Merge pull request 'logger/slog: fixup old format' (#291) from fixupslog into v3

Reviewed-on: #291

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

@@ -1,24 +1,22 @@
 // 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
-var DefaultBroker Broker // =  NewBroker()
+var DefaultBroker = NewBroker()
 
 var (
 	// ErrNotConnected returns when broker used but not connected yet
 	ErrNotConnected = errors.New("broker not connected")
 	// ErrDisconnected returns when broker disconnected
 	ErrDisconnected = errors.New("broker disconnected")
-	// ErrInvalidMessage returns when message has nvalid format
-	ErrInvalidMessage = errors.New("broker message has invalid format")
 )
 
 // Broker is an interface used for asynchronous messaging.
@@ -35,33 +33,61 @@ type Broker interface {
 	Connect(ctx context.Context) error
 	// Disconnect disconnect from broker
 	Disconnect(ctx context.Context) error
-	// NewMessage creates new broker message
-	NewMessage(endpoint string, req interface{}, opts ...MessageOption) Message
 	// Publish message to broker topic
-	Publish(ctx context.Context, msg interface{}, opts ...PublishOption) error
+	Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
 	// Subscribe subscribes to topic message via handler
-	Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error)
+	Subscribe(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
+	// BatchPublish messages to broker with multiple topics
+	BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error
+	// BatchSubscribe subscribes to topic messages via handler
+	BatchSubscribe(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
 	// String type of broker
 	String() string
 }
 
-// Message is given to a subscription handler for processing
-type Message interface {
-	// Context for the message
-	Context() context.Context
+// Handler is used to process messages via a subscription of a topic.
+type Handler func(Event) error
+
+// Events contains multiple events
+type Events []Event
+
+// Ack try to ack all events and return
+func (evs Events) Ack() error {
+	var err error
+	for _, ev := range evs {
+		if err = ev.Ack(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// SetError sets error on event
+func (evs Events) SetError(err error) {
+	for _, ev := range evs {
+		ev.SetError(err)
+	}
+}
+
+// BatchHandler is used to process messages in batches via a subscription of a topic.
+type BatchHandler func(Events) error
+
+// Event is given to a subscription handler for processing
+type Event interface {
 	// Topic returns event topic
 	Topic() string
-	// Body returns broker message
-	Body() interface{}
+	// Message returns broker message
+	Message() *Message
 	// Ack acknowledge message
 	Ack() error
 	// Error returns message error (like decoding errors or some other)
-	// In this case Body contains raw []byte from broker
 	Error() error
+	// SetError set event processing error
+	SetError(err error)
 }
 
-// RawMessage is used to transfer data
-type RawMessage struct {
+// Message is used to transfer data
+type Message struct {
 	// Header contains message metadata
 	Header metadata.Metadata
 	// Body contains message body
@@ -69,8 +95,8 @@ type RawMessage struct {
 }
 
 // NewMessage create broker message with topic filled
-func NewRawMessage(topic string) *RawMessage {
-	m := &RawMessage{Header: metadata.New(2)}
+func NewMessage(topic string) *Message {
+	m := &Message{Header: metadata.New(2)}
 	m.Header.Set(metadata.HeaderTopic, topic)
 	return m
 }

broker/memory.go

@@ -1,17 +1,15 @@
-//go:build ignore
-
 package broker
 
 import (
 	"context"
 	"sync"
-	"time"
 
-	"go.unistack.org/micro/v4/logger"
-	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 {
@@ -22,6 +20,23 @@ type memoryBroker struct {
 	connected bool
 }
 
+type memoryEvent struct {
+	err     error
+	message interface{}
+	topic   string
+	opts    Options
+}
+
+type memorySubscriber struct {
+	ctx          context.Context
+	exit         chan bool
+	handler      Handler
+	batchhandler BatchHandler
+	id           string
+	topic        string
+	opts         SubscribeOptions
+}
+
 func (m *memoryBroker) Options() Options {
 	return m.opts
 }
@@ -73,11 +88,16 @@ func (m *memoryBroker) Init(opts ...Option) error {
 	return nil
 }
 
-func (m *memoryBroker) NewMessage(endpoint string, req interface{}, opts ...MessageOption) Message {
-	return &memoryMessage{}
+func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+	msg.Header.Set(metadata.HeaderTopic, topic)
+	return m.publish(ctx, []*Message{msg}, opts...)
 }
 
