AutoAck {
+							if err = p.Ack(); err != nil {
+								m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
 							}
 						}
-						m.opts.Meter.Counter(PublishMessageInflight, "endpoint", t).Add(-1)
-						m.opts.Meter.Counter(SubscribeMessageInflight, "endpoint", t).Add(-1)
 					}
 				}
-
 			}
-			te := time.Since(ts)
-			m.opts.Meter.Summary(PublishMessageLatencyMicroseconds, "endpoint", t).Update(te.Seconds())
-			m.opts.Meter.Histogram(PublishMessageDurationSeconds, "endpoint", t).Update(te.Seconds())
-			m.opts.Meter.Summary(SubscribeMessageLatencyMicroseconds, "endpoint", t).Update(te.Seconds())
-			m.opts.Meter.Histogram(SubscribeMessageDurationSeconds, "endpoint", t).Update(te.Seconds())
 		}
-
 	}
 
 	return nil

broker/memory_test.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 func TestMemoryBatchBroker(t *testing.T) {

broker/options.go

@@ -5,30 +5,11 @@ import (
 	"crypto/tls"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/tracer"
-)
-
-var (
-	// PublishMessageDurationSeconds specifies meter metric name
-	PublishMessageDurationSeconds = "publish_message_duration_seconds"
-	// PublishMessageLatencyMicroseconds specifies meter metric name
-	PublishMessageLatencyMicroseconds = "publish_message_latency_microseconds"
-	// PublishMessageTotal specifies meter metric name
-	PublishMessageTotal = "publish_message_total"
-	// PublishMessageInflight specifies meter metric name
-	PublishMessageInflight = "publish_message_inflight"
-	// SubscribeMessageDurationSeconds specifies meter metric name
-	SubscribeMessageDurationSeconds = "subscribe_message_duration_seconds"
-	// SubscribeMessageLatencyMicroseconds specifies meter metric name
-	SubscribeMessageLatencyMicroseconds = "subscribe_message_latency_microseconds"
-	// SubscribeMessageTotal specifies meter metric name
-	SubscribeMessageTotal = "subscribe_message_total"
-	// SubscribeMessageInflight specifies meter metric name
-	SubscribeMessageInflight = "subscribe_message_inflight"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options struct

client/backoff.go

@@ -5,7 +5,7 @@ import (
 	"math"
 	"time"
 
-	"go.unistack.org/micro/v4/util/backoff"
+	"go.unistack.org/micro/v3/util/backoff"
 )
 
 // BackoffFunc is the backoff call func

client/client.go

@@ -1,12 +1,12 @@
 // Package client is an interface for an RPC client
-package client // import "go.unistack.org/micro/v4/client"
+package client // import "go.unistack.org/micro/v3/client"
 
 import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (

client/lookup.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"sort"
 
-	"go.unistack.org/micro/v4/errors"
-	"go.unistack.org/micro/v4/router"
+	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v3/router"
 )
 
 // LookupFunc is used to lookup routes for a service

client/noop.go

@@ -5,11 +5,11 @@ import (
 	"fmt"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/errors"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/selector"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/selector"
 )
 
 // DefaultCodecs will be used to encode/decode data
@@ -490,6 +490,13 @@ func (n *noopClient) publish(ctx context.Context, ps []Message, opts ...PublishO
 		if !ok {
 			md = metadata.New(0)
 		}
+
+		iter := p.Metadata().Iterator()
+		var k, v string
+		for iter.Next(&k, &v) {
+			md.Set(k, v)
+		}
+
 		md[metadata.HeaderContentType] = p.ContentType()
 
 		topic := p.Topic()

client/options.go

@@ -6,17 +6,17 @@ import (
 	"net"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v4/selector/random"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v3/selector/random"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options holds client options

client/retry.go

@@ -3,7 +3,7 @@ package client
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v3/errors"
 )
 
 // RetryFunc that returning either false or a non-nil error will result in the call not being retried

client/retry_test.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v3/errors"
 )
 
 func TestRetryAlways(t *testing.T) {

client/test_request.go

@@ -1,7 +1,7 @@
 package client
 
 import (
-	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v3/codec"
 )
 
 type testRequest struct {

codec/codec.go

@@ -1,11 +1,11 @@
 // Package codec is an interface for encoding messages
-package codec // import "go.unistack.org/micro/v4/codec"
+package codec // import "go.unistack.org/micro/v3/codec"
 
 import (
 	"errors"
 	"io"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 // Message types

codec/frame.proto

@@ -1,4 +1,4 @@
-// Copyright 2021-2023 Unistack LLC
+// Copyright 2021 Unistack LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.codec;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v4/codec;codec";
+option go_package = "go.unistack.org/micro/v3/codec;codec";
 option java_multiple_files = true;
 option java_outer_classname = "MicroCodec";
 option java_package = "micro.codec";

codec/options.go

@@ -3,9 +3,9 @@ package codec
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Option func

config/config.go

@@ -1,5 +1,5 @@
 // Package config is an interface for dynamic configuration.
-package config // import "go.unistack.org/micro/v4/config"
+package config // import "go.unistack.org/micro/v3/config"
 
 import (
 	"context"

config/default.go

@@ -7,9 +7,11 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/imdario/mergo"
-	rutil "go.unistack.org/micro/v4/util/reflect"
-	mtime "go.unistack.org/micro/v4/util/time"
+	mid "go.unistack.org/micro/v3/util/id"
+	rutil "go.unistack.org/micro/v3/util/reflect"
+	mtime "go.unistack.org/micro/v3/util/time"
 )
 
 type defaultConfig struct {
@@ -124,6 +126,20 @@ func fillValue(value reflect.Value, val string) error {
 		}
 		value.Set(reflect.ValueOf(v))
 	case reflect.String:
+		switch val {
+		case "micro:generate uuid":
+			uid, err := uuid.NewRandom()
+			if err != nil {
+				return err
+			}
+			val = uid.String()
+		case "micro:generate id":
+			uid, err := mid.New()
+			if err != nil {
+				return err
+			}
+			val = uid
+		}
 		value.Set(reflect.ValueOf(val))
 	case reflect.Float32:
 		v, err := strconv.ParseFloat(val, 32)
@@ -169,7 +185,7 @@ func fillValue(value reflect.Value, val string) error {
 				return err
 			}
 			value.Set(reflect.ValueOf(v))
-		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "go.unistack.org/micro/v4/util/time":
+		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "go.unistack.org/micro/v3/util/time":
 			v, err := mtime.ParseDuration(val)
 			if err != nil {
 				return err

config/default_test.go

@@ -6,17 +6,21 @@ import (
 	"testing"
 	"time"
 