-func (m *memoryBroker) Publish(ctx context.Context, message interface{}, opts ...PublishOption) error {
+func (m *memoryBroker) BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
+	return m.publish(ctx, msgs, opts...)
+}
+
+func (m *memoryBroker) publish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
 	m.RLock()
 	if !m.connected {
 		m.RUnlock()
@@ -92,94 +112,128 @@ func (m *memoryBroker) Publish(ctx context.Context, message interface{}, opts ..
 		return ctx.Err()
 	default:
 		options := NewPublishOptions(opts...)
-		var msgs []*memoryMessage
-		switch v := message.(type) {
-		case *memoryMessage:
-			msgs = []*memoryMessage{v}
-		case []*memoryMessage:
-			msgs = v
-		default:
-			return ErrInvalidMessage
-		}
-		msgTopicMap := make(map[string][]*memoryMessage)
-		for _, msg := range msgs {
-			p := &memoryMessage{opts: options}
-			/*
-				if mb, ok := msg.Body().(*codec.Frame); ok {
-					p.message = v.Body
-				} else {
-					p.topic, _ = v.Header.Get(metadata.HeaderTopic)
-					p.message, err = m.opts.Codec.Marshal(v)
-					if err != nil {
-						return err
-					}
+
+		msgTopicMap := make(map[string]Events)
+		for _, v := range msgs {
+			p := &memoryEvent{opts: m.opts}
+
+			if m.opts.Codec == nil || options.BodyOnly {
+				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+				p.message = v.Body
+			} else {
+				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+				p.message, err = m.opts.Codec.Marshal(v)
+				if err != nil {
+					return err
 				}
-			*/
-			msgTopicMap[msg.Topic()] = append(msgTopicMap[p.topic], p)
+			}
+			msgTopicMap[p.topic] = append(msgTopicMap[p.topic], p)
 		}
 
+		beh := m.opts.BatchErrorHandler
 		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
+				}
 				if sub.opts.ErrorHandler != nil {
 					eh = sub.opts.ErrorHandler
 				}
 
-				for _, p := range ms {
-					if err = sub.handler(p); err != nil {
-						m.opts.Meter.Counter(SubscribeMessageTotal, "endpoint", t, "status", "failure").Inc()
-						if eh != nil {
-							_ = eh(p)
+				switch {
+				// batch processing
+				case sub.batchhandler != nil:
+					if err = sub.batchhandler(ms); err != nil {
+						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 = 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 = ms.Ack(); err != nil {
+							m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
+						}
+					}
+					// single processing
+				case sub.handler != nil:
+					for _, p := range ms {
+						if err = sub.handler(p); err != nil {
+							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(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
 }
 
-func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error) {
+func (m *memoryBroker) BatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
+	m.RLock()
+	if !m.connected {
+		m.RUnlock()
+		return nil, ErrNotConnected
+	}
+	m.RUnlock()
+
+	sid, err := id.New()
+	if err != nil {
+		return nil, err
+	}
+
+	options := NewSubscribeOptions(opts...)
+
+	sub := &memorySubscriber{
+		exit:         make(chan bool, 1),
+		id:           sid,
+		topic:        topic,
+		batchhandler: handler,
+		opts:         options,
+		ctx:          ctx,
+	}
+
+	m.Lock()
+	m.subscribers[topic] = append(m.subscribers[topic], sub)
+	m.Unlock()
+
+	go func() {
+		<-sub.exit
+		m.Lock()
+		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
+		for _, sb := range m.subscribers[topic] {
+			if sb.id == sub.id {
+				continue
+			}
+			newSubscribers = append(newSubscribers, sb)
+		}
+		m.subscribers[topic] = newSubscribers
+		m.Unlock()
+	}()
+
+	return sub, nil
+}
+
+func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
 	m.RLock()
 	if !m.connected {
 		m.RUnlock()
@@ -232,41 +286,38 @@ func (m *memoryBroker) Name() string {
 	return m.opts.Name
 }
 
-type memoryMessage struct {
-	err   error
-	body  interface{}
-	topic string
-	opts  PublishOptions
-	ctx   context.Context
-}
-
-func (m *memoryMessage) Topic() string {
+func (m *memoryEvent) Topic() string {
 	return m.topic
 }
 