-	"go.unistack.org/micro/v4/config"
-	mtime "go.unistack.org/micro/v4/util/time"
+	"go.unistack.org/micro/v3/config"
+	mid "go.unistack.org/micro/v3/util/id"
+	mtime "go.unistack.org/micro/v3/util/time"
 )
 
 type cfg struct {
 	StringValue    string `default:"string_value"`
 	IgnoreValue    string `json:"-"`
 	StructValue    *cfgStructValue
-	IntValue       int            `default:"99"`
-	DurationValue  time.Duration  `default:"10s"`
-	MDurationValue mtime.Duration `default:"10s"`
+	IntValue       int             `default:"99"`
+	DurationValue  time.Duration   `default:"10s"`
+	MDurationValue mtime.Duration  `default:"10s"`
+	MapValue       map[string]bool `default:"key1=true,key2=false"`
+	UUIDValue      string          `default:"micro:generate uuid"`
+	IDValue        string          `default:"micro:generate id"`
 }
 
 type cfgStructValue struct {
@@ -67,6 +71,21 @@ func TestDefault(t *testing.T) {
 	if conf.StringValue != "after_load" {
 		t.Fatal("AfterLoad option not working")
 	}
+	if len(conf.MapValue) != 2 {
+		t.Fatalf("map value invalid: %#+v\n", conf.MapValue)
+	}
+
+	if conf.UUIDValue == "" {
+		t.Fatalf("uuid value empty")
+	} else if len(conf.UUIDValue) != 36 {
+		t.Fatalf("uuid value invalid: %s", conf.UUIDValue)
+	}
+
+	if conf.IDValue == "" {
+		t.Fatalf("id value empty")
+	} else if len(conf.IDValue) != mid.DefaultSize {
+		t.Fatalf("id value invalid: %s", conf.IDValue)
+	}
 	_ = conf
 	// t.Logf("%#+v\n", conf)
 }

config/options.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options hold the config options

database/dsn.go

@@ -0,0 +1,157 @@
+package database
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+var (
+	ErrInvalidDSNAddr      = errors.New("invalid dsn addr")
+	ErrInvalidDSNUnescaped = errors.New("dsn must be escaped")
+	ErrInvalidDSNNoSlash   = errors.New("dsn must contains slash")
+)
+
+type Config struct {
+	TLSConfig *tls.Config
+	Username  string
+	Password  string
+	Scheme    string
+	Host      string
+	Port      string
+	Database  string
+	Params    []string
+}
+
+func (cfg *Config) FormatDSN() string {
+	var s strings.Builder
+
+	if len(cfg.Scheme) > 0 {
+		s.WriteString(cfg.Scheme + "://")
+	}
+	// [username[:password]@]
+	if len(cfg.Username) > 0 {
+		s.WriteString(cfg.Username)
+		if len(cfg.Password) > 0 {
+			s.WriteByte(':')
+			s.WriteString(url.PathEscape(cfg.Password))
+		}
+		s.WriteByte('@')
+	}
+
+	// [host:port]
+	if len(cfg.Host) > 0 {
+		s.WriteString(cfg.Host)
+		if len(cfg.Port) > 0 {
+			s.WriteByte(':')
+			s.WriteString(cfg.Port)
+		}
+	}
+
+	// /dbname
+	s.WriteByte('/')
+	s.WriteString(url.PathEscape(cfg.Database))
+
+	for i := 0; i < len(cfg.Params); i += 2 {
+		if i == 0 {
+			s.WriteString("?")
+		} else {
+			s.WriteString("&")
+		}
+		s.WriteString(cfg.Params[i])
+		s.WriteString("=")
+		s.WriteString(cfg.Params[i+1])
+	}
+
+	return s.String()
+}
+
+func ParseDSN(dsn string) (*Config, error) {
+	cfg := &Config{}
+
+	// [user[:password]@][net[(addr)]]/dbname[?param1=value1&paramN=valueN]
+	// Find last '/' that goes before dbname
+	foundSlash := false
+	for i := len(dsn) - 1; i >= 0; i-- {
+		if dsn[i] == '/' {
+			foundSlash = true
+			var j, k int
+
+			// left part is empty if i <= 0
+			if i > 0 {
+				// Find the first ':' in dsn
+				for j = i; j >= 0; j-- {
+					if dsn[j] == ':' {
+						cfg.Scheme = dsn[0:j]
+					}
+				}
+
+				// [username[:password]@][host]
+				// Find the last '@' in dsn[:i]
+				for j = i; j >= 0; j-- {
+					if dsn[j] == '@' {
+						// username[:password]
+						// Find the second ':' in dsn[:j]
+						for k = 0; k < j; k++ {
+							if dsn[k] == ':' {
+								if cfg.Scheme == dsn[:k] {
+									continue
+								}
+								var err error
+								cfg.Password, err = url.PathUnescape(dsn[k+1 : j])
+								if err != nil {
+									return nil, err
+								}
+								break
+							}
+						}
+						cfg.Username = dsn[len(cfg.Scheme)+3 : k]
+						break
+					}
+				}
+
+				for k = j + 1; k < i; k++ {
+					if dsn[k] == ':' {
+						cfg.Host = dsn[j+1 : k]
+						cfg.Port = dsn[k+1 : i]
+						break
+					}
+				}
+
+			}
+
+			// dbname[?param1=value1&...&paramN=valueN]
+			// Find the first '?' in dsn[i+1:]
+			for j = i + 1; j < len(dsn); j++ {
+				if dsn[j] == '?' {
+					parts := strings.Split(dsn[j+1:], "&")
+					cfg.Params = make([]string, 0, len(parts)*2)
+					for _, p := range parts {
+						k, v, found := strings.Cut(p, "=")
+						if !found {
+							continue
+						}
+						cfg.Params = append(cfg.Params, k, v)
+					}
+
+					break
+				}
+			}
+			var err error
+			dbname := dsn[i+1 : j]
+			if cfg.Database, err = url.PathUnescape(dbname); err != nil {
+				return nil, fmt.Errorf("invalid dbname %q: %w", dbname, err)
+			}
+
+			break
+		}
+	}
+
+	if !foundSlash && len(dsn) > 0 {
+		return nil, ErrInvalidDSNNoSlash
+	}
+
+	return cfg, nil
+}

database/dsn_test.go

@@ -0,0 +1,31 @@
+package database
+
+import (
+	"net/url"
+	"testing"
+)
+
+func TestParseDSN(t *testing.T) {
+	cfg, err := ParseDSN("postgres://username:p@ssword#@host:12345/dbname?key1=val2&key2=val2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Password != "p@ssword#" {
+		t.Fatalf("parsing error")
+	}
+}
+
+func TestFormatDSN(t *testing.T) {
+	src := "postgres://username:p@ssword#@host:12345/dbname?key1=val2&key2=val2"
+	cfg, err := ParseDSN(src)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dst, err := url.PathUnescape(cfg.FormatDSN())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if src != dst {
+		t.Fatalf("\n%s\n%s", src, dst)
+	}
+}

errors/errors.go

@@ -1,14 +1,20 @@
 // Package errors provides a way to return detailed information
 // for an RPC request error. The error is normally JSON encoded.
-package errors // import "go.unistack.org/micro/v4/errors"
+package errors // import "go.unistack.org/micro/v3/errors"
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"strconv"
 	"strings"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 var (
@@ -340,3 +346,135 @@ func addslashes(str string) string {
 	}
 	return buf.String()
 }
+
+type retryableError struct {
+	err error
+}
+
+// Retryable returns error that can be retried later
+func Retryable(err error) error {
+	return &retryableError{err: err}
+}
+
+type IsRetryableFunc func(error) bool
+
+var (
+	RetrayableOracleErrors = []IsRetryableFunc{
+		func(err error) bool {
+			errmsg := err.Error()
+			switch {
+			case strings.Contains(errmsg, `ORA-`):
+				return true
+			case strings.Contains(errmsg, `can not assign`):
+				return true
+			case strings.Contains(errmsg, `can't assign`):
+				return true
+			}
+			return false
+		},
+	}
+	RetrayablePostgresErrors = []IsRetryableFunc{
+		func(err error) bool {
+			errmsg := err.Error()
+			switch {
+			case strings.Contains(errmsg, `number of field descriptions must equal number of`):
+				return true
+			case strings.Contains(errmsg, `not a pointer`):
+				return true
+			case strings.Contains(errmsg, `values, but dst struct has only`):
+				return true
+			case strings.Contains(errmsg, `struct doesn't have corresponding row field`):
+				return true
+			case strings.Contains(errmsg, `cannot find field`):
+				return true
+			case strings.Contains(errmsg, `cannot scan`) || strings.Contains(errmsg, `cannot convert`):
+				return true
+			case strings.Contains(errmsg, `failed to connect to`):
+				return true
+			}
+			return false
+		},
+	}
+	RetryableMicroErrors = []IsRetryableFunc{
+		func(err error) bool {
+			switch verr := err.(type) {
+			case *Error:
+				switch verr.Code {
+				case 401, 403, 408, 500, 501, 502, 503, 504:
+					return true
+				default:
+					return false
+				}
+			case *retryableError:
+				return true
+			}
+			return false
+		},
+	}
+	RetryableGoErrors = []IsRetryableFunc{
+		func(err error) bool {
+			switch verr := err.(type) {
+			case interface{ SafeToRetry() bool }:
+				return verr.SafeToRetry()
+			case interface{ Timeout() bool }:
+				return verr.Timeout()
+			}
+			switch {
+			case errors.Is(err, io.EOF), errors.Is(err, io.ErrUnexpectedEOF):
+				return true
+			case errors.Is(err, context.DeadlineExceeded):
+				return true
+			case errors.Is(err, io.ErrClosedPipe), errors.Is(err, io.ErrShortBuffer), errors.Is(err, io.ErrShortWrite):
+				return true
+			}
+			return false
+		},
+	}
+	RetryableGrpcErrors = []IsRetryableFunc{
+		func(err error) bool {
+			st, ok := status.FromError(err)
+			if !ok {
+				return false
+			}
+			switch st.Code() {
+			case codes.Unavailable, codes.ResourceExhausted:
+				return true
+			case codes.DeadlineExceeded:
+				return true
+			case codes.Internal:
+				switch {
+				case strings.Contains(st.Message(), `transport: received the unexpected content-type "text/html; charset=UTF-8"`):
+					return true
+				case strings.Contains(st.Message(), io.ErrUnexpectedEOF.Error()):
+					return true
+				case strings.Contains(st.Message(), `stream terminated by RST_STREAM with error code: INTERNAL_ERROR`):
+					return true
+				}
+			}
+			return false
+		},
+	}
+)
+
+// Unwrap provides error wrapping
+func (e *retryableError) Unwrap() error {
+	return e.err
+}
+
+// Error returns the error string
+func (e *retryableError) Error() string {
+	if e.err == nil {
+		return ""
+	}
+	return e.err.Error()
+}
+
+// IsRetryable checks error for ability to retry later
+func IsRetryable(err error, fns ...IsRetryableFunc) bool {
+	for _, fn := range fns {
+		if ok := fn(err); ok {
+			return true
+		}
+	}
+	return false
+}

errors/errors.proto

@@ -1,4 +1,4 @@
-// Copyright 2021-2023 Unistack LLC
+// Copyright 2021 Unistack LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.errors;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v4/errors;errors";
+option go_package = "go.unistack.org/micro/v3/errors;errors";
 option java_multiple_files = true;
 option java_outer_classname = "MicroErrors";
 option java_package = "micro.errors";

errors/errors_test.go

@@ -8,6 +8,13 @@ import (
 	"testing"
 )
 
+func TestIsRetrayable(t *testing.T) {
+	err := fmt.Errorf("ORA-")
+	if !IsRetryable(err, RetrayableOracleErrors...) {
+		t.Fatalf("IsRetrayable not works")
+	}
+}
+
 func TestMarshalJSON(t *testing.T) {
 	e := InternalServerError("id", "err: %v", fmt.Errorf("err: %v", `xxx: "UNIX_TIMESTAMP": invalid identifier`))
 	_, err := json.Marshal(e)

event.go

@@ -3,7 +3,7 @@ package micro
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v3/client"
 )
 
 // Event is used to publish messages to a topic

flow/default.go

@@ -6,12 +6,12 @@ import (
 	"sync"
 
 	"github.com/silas/dag"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 type microFlow struct {

flow/flow.go

@@ -1,5 +1,5 @@
 // Package flow is an interface used for saga pattern microservice workflow
-package flow // import "go.unistack.org/micro/v4/flow"
+package flow // import "go.unistack.org/micro/v3/flow"
 
 import (
 	"context"
@@ -7,7 +7,7 @@ import (
 	"sync"
 	"sync/atomic"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (

flow/options.go

@@ -4,11 +4,11 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Option func

fsm/fsm.go

@@ -1,4 +1,4 @@
-package fsm // import "go.unistack.org/micro/v4/fsm"
+package fsm // import "go.unistack.org/micro/v3/fsm"
 
 import (
 	"context"

fsm/fsm_test.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v3/logger"
 )
 
 func TestFSMStart(t *testing.T) {

go.mod

@@ -1,10 +1,20 @@
-module go.unistack.org/micro/v4
+module go.unistack.org/micro/v3
 