-func (m *memoryMessage) Body() interface{} {
-	return m.body
-}
+func (m *memoryEvent) Message() *Message {
+	switch v := m.message.(type) {
+	case *Message:
+		return v
+	case []byte:
+		msg := &Message{}
+		if err := m.opts.Codec.Unmarshal(v, msg); err != nil {
+			if m.opts.Logger.V(logger.ErrorLevel) {
+				m.opts.Logger.Error(m.opts.Context, "[memory]: failed to unmarshal: %v", err)
+			}
+			return nil
+		}
+		return msg
+	}
 
-func (m *memoryMessage) Ack() error {
 	return nil
 }
 
-func (m *memoryMessage) Error() error {
+func (m *memoryEvent) Ack() error {
+	return nil
+}
+
+func (m *memoryEvent) Error() error {
 	return m.err
 }
 
-func (m *memoryMessage) Context() context.Context {
-	return m.ctx
-}
-
-type memorySubscriber struct {
-	ctx     context.Context
-	exit    chan bool
-	handler interface{}
-	id      string
-	topic   string
-	opts    SubscribeOptions
+func (m *memoryEvent) SetError(err error) {
+	m.err = err
 }
 
 func (m *memorySubscriber) Options() SubscribeOptions {
@@ -283,7 +334,7 @@ func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
 }
 
 // NewBroker return new memory broker
-func NewBroker(opts ...Option) *memoryBroker {
+func NewBroker(opts ...Option) Broker {
 	return &memoryBroker{
 		opts:        NewOptions(opts...),
 		subscribers: make(map[string][]*memorySubscriber),

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

@@ -5,31 +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/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
@@ -38,8 +18,8 @@ type Options struct {
 	Tracer tracer.Tracer
 	// Register can be used for clustering
 	Register register.Register
-	// Codecs holds the codec for marshal/unmarshal
-	Codecs map[string]codec.Codec
+	// Codec holds the codec for marshal/unmarshal
+	Codec codec.Codec
 	// Logger used for logging
 	Logger logger.Logger
 	// Meter used for metrics
@@ -49,16 +29,15 @@ type Options struct {
 	// TLSConfig holds tls.TLSConfig options
 	TLSConfig *tls.Config
 	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler func(Message)
+	ErrorHandler Handler
+	// BatchErrorHandler used when broker can't unmashal incoming messages
+	BatchErrorHandler BatchHandler
 	// Name holds the broker name
 	Name string
 	// Addrs holds the broker address
 	Addrs []string
 }
 
-// Option func
-type Option func(*Options)
-
 // NewOptions create new Options
 func NewOptions(opts ...Option) Options {
 	options := Options{
@@ -66,7 +45,7 @@ func NewOptions(opts ...Option) Options {
 		Logger:   logger.DefaultLogger,
 		Context:  context.Background(),
 		Meter:    meter.DefaultMeter,
-		Codecs:   make(map[string]codec.Codec),
+		Codec:    codec.DefaultCodec,
 		Tracer:   tracer.DefaultTracer,
 	}
 	for _, o := range opts {
@@ -82,32 +61,6 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// MessageOption func
-type MessageOption func(*MessageOptions)
-
-// MessageOptions struct
-type MessageOptions struct {
-	Metadata    metadata.Metadata
-	ContentType string
-}
-
-// MessageMetadata pass additional message metadata
-func MessageMetadata(md metadata.Metadata) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata = md
-	}
-}
-
-// MessageContentType pass ContentType for message data
-func MessageContentType(ct string) MessageOption {
-	return func(o *MessageOptions) {
-		o.ContentType = ct
-	}
-}
-
-// PublishOption func
-type PublishOption func(*PublishOptions)
-
 // PublishOptions struct
 type PublishOptions struct {
 	// Context holds external options
@@ -132,9 +85,11 @@ type SubscribeOptions struct {
 	// Context holds external options
 	Context context.Context
 	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler func(Message)
-	// QueueGroup holds consumer group
-	QueueGroup string
+	ErrorHandler Handler
+	// BatchErrorHandler used when broker can't unmashal incoming messages
+	BatchErrorHandler BatchHandler
+	// Group holds consumer group
+	Group string
 	// AutoAck flag specifies auto ack of incoming message when no error happens
 	AutoAck bool
 	// BodyOnly flag specifies that message contains only body bytes without header
@@ -145,6 +100,12 @@ type SubscribeOptions struct {
 	BatchWait time.Duration
 }
 