-go 1.20
+go 1.19
 
 require (
 	github.com/DATA-DOG/go-sqlmock v1.5.0
-	github.com/imdario/mergo v0.3.14
+	github.com/google/uuid v1.3.0
+	github.com/imdario/mergo v0.3.15
 	github.com/patrickmn/go-cache v2.1.0+incompatible
-	github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35
+	github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5
+	golang.org/x/sync v0.3.0
+	google.golang.org/grpc v1.57.0
+	google.golang.org/protobuf v1.31.0
+)
+
+require (
+	github.com/golang/protobuf v1.5.3 // indirect
+	golang.org/x/net v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230526203410-71b5a4ffd15e // indirect
 )

go.sum

@@ -1,11 +1,33 @@
 github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20OEh60=
 github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
-github.com/imdario/mergo v0.3.14 h1:fOqeC1+nCuuk6PKQdg9YmosXX7Y7mHX6R/0ZldI9iHo=
-github.com/imdario/mergo v0.3.14/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/imdario/mergo v0.3.15 h1:M8XP7IuFNsqUx6VPK2P9OSmsYsI/YFaGil0uD21V3dM=
+github.com/imdario/mergo v0.3.15/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
-github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35 h1:4mohWoM/UGg1BvFFiqSPRl5uwJY3rVV0HQX0ETqauqQ=
-github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
+github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5 h1:G/FZtUu7a6NTWl3KUHMV9jkLAh/Rvtf03NWMHaEDl+E=
+github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
+golang.org/x/net v0.14.0 h1:BONx9s002vGdD9umnlX1Po8vOZmrgH34qlHcD1MfK14=
+golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
+golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20230526203410-71b5a4ffd15e h1:NumxXLPfHSndr3wBBdeKiVHjGVFzi9RX2HwwQke94iY=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20230526203410-71b5a4ffd15e/go.mod h1:66JfowdXAEgad5O9NnYcsNPLCPZJD++2L9X0PCMODrA=
+google.golang.org/grpc v1.57.0 h1:kfzNeI/klCGD2YPMUlaGNT3pxvYfga7smW3Vth8Zsiw=
+google.golang.org/grpc v1.57.0/go.mod h1:Sd+9RMTACXwmub0zcNY2c4arhtrbBYD1AUHI/dt16Mo=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

logger/logger.go

@@ -1,5 +1,5 @@
 // Package logger provides a log interface
-package logger // import "go.unistack.org/micro/v4/logger"
+package logger // import "go.unistack.org/micro/v3/logger"
 
 import (
 	"context"

logger/unwrap/unwrap.go

@@ -8,7 +8,7 @@ import (
 	"strconv"
 	"strings"
 
-	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v3/codec"
 )
 
 const sf = "0-+# "

logger/unwrap/unwrap_test.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"testing"
 
-	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v3/codec"
 )
 
 func TestUnwrap(t *testing.T) {

logger/wrapper/wrapper.go

@@ -5,9 +5,9 @@ import (
 	"context"
 	"fmt"
 
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/server"
 )
 
 var (

metadata/context.go

@@ -39,8 +39,6 @@ func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
 
 // FromContext returns metadata from the given context
 // returned metadata shoud not be modified or race condition happens
-//
-// Deprecated: use FromIncomingContext or FromOutgoingContext
 func FromContext(ctx context.Context) (Metadata, bool) {
 	if ctx == nil {
 		return nil, false
@@ -53,8 +51,6 @@ func FromContext(ctx context.Context) (Metadata, bool) {
 }
 
 // NewContext creates a new context with the given metadata
-//
-// Deprecated: use NewIncomingContext or NewOutgoingContext
 func NewContext(ctx context.Context, md Metadata) context.Context {
 	if ctx == nil {
 		ctx = context.Background()

metadata/metadata.go

@@ -1,5 +1,5 @@
 // Package metadata is a way of defining message headers
-package metadata // import "go.unistack.org/micro/v4/metadata"
+package metadata // import "go.unistack.org/micro/v3/metadata"
 
 import (
 	"net/textproto"
@@ -19,6 +19,8 @@ var (
 	HeaderTimeout = "Micro-Timeout"
 	// HeaderAuthorization specifies Authorization header
 	HeaderAuthorization = "Authorization"
+	// HeaderXRequestID specifies request id
+	HeaderXRequestID = "X-Request-Id"
 )
 
 // Metadata is our way of representing request headers internally.

meter/meter.go

@@ -1,5 +1,5 @@
 // Package meter is for instrumentation
-package meter // import "go.unistack.org/micro/v4/meter"
+package meter // import "go.unistack.org/micro/v3/meter"
 
 import (
 	"io"

meter/options.go

@@ -3,7 +3,7 @@ package meter
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v3/logger"
 )
 
 // Option powers the configuration for metrics implementations:

meter/wrapper/wrapper.go

@@ -1,13 +1,13 @@
-package wrapper // import "go.unistack.org/micro/v4/meter/wrapper"
+package wrapper // import "go.unistack.org/micro/v3/meter/wrapper"
 
 import (
 	"context"
 	"fmt"
 	"time"
 
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/server"
 )
 
 var (
@@ -27,6 +27,22 @@ var (
 	ServerRequestTotal = "server_request_total"
 	// ServerRequestInflight specifies meter metric name
 	ServerRequestInflight = "server_request_inflight"
+	// PublishMessageDurationSeconds specifies meter metric name
+	PublishMessageDurationSeconds = "publish_message_duration_seconds"
+	// PublishMessageLatencyMicroseconds specifies meter metric name
+	PublishMessageLatencyMicroseconds = "publish_message_latency_microseconds"
+	// PublishMessageTotal specifies meter metric name
+	PublishMessageTotal = "publish_message_total"
+	// PublishMessageInflight specifies meter metric name
+	PublishMessageInflight = "publish_message_inflight"
+	// SubscribeMessageDurationSeconds specifies meter metric name
+	SubscribeMessageDurationSeconds = "subscribe_message_duration_seconds"
+	// SubscribeMessageLatencyMicroseconds specifies meter metric name
+	SubscribeMessageLatencyMicroseconds = "subscribe_message_latency_microseconds"
+	// SubscribeMessageTotal specifies meter metric name
+	SubscribeMessageTotal = "subscribe_message_total"
+	// SubscribeMessageInflight specifies meter metric name
+	SubscribeMessageInflight = "subscribe_message_inflight"
 
 	labelSuccess  = "success"
 	labelFailure  = "failure"
@@ -214,7 +230,37 @@ func (w *wrapper) Stream(ctx context.Context, req client.Request, opts ...client
 }
 
 func (w *wrapper) Publish(ctx context.Context, p client.Message, opts ...client.PublishOption) error {
-	return w.Client.Publish(ctx, p, opts...)
+	endpoint := p.Topic()
+
+	labels := make([]string, 0, 4)
+	labels = append(labels, labelEndpoint, endpoint)
+
+	w.opts.Meter.Counter(PublishMessageInflight, labels...).Inc()
+	ts := time.Now()
+	err := w.Client.Publish(ctx, p, opts...)
+	te := time.Since(ts)
+	w.opts.Meter.Counter(PublishMessageInflight, labels...).Dec()
+
+	w.opts.Meter.Summary(PublishMessageLatencyMicroseconds, labels...).Update(te.Seconds())
+	w.opts.Meter.Histogram(PublishMessageDurationSeconds, labels...).Update(te.Seconds())
+
+	if err == nil {
+		labels = append(labels, labelStatus, labelSuccess)
+	} else {
+		labels = append(labels, labelStatus, labelFailure)
+	}
+	w.opts.Meter.Counter(PublishMessageTotal, labels...).Inc()
+
+	return err
+}
+
+// NewHandlerWrapper create new server handler wrapper
+// deprecated
+func NewHandlerWrapper(opts ...Option) server.HandlerWrapper {
+	handler := &wrapper{
+		opts: NewOptions(opts...),
+	}
+	return handler.HandlerFunc
 }
 
 // NewServerHandlerWrapper create new server handler wrapper
@@ -256,3 +302,46 @@ func (w *wrapper) HandlerFunc(fn server.HandlerFunc) server.HandlerFunc {
 		return err
 	}
 }
+
+// NewSubscriberWrapper create server subscribe wrapper
+// deprecated
+func NewSubscriberWrapper(opts ...Option) server.SubscriberWrapper {
+	handler := &wrapper{
+		opts: NewOptions(opts...),
+	}
+	return handler.SubscriberFunc
+}
+
+func NewServerSubscriberWrapper(opts ...Option) server.SubscriberWrapper {
+	handler := &wrapper{
+		opts: NewOptions(opts...),
+	}
+	return handler.SubscriberFunc
+}
+
+func (w *wrapper) SubscriberFunc(fn server.SubscriberFunc) server.SubscriberFunc {
+	return func(ctx context.Context, msg server.Message) error {
+		endpoint := msg.Topic()
+
+		labels := make([]string, 0, 4)
+		labels = append(labels, labelEndpoint, endpoint)
+
+		w.opts.Meter.Counter(SubscribeMessageInflight, labels...).Inc()
+		ts := time.Now()
+		err := fn(ctx, msg)
+		te := time.Since(ts)
+		w.opts.Meter.Counter(SubscribeMessageInflight, labels...).Dec()
+
+		w.opts.Meter.Summary(SubscribeMessageLatencyMicroseconds, labels...).Update(te.Seconds())
+		w.opts.Meter.Histogram(SubscribeMessageDurationSeconds, labels...).Update(te.Seconds())
+
+		if err == nil {
+			labels = append(labels, labelStatus, labelSuccess)
+		} else {
+			labels = append(labels, labelStatus, labelFailure)
+		}
+		w.opts.Meter.Counter(SubscribeMessageTotal, labels...).Inc()
+
+		return err
+	}
+}

mtls/mtls.go

@@ -1,4 +1,4 @@
-package mtls // import "go.unistack.org/micro/v4/mtls"
+package mtls // import "go.unistack.org/micro/v3/mtls"
 
 import (
 	"bytes"

network/network.go

@@ -1,9 +1,9 @@
 // Package network is for creating internetworks
-package network // import "go.unistack.org/micro/v4/network"
+package network // import "go.unistack.org/micro/v3/network"
 
 import (
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/server"
 )
 
 // Error is network node errors

network/options.go

@@ -1,13 +1,13 @@
 package network
 
 import (
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/tunnel"
-	"go.unistack.org/micro/v4/proxy"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/network/tunnel"
+	"go.unistack.org/micro/v3/proxy"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 // Option func

network/transport/memory.go

@@ -8,9 +8,9 @@ import (
 	"sync"
 	"time"
 
-	maddr "go.unistack.org/micro/v4/util/addr"
-	mnet "go.unistack.org/micro/v4/util/net"
-	"go.unistack.org/micro/v4/util/rand"
+	maddr "go.unistack.org/micro/v3/util/addr"
+	mnet "go.unistack.org/micro/v3/util/net"
+	"go.unistack.org/micro/v3/util/rand"
 )
 
 type memorySocket struct {

network/transport/options.go

@@ -5,10 +5,10 @@ import (
 	"crypto/tls"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options struct holds the transport options

network/transport/transport.go

@@ -1,11 +1,11 @@
 // Package transport is an interface for synchronous connection based communication
-package transport // import "go.unistack.org/micro/v4/network/transport"
+package transport // import "go.unistack.org/micro/v3/network/transport"
 
 import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (

network/tunnel/broker/broker.go

@@ -1,15 +1,15 @@
 // Package broker is a tunnel broker
-package broker // import "go.unistack.org/micro/v4/network/tunnel/broker"
+package broker // import "go.unistack.org/micro/v3/network/tunnel/broker"
 
 import (
 	"context"
 	"fmt"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/network/tunnel"
 )
 
 type tunBroker struct {

network/tunnel/options.go

@@ -3,11 +3,11 @@ package tunnel
 import (
 	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 var (

network/tunnel/transport/listener.go

@@ -1,8 +1,8 @@
 package transport
 
 import (
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/network/tunnel"
 )
 
 type tunListener struct {

network/tunnel/transport/transport.go

@@ -1,12 +1,12 @@
 // Package transport provides a tunnel transport
-package transport // import "go.unistack.org/micro/v4/network/tunnel/transport"
+package transport // import "go.unistack.org/micro/v3/network/tunnel/transport"
 
 import (
 	"context"
 	"fmt"
 
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/network/tunnel"
 )
 
 type tunTransport struct {

network/tunnel/tunnel.go

@@ -1,12 +1,12 @@
 // Package tunnel provides gre network tunnelling
-package tunnel // import "go.unistack.org/micro/v4/network/transport/tunnel"
+package tunnel // import "go.unistack.org/micro/v3/network/transport/tunnel"
 
 import (
 	"context"
 	"errors"
 	"time"
 
-	"go.unistack.org/micro/v4/network/transport"
+	"go.unistack.org/micro/v3/network/transport"
 )
 
 // DefaultTunnel contains default tunnel implementation

options.go

@@ -5,17 +5,17 @@ import (
 	"fmt"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/config"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/server"
-	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/config"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options for micro service

options/hooks.go

@@ -1,4 +1,4 @@
-package options // import "go.unistack.org/micro/v4/options"
+package options // import "go.unistack.org/micro/v3/options"
 
 // Hook func interface
 type Hook interface{}

profiler/http/http.go

@@ -1,5 +1,5 @@
 // Package http enables the http profiler
-package http // import "go.unistack.org/micro/v4/profiler/http"
+package http // import "go.unistack.org/micro/v3/profiler/http"
 
 import (
 	"context"
@@ -7,7 +7,7 @@ import (
 	"net/http/pprof"
 	"sync"
 
-	profile "go.unistack.org/micro/v4/profiler"
+	profile "go.unistack.org/micro/v3/profiler"
 )
 
 type httpProfile struct {

profiler/pprof/pprof.go

@@ -1,5 +1,5 @@
 // Package pprof provides a pprof profiler which writes output to /tmp/[name].{cpu,mem}.pprof
-package pprof // import "go.unistack.org/micro/v4/profiler/pprof"
+package pprof // import "go.unistack.org/micro/v3/profiler/pprof"
 
 import (
 	"os"
@@ -9,7 +9,7 @@ import (
 	"sync"
 	"time"
 
-	profile "go.unistack.org/micro/v4/profiler"
+	profile "go.unistack.org/micro/v3/profiler"
 )
 
 type profiler struct {

profiler/profile.go

@@ -1,5 +1,5 @@
 // Package profiler is for profilers
-package profiler // import "go.unistack.org/micro/v4/profiler"
+package profiler // import "go.unistack.org/micro/v3/profiler"
 