+// Option func
+type Option func(*Options)
+
+// PublishOption func
+type PublishOption func(*PublishOptions)
+
 // PublishBodyOnly publish only body of the message
 func PublishBodyOnly(b bool) PublishOption {
 	return func(o *PublishOptions) {
@@ -168,29 +129,59 @@ func Addrs(addrs ...string) Option {
 
 // Codec sets the codec used for encoding/decoding used where
 // a broker does not support headers
-// Codec to be used to encode/decode requests for a given content type
-func Codec(contentType string, c codec.Codec) Option {
+func Codec(c codec.Codec) Option {
 	return func(o *Options) {
-		o.Codecs[contentType] = c
+		o.Codec = c
 	}
 }
 
 // ErrorHandler will catch all broker errors that cant be handled
 // in normal way, for example Codec errors
-func ErrorHandler(h func(Message)) Option {
+func ErrorHandler(h Handler) Option {
 	return func(o *Options) {
 		o.ErrorHandler = h
 	}
 }
 
+// BatchErrorHandler will catch all broker errors that cant be handled
+// in normal way, for example Codec errors
+func BatchErrorHandler(h BatchHandler) Option {
+	return func(o *Options) {
+		o.BatchErrorHandler = h
+	}
+}
+
 // SubscribeErrorHandler will catch all broker errors that cant be handled
 // in normal way, for example Codec errors
-func SubscribeErrorHandler(h func(Message)) SubscribeOption {
+func SubscribeErrorHandler(h Handler) SubscribeOption {
 	return func(o *SubscribeOptions) {
 		o.ErrorHandler = h
 	}
 }
 
+// SubscribeBatchErrorHandler will catch all broker errors that cant be handled
+// in normal way, for example Codec errors
+func SubscribeBatchErrorHandler(h BatchHandler) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchErrorHandler = h
+	}
+}
+
+// Queue sets the subscribers queue
+// Deprecated
+func Queue(name string) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.Group = name
+	}
+}
+
+// SubscribeGroup sets the name of the queue to share messages on
+func SubscribeGroup(name string) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.Group = name
+	}
+}
+
 // Register sets register option
 func Register(r register.Register) Option {
 	return func(o *Options) {
@@ -233,21 +224,6 @@ func Name(n string) Option {
 	}
 }
 
-// SubscribeOption func signature
-type SubscribeOption func(*SubscribeOptions)
-
-// NewSubscribeOptions creates new SubscribeOptions
-func NewSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
-	options := SubscribeOptions{
-		AutoAck: true,
-		Context: context.Background(),
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
 // SubscribeContext set context
 func SubscribeContext(ctx context.Context) SubscribeOption {
 	return func(o *SubscribeOptions) {
@@ -255,6 +231,14 @@ func SubscribeContext(ctx context.Context) SubscribeOption {
 	}
 }
 
+// DisableAutoAck disables auto ack
+// Deprecated
+func DisableAutoAck() SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.AutoAck = false
+	}
+}
+
 // SubscribeAutoAck contol auto acking of messages
 // after they have been handled.
 func SubscribeAutoAck(b bool) SubscribeOption {
@@ -284,16 +268,17 @@ func SubscribeBatchWait(td time.Duration) SubscribeOption {
 	}
 }
 
-// SubscribeQueueGroup sets the shared queue name distributed messages across subscribers
-func SubscribeQueueGroup(n string) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.QueueGroup = n
-	}
-}
+// SubscribeOption func
+type SubscribeOption func(*SubscribeOptions)
 
-// SubscribeAutoAck control auto ack processing for handler
-func SubscribeAuthAck(b bool) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = b
+// NewSubscribeOptions creates new SubscribeOptions
+func NewSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
+	options := SubscribeOptions{
+		AutoAck: true,
+		Context: context.Background(),
 	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
 }