 // Profiler interface
 type Profiler interface {

proxy/options.go

@@ -2,11 +2,11 @@
 package proxy
 
 import (
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options for proxy

proxy/proxy.go

@@ -1,10 +1,10 @@
 // Package proxy is a transparent proxy built on the micro/server
-package proxy // import "go.unistack.org/micro/v4/proxy"
+package proxy // import "go.unistack.org/micro/v3/proxy"
 
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v3/server"
 )
 
 // DefaultEndpoint holds default proxy address

register/extractor.go

@@ -6,7 +6,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 // ExtractValue from reflect.Type from specified depth

register/memory.go

@@ -5,8 +5,8 @@ import (
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 var (

register/options.go

@@ -5,9 +5,9 @@ import (
 	"crypto/tls"
 	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options holds options for register

register/register.go

@@ -1,11 +1,11 @@
 // Package register is an interface for service discovery
-package register // import "go.unistack.org/micro/v4/register"
+package register // import "go.unistack.org/micro/v3/register"
 
 import (
 	"context"
 	"errors"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 const (

resolver/dns/dns.go

@@ -1,5 +1,5 @@
 // Package dns resolves names to dns records
-package dns // import "go.unistack.org/micro/v4/resolver/dns"
+package dns // import "go.unistack.org/micro/v3/resolver/dns"
 
 import (
 	"context"
@@ -7,7 +7,7 @@ import (
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // Resolver is a DNS network resolve

resolver/dnssrv/dnssrv.go

@@ -1,11 +1,11 @@
 // Package dnssrv resolves names to dns srv records
-package dnssrv // import "go.unistack.org/micro/v4/resolver/dnssrv"
+package dnssrv // import "go.unistack.org/micro/v3/resolver/dnssrv"
 
 import (
 	"fmt"
 	"net"
 
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // Resolver is a DNS network resolve

resolver/http/http.go

@@ -1,5 +1,5 @@
 // Package http resolves names to network addresses using a http request
-package http // import "go.unistack.org/micro/v4/resolver/http"
+package http // import "go.unistack.org/micro/v3/resolver/http"
 
 import (
 	"encoding/json"
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"net/url"
 
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // nolint: golint,revive

resolver/noop/noop.go

@@ -1,8 +1,8 @@
 // Package noop is a noop resolver
-package noop // import "go.unistack.org/micro/v4/resolver/noop"
+package noop // import "go.unistack.org/micro/v3/resolver/noop"
 
 import (
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // Resolver contains noop resolver

resolver/registry/registry.go

@@ -1,11 +1,11 @@
 // Package register resolves names using the micro register
-package register // import "go.unistack.org/micro/v4/resolver/registry"
+package register // import "go.unistack.org/micro/v3/resolver/registry"
 
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // Resolver is a register network resolver

resolver/resolver.go

@@ -1,5 +1,5 @@
 // Package resolver resolves network names to addresses
-package resolver // import "go.unistack.org/micro/v4/resolver"
+package resolver // import "go.unistack.org/micro/v3/resolver"
 
 // Resolver is network resolver. It's used to find network nodes
 // via the name to connect to. This is done based on Network.Name().

resolver/static/static.go

@@ -1,8 +1,8 @@
 // Package static is a static resolver
-package static // import "go.unistack.org/micro/v4/resolver/static"
+package static // import "go.unistack.org/micro/v3/resolver/static"
 
 import (
-	"go.unistack.org/micro/v4/resolver"
+	"go.unistack.org/micro/v3/resolver"
 )
 
 // Resolver returns a static list of nodes. In the event the node list

router/options.go

@@ -3,9 +3,9 @@ package router
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 // Options are router options

router/route.go

@@ -3,7 +3,7 @@ package router
 import (
 	"hash/fnv"
 
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (

router/router.go

@@ -1,5 +1,5 @@
 // Package router provides a network routing control plane
-package router // import "go.unistack.org/micro/v4/router"
+package router // import "go.unistack.org/micro/v3/router"
 
 import (
 	"errors"

selector/random/random.go

@@ -1,8 +1,8 @@
-package random // import "go.unistack.org/micro/v4/selector/random"
+package random // import "go.unistack.org/micro/v3/selector/random"
 
 import (
-	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v4/util/rand"
+	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v3/util/rand"
 )
 
 type random struct{}

selector/random/random_test.go

@@ -3,7 +3,7 @@ package random
 import (
 	"testing"
 
-	"go.unistack.org/micro/v4/selector"
+	"go.unistack.org/micro/v3/selector"
 )
 
 func TestRandom(t *testing.T) {

selector/roundrobin/roundrobin.go

@@ -1,8 +1,8 @@
-package roundrobin // import "go.unistack.org/micro/v4/selector/roundrobin"
+package roundrobin // import "go.unistack.org/micro/v3/selector/roundrobin"
 
 import (
-	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v4/util/rand"
+	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v3/util/rand"
 )
 
 // NewSelector returns an initialised round robin selector

selector/roundrobin/roundrobin_test.go

@@ -3,7 +3,7 @@ package roundrobin
 import (
 	"testing"
 
-	"go.unistack.org/micro/v4/selector"
+	"go.unistack.org/micro/v3/selector"
 )
 
 func TestRoundRobin(t *testing.T) {

selector/selector.go

@@ -1,5 +1,5 @@
 // Package selector is for node selection and load balancing
-package selector // import "go.unistack.org/micro/v4/selector"
+package selector // import "go.unistack.org/micro/v3/selector"
 
 import (
 	"errors"

server/errors.go

@@ -1,6 +1,6 @@
 package server
 
-import "go.unistack.org/micro/v4/errors"
+import "go.unistack.org/micro/v3/errors"
 
 type Error struct {
 	id string

server/errors_test.go

@@ -3,7 +3,7 @@ package server
 import (
 	"testing"
 
-	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v3/errors"
 )
 
 func TestError(t *testing.T) {

server/handler.go

@@ -3,7 +3,7 @@ package server
 import (
 	"reflect"
 
-	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v3/register"
 )
 
 type rpcHandler struct {

server/noop.go

@@ -6,13 +6,13 @@ import (
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/register"
-	maddr "go.unistack.org/micro/v4/util/addr"
-	mnet "go.unistack.org/micro/v4/util/net"
-	"go.unistack.org/micro/v4/util/rand"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/register"
+	maddr "go.unistack.org/micro/v3/util/addr"
+	mnet "go.unistack.org/micro/v3/util/net"
+	"go.unistack.org/micro/v3/util/rand"
 )
 
 // DefaultCodecs will be used to encode/decode
@@ -202,39 +202,6 @@ func (n *noopServer) Register() error {
 	n.Lock()
 	defer n.Unlock()
 
-	cx := config.Context
-
-	var sub broker.Subscriber
-
-	for sb := range n.subscribers {
-		if sb.Options().Context != nil {
-			cx = sb.Options().Context
-		}
-
-		opts := []broker.SubscribeOption{broker.SubscribeContext(cx), broker.SubscribeAutoAck(sb.Options().AutoAck)}
-		if queue := sb.Options().Queue; len(queue) > 0 {
-			opts = append(opts, broker.SubscribeGroup(queue))
-		}
-
-		if sb.Options().Batch {
-			// batch processing handler
-			sub, err = config.Broker.BatchSubscribe(cx, sb.Topic(), n.newBatchSubHandler(sb, config), opts...)
-		} else {
-			// single processing handler
-			sub, err = config.Broker.Subscribe(cx, sb.Topic(), n.newSubHandler(sb, config), opts...)
-		}
-
-		if err != nil {
-			return err
-		}
-
-		if config.Logger.V(logger.InfoLevel) {
-			config.Logger.Infof(n.opts.Context, "subscribing to topic: %s", sb.Topic())
-		}
-
-		n.subscribers[sb] = []broker.Subscriber{sub}
-	}
-
 	n.registered = true
 	if cacheService {
 		n.rsvc = service
@@ -366,6 +333,10 @@ func (n *noopServer) Start() error {
 		}
 	}
 
+	if err := n.subscribe(); err != nil {
+		return err
+	}
+
 	go func() {
 		t := new(time.Ticker)
 
@@ -449,6 +420,45 @@ func (n *noopServer) Start() error {
 	return nil
 }
 
+func (n *noopServer) subscribe() error {
+	config := n.Options()
+
+	cx := config.Context
+	var err error
+	var sub broker.Subscriber
+
+	for sb := range n.subscribers {
+		if sb.Options().Context != nil {
+			cx = sb.Options().Context
+		}
+
+		opts := []broker.SubscribeOption{broker.SubscribeContext(cx), broker.SubscribeAutoAck(sb.Options().AutoAck)}
+		if queue := sb.Options().Queue; len(queue) > 0 {
+			opts = append(opts, broker.SubscribeGroup(queue))
+		}
+
+		if sb.Options().Batch {
+			// batch processing handler
+			sub, err = config.Broker.BatchSubscribe(cx, sb.Topic(), n.createBatchSubHandler(sb, config), opts...)
+		} else {
+			// single processing handler
+			sub, err = config.Broker.Subscribe(cx, sb.Topic(), n.createSubHandler(sb, config), opts...)
+		}
+
+		if err != nil {
+			return err
+		}
+
+		if config.Logger.V(logger.InfoLevel) {
+			config.Logger.Infof(n.opts.Context, "subscribing to topic: %s", sb.Topic())
+		}
+
+		n.subscribers[sb] = []broker.Subscriber{sub}
+	}
+
+	return nil
+}
+
 func (n *noopServer) Stop() error {
 	n.RLock()
 	if !n.started {

server/noop_test.go

@@ -5,12 +5,12 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/server"
 )
 
 type TestHandler struct {

server/options.go

@@ -7,16 +7,16 @@ import (
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v4/util/id"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 // Option func

server/registry.go

@@ -4,10 +4,10 @@ import (
 	"net"
 	"time"
 
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/util/addr"
-	"go.unistack.org/micro/v4/util/backoff"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/util/addr"
+	"go.unistack.org/micro/v3/util/backoff"
 )
 
 var (

server/request.go

@@ -1,8 +1,8 @@
 package server
 
 import (
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 type rpcMessage struct {

server/server.go

@@ -1,13 +1,13 @@
 // Package server is an interface for a micro server
-package server // import "go.unistack.org/micro/v4/server"
+package server // import "go.unistack.org/micro/v3/server"
 
 import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/register"
 )
 
 // DefaultServer default server
@@ -145,11 +145,12 @@ type Stream interface {
 //
 // Example:
 //
-//	type Greeter struct {}
+//      type Greeter struct {}
+//
+//      func (g *Greeter) Hello(context, request, response) error {
+//              return nil
+//      }
 //
-//	func (g *Greeter) Hello(context, request, response) error {
-//	        return nil
-//	}
 type Handler interface {
 	Name() string
 	Handler() interface{}

server/subscriber.go

@@ -10,12 +10,12 @@ import (
 	"unicode"
 	"unicode/utf8"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/errors"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/register"
 )
 
 const (
@@ -191,7 +191,7 @@ func newSubscriber(topic string, sub interface{}, opts ...SubscriberOption) Subs
 }
 
 //nolint:gocyclo
-func (n *noopServer) newBatchSubHandler(sb *subscriber, opts Options) broker.BatchHandler {
+func (n *noopServer) createBatchSubHandler(sb *subscriber, opts Options) broker.BatchHandler {
 	return func(ps broker.Events) (err error) {
 		defer func() {
 			if r := recover(); r != nil {
@@ -309,7 +309,7 @@ func (n *noopServer) newBatchSubHandler(sb *subscriber, opts Options) broker.Bat
 }
 
 //nolint:gocyclo
-func (n *noopServer) newSubHandler(sb *subscriber, opts Options) broker.Handler {
+func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handler {
 	return func(p broker.Event) (err error) {
 		defer func() {
 			if r := recover(); r != nil {

service.go

@@ -1,20 +1,20 @@
 // Package micro is a pluggable framework for microservices
-package micro // import "go.unistack.org/micro/v4"
+package micro // import "go.unistack.org/micro/v3"
 
 import (
 	"fmt"
 	"sync"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/config"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/server"
-	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/config"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Service is an interface that wraps the lower level components.
@@ -88,7 +88,6 @@ func (s *service) Name() string {
 // Init initialises options. Additionally it calls cmd.Init
 // which parses command line flags. cmd.Init is only called
 // on first Init.
-//
 //nolint:gocyclo
 func (s *service) Init(opts ...Option) error {
 	var err error

service_test.go

@@ -5,16 +5,16 @@ import (
 	"reflect"
 	"testing"
 
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/config"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/server"
-	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/config"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 type testItem struct {

store/memory_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 	"time"
 
-	"go.unistack.org/micro/v4/store"
+	"go.unistack.org/micro/v3/store"
 )
 
 func TestMemoryReInit(t *testing.T) {

store/options.go

@@ -5,11 +5,11 @@ import (
 	"crypto/tls"
 	"time"
 
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options contains configuration for the Store

store/store.go

@@ -1,5 +1,5 @@
 // Package store is an interface for distributed data storage.
-package store // import "go.unistack.org/micro/v4/store"
+package store // import "go.unistack.org/micro/v3/store"
 
 import (
 	"context"

sync/options.go

@@ -3,9 +3,9 @@ package sync
 import (
 	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options holds the sync options

sync/sync.go

@@ -1,5 +1,5 @@
 // Package sync is an interface for distributed synchronization
-package sync // import "go.unistack.org/micro/v4/sync"
+package sync // import "go.unistack.org/micro/v3/sync"
 
 import (
 	"errors"

tracer/noop.go

@@ -4,23 +4,37 @@ import (
 	"context"
 )
 