broker/subscriber.go

@@ -1,98 +0,0 @@
-package broker
-
-import (
-	"fmt"
-	"reflect"
-	"strings"
-	"unicode"
-	"unicode/utf8"
-)
-
-const (
-	subSig      = "func(context.Context, interface{}) error"
-	batchSubSig = "func([]context.Context, []interface{}) error"
-)
-
-// Precompute the reflect type for error. Can't use error directly
-// because Typeof takes an empty interface value. This is annoying.
-var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
-
-// Is this an exported - upper case - name?
-func isExported(name string) bool {
-	rune, _ := utf8.DecodeRuneInString(name)
-	return unicode.IsUpper(rune)
-}
-
-// Is this type exported or a builtin?
-func isExportedOrBuiltinType(t reflect.Type) bool {
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-	// PkgPath will be non-empty even for an exported type,
-	// so we need to check the type name as well.
-	return isExported(t.Name()) || t.PkgPath() == ""
-}
-
-// ValidateSubscriber func signature
-func ValidateSubscriber(sub interface{}) error {
-	typ := reflect.TypeOf(sub)
-	var argType reflect.Type
-	switch typ.Kind() {
-	case reflect.Func:
-		name := "Func"
-		switch typ.NumIn() {
-		case 1: // func(Message) error
-
-		case 2: // func(context.Context, Message) error or func(context.Context, []Message) error
-			argType = typ.In(2)
-			// if sub.Options().Batch {
-			if argType.Kind() != reflect.Slice {
-				return fmt.Errorf("subscriber %v dont have required signature %s", name, batchSubSig)
-			}
-			if strings.Compare(fmt.Sprintf("%v", argType), "[]interface{}") == 0 {
-				return fmt.Errorf("subscriber %v dont have required signaure %s", name, batchSubSig)
-			}
-		//	}
-		default:
-			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s or %s", name, typ.NumIn(), subSig, batchSubSig)
-		}
-		if !isExportedOrBuiltinType(argType) {
-			return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
-		}
-		if typ.NumOut() != 1 {
-			return fmt.Errorf("subscriber %v has wrong number of return values: %v require signature %s or %s",
-				name, typ.NumOut(), subSig, batchSubSig)
-		}
-		if returnType := typ.Out(0); returnType != typeOfError {
-			return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
-		}
-	default:
-		hdlr := reflect.ValueOf(sub)
-		name := reflect.Indirect(hdlr).Type().Name()
-
-		for m := 0; m < typ.NumMethod(); m++ {
-			method := typ.Method(m)
-			switch method.Type.NumIn() {
-			case 3:
-				argType = method.Type.In(2)
-			default:
-				return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s or %s",
-					name, method.Name, method.Type.NumIn(), subSig, batchSubSig)
-			}
-
-			if !isExportedOrBuiltinType(argType) {
-				return fmt.Errorf("%v argument type not exported: %v", name, argType)
-			}
-			if method.Type.NumOut() != 1 {
-				return fmt.Errorf(
-					"subscriber %v.%v has wrong number of return values: %v require signature %s or %s",
-					name, method.Name, method.Type.NumOut(), subSig, batchSubSig)
-			}
-			if returnType := method.Type.Out(0); returnType != typeOfError {
-				return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
-			}
-		}
-	}
-
-	return nil
-}

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

@@ -1,11 +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/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (
@@ -34,12 +35,23 @@ type Client interface {
 	Name() string
 	Init(opts ...Option) error
 	Options() Options
+	NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
 	NewRequest(service string, endpoint string, req interface{}, opts ...RequestOption) Request
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
+	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
+	BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
 	String() string
 }
 
+// Message is the interface for publishing asynchronously
+type Message interface {
+	Topic() string
+	Payload() interface{}
+	ContentType() string
+	Metadata() metadata.Metadata
+}
+
 // Request is the interface for a synchronous request used by Call or Stream
 type Request interface {
 	// The service to call
@@ -56,22 +68,16 @@ type Request interface {
 	Codec() codec.Codec
 	// indicates whether the request will be a streaming one rather than unary
 	Stream() bool
-	// Header data
-	// Header() metadata.Metadata
 }
 
 // Response is the response received from a service
 type Response interface {
 	// Read the response
 	Codec() codec.Codec
-	// The content type
-	// ContentType() string
 	// Header data
-	// Header() metadata.Metadata
+	Header() metadata.Metadata
 	// Read the undecoded response
 	Read() ([]byte, error)
-	// The unencoded request body
-	// Body() interface{}
 }
 
 // Stream is the interface for a bidirectional synchronous stream

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

@@ -3,12 +3,14 @@ package client
 import (
 	"context"
 	"fmt"
+	"os"
 	"time"
 
-	"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
@@ -284,9 +286,6 @@ func (n *noopClient) Call(ctx context.Context, req Request, rsp interface{}, opt
 	ch := make(chan error, callOpts.Retries)
 	var gerr error
 
-	ts := time.Now()
-	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
-	n.opts.Meter.Counter(ClientRequestInflight, "endpoint", endpoint).Inc()
 	for i := 0; i <= callOpts.Retries; i++ {
 		go func() {
 			ch <- call(i)
@@ -314,16 +313,6 @@ func (n *noopClient) Call(ctx context.Context, req Request, rsp interface{}, opt
 		}
 	}
 
-	if gerr != nil {
-		n.opts.Meter.Counter(ClientRequestTotal, "endpoint", endpoint, "status", "failure").Inc()
-	} else {
-		n.opts.Meter.Counter(ClientRequestTotal, "endpoint", endpoint, "status", "success").Inc()
-	}
-	n.opts.Meter.Counter(ClientRequestInflight, "endpoint", endpoint).Dec()
-	te := time.Since(ts)
-	n.opts.Meter.Summary(ClientRequestLatencyMicroseconds, "endpoint", endpoint).Update(te.Seconds())
-	n.opts.Meter.Histogram(ClientRequestDurationSeconds, "endpoint", endpoint).Update(te.Seconds())
-
 	return gerr
 }
 
@@ -335,6 +324,11 @@ func (n *noopClient) NewRequest(service, endpoint string, req interface{}, opts
 	return &noopRequest{service: service, endpoint: endpoint}
 }
 
+func (n *noopClient) NewMessage(topic string, msg interface{}, opts ...MessageOption) Message {
+	options := NewMessageOptions(append([]MessageOption{MessageContentType(n.opts.ContentType)}, opts...)...)
+	return &noopMessage{topic: topic, payload: msg, opts: options}
+}
+
 func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error) {
 	var err error
 
@@ -421,15 +415,7 @@ func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption
 
 		node := next()
 
-		// ts := time.Now()
-		endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
-		n.opts.Meter.Counter(ClientRequestInflight, "endpoint", endpoint).Inc()
 		stream, cerr := n.stream(ctx, node, req, callOpts)
-		if cerr != nil {
-			n.opts.Meter.Counter(ClientRequestTotal, "endpoint", endpoint, "status", "failure").Inc()
-		} else {
-			n.opts.Meter.Counter(ClientRequestTotal, "endpoint", endpoint, "status", "success").Inc()
-		}
 
 		// record the result of the call to inform future routing decisions
 		if verr := n.opts.Selector.Record(node, cerr); verr != nil {
@@ -483,6 +469,77 @@ func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption
 	return nil, grr
 }
 
-func (n *noopClient) stream(ctx context.Context, addr string, req Request, opts CallOptions) (*noopStream, error) {
+func (n *noopClient) stream(ctx context.Context, addr string, req Request, opts CallOptions) (Stream, error) {
 	return &noopStream{}, nil
 }
+
+func (n *noopClient) BatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
+	return n.publish(ctx, ps, opts...)
+}
+
+func (n *noopClient) Publish(ctx context.Context, p Message, opts ...PublishOption) error {
+	return n.publish(ctx, []Message{p}, opts...)
+}
+
+func (n *noopClient) publish(ctx context.Context, ps []Message, opts ...PublishOption) error {
+	options := NewPublishOptions(opts...)
+
+	msgs := make([]*broker.Message, 0, len(ps))
+
+	// get proxy
+	exchange := ""
+	if v, ok := os.LookupEnv("MICRO_PROXY"); ok {
+		exchange = v
+	}
+	// get the exchange
+	if len(options.Exchange) > 0 {
+		exchange = options.Exchange
+	}
+
+	omd, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		omd = metadata.New(0)
+	}
+
+	for _, p := range ps {
+		md := metadata.Copy(omd)
+		md[metadata.HeaderContentType] = p.ContentType()
+		topic := p.Topic()
+		if len(exchange) > 0 {
+			topic = exchange
+		}
+		md[metadata.HeaderTopic] = topic
+		iter := p.Metadata().Iterator()
+		var k, v string
+		for iter.Next(&k, &v) {
+			md.Set(k, v)
+		}
+
+		var body []byte
+
+		// passed in raw data
+		if d, ok := p.Payload().(*codec.Frame); ok {
+			body = d.Data
+		} else {
+			// use codec for payload
+			cf, err := n.newCodec(p.ContentType())
+			if err != nil {
+				return errors.InternalServerError("go.micro.client", err.Error())
+			}
+
+			// set the body
+			b, err := cf.Marshal(p.Payload())
+			if err != nil {
+				return errors.InternalServerError("go.micro.client", err.Error())
+			}
+			body = b
+		}
+
+		msgs = append(msgs, &broker.Message{Header