+var _ Tracer = (*noopTracer)(nil)
+
 type noopTracer struct {
-	opts Options
+	opts  Options
+	spans []Span
+}
+
+func (t *noopTracer) Spans() []Span {
+	return t.spans
 }
 
 func (t *noopTracer) Start(ctx context.Context, name string, opts ...SpanOption) (context.Context, Span) {
+	options := NewSpanOptions(opts...)
 	span := &noopSpan{
 		name:   name,
 		ctx:    ctx,
 		tracer: t,
-		opts:   NewSpanOptions(opts...),
+		labels: options.Labels,
+		kind:   options.Kind,
 	}
 	if span.ctx == nil {
 		span.ctx = context.Background()
 	}
+	t.spans = append(t.spans, span)
 	return NewSpanContext(ctx, span), span
 }
 
+func (t *noopTracer) Flush(ctx context.Context) error {
+	return nil
+}
+
 func (t *noopTracer) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&t.opts)
@@ -32,13 +46,21 @@ func (t *noopTracer) Name() string {
 	return t.opts.Name
 }
 
+type noopEvent struct {
+	name   string
+	labels []interface{}
+}
+
 type noopSpan struct {
 	ctx       context.Context
 	tracer    Tracer
 	name      string
-	opts      SpanOptions
-	status    SpanStatus
 	statusMsg string
+	events    []*noopEvent
+	labels    []interface{}
+	logs      []interface{}
+	kind      SpanKind
+	status    SpanStatus
 }
 
 func (s *noopSpan) Finish(opts ...SpanOption) {
@@ -53,22 +75,24 @@ func (s *noopSpan) Tracer() Tracer {
 }
 
 func (s *noopSpan) AddEvent(name string, opts ...EventOption) {
+	options := NewEventOptions(opts...)
+	s.events = append(s.events, &noopEvent{name: name, labels: options.Labels})
 }
 
 func (s *noopSpan) SetName(name string) {
 	s.name = name
 }
 
-func (s *noopSpan) SetLabels(labels ...interface{}) {
-	s.opts.Labels = labels
+func (s *noopSpan) AddLogs(kv ...interface{}) {
+	s.logs = append(s.logs, kv...)
 }
 
-func (s *noopSpan) AddLabels(labels ...interface{}) {
-	s.opts.Labels = append(s.opts.Labels, labels...)
+func (s *noopSpan) AddLabels(kv ...interface{}) {
+	s.labels = append(s.labels, kv...)
 }
 
 func (s *noopSpan) Kind() SpanKind {
-	return s.opts.Kind
+	return s.kind
 }
 
 func (s *noopSpan) Status() (SpanStatus, string) {

tracer/options.go

@@ -3,7 +3,7 @@ package tracer
 import (
 	"context"
 
-	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v3/logger"
 )
 
 type SpanStatus int
@@ -91,14 +91,22 @@ type SpanOptions struct {
 type SpanOption func(o *SpanOptions)
 
 // EventOptions contains event options
-type EventOptions struct{}
+type EventOptions struct {
+	Labels []interface{}
+}
 
 // EventOption func signature
 type EventOption func(o *EventOptions)
 
-func WithSpanLabels(labels ...interface{}) SpanOption {
+func WithEventLabels(kv ...interface{}) EventOption {
+	return func(o *EventOptions) {
+		o.Labels = kv
+	}
+}
+
+func WithSpanLabels(kv ...interface{}) SpanOption {
 	return func(o *SpanOptions) {
-		o.Labels = labels
+		o.Labels = kv
 	}
 }
 
@@ -128,6 +136,15 @@ func Logger(l logger.Logger) Option {
 	}
 }
 
+// NewEventOptions returns default EventOptions
+func NewEventOptions(opts ...EventOption) EventOptions {
+	options := EventOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
 // NewSpanOptions returns default SpanOptions
 func NewSpanOptions(opts ...SpanOption) SpanOptions {
 	options := SpanOptions{

tracer/tracer.go

@@ -1,8 +1,10 @@
 // Package tracer provides an interface for distributed tracing
-package tracer // import "go.unistack.org/micro/v4/tracer"
+package tracer // import "go.unistack.org/micro/v3/tracer"
 
 import (
 	"context"
+	"fmt"
+	"sort"
 )
 
 // DefaultTracer is the global default tracer
@@ -16,6 +18,8 @@ type Tracer interface {
 	Init(...Option) error
 	// Start a trace
 	Start(ctx context.Context, name string, opts ...SpanOption) (context.Context, Span)
+	// Flush flushes spans
+	Flush(ctx context.Context) error
 }
 
 type Span interface {
@@ -23,8 +27,6 @@ type Span interface {
 	Tracer() Tracer
 	// Finish complete and send span
 	Finish(opts ...SpanOption)
-	// AddEvent add event to span
-	AddEvent(name string, opts ...EventOption)
 	// Context return context with span
 	Context() context.Context
 	// SetName set the span name
@@ -33,10 +35,46 @@ type Span interface {
 	SetStatus(status SpanStatus, msg string)
 	// Status returns span status and msg
 	Status() (SpanStatus, string)
-	// SetLabels set the span labels
-	SetLabels(labels ...interface{})
-	// AddLabels append the span labels
-	AddLabels(labels ...interface{})
+	// AddLabels append labels to span
+	AddLabels(kv ...interface{})
+	// AddEvent append event to span
+	AddEvent(name string, opts ...EventOption)
+	// AddEvent append event to span
+	AddLogs(kv ...interface{})
 	// Kind returns span kind
 	Kind() SpanKind
 }
+
+// sort labels alphabeticaly by label name
+type byKey []interface{}
+
+func (k byKey) Len() int           { return len(k) / 2 }
+func (k byKey) Less(i, j int) bool { return fmt.Sprintf("%s", k[i*2]) < fmt.Sprintf("%s", k[j*2]) }
+func (k byKey) Swap(i, j int) {
+	k[i*2], k[j*2] = k[j*2], k[i*2]
+	k[i*2+1], k[j*2+1] = k[j*2+1], k[i*2+1]
+}
+
+func UniqLabels(labels []interface{}) []interface{} {
+	if len(labels)%2 == 1 {
+		labels = labels[:len(labels)-1]
+	}
+
+	if len(labels) > 2 {
+		sort.Sort(byKey(labels))
+
+		idx := 0
+		for {
+			if labels[idx] == labels[idx+2] {
+				copy(labels[idx:], labels[idx+2:])
+				labels = labels[:len(labels)-2]
+			} else {
+				idx += 2
+			}
+			if idx+2 >= len(labels) {
+				break
+			}
+		}
+	}
+	return labels
+}

tracer/tracer_test.go

@@ -0,0 +1,13 @@
+package tracer
+
+import (
+	"testing"
+)
+
+func TestUniqLabels(t *testing.T) {
+	labels := []interface{}{"key1", "val1", "key1", "val2"}
+	labels = UniqLabels(labels)
+	if labels[1] != "val2" {
+		t.Fatalf("UniqLabels not works")
+	}
+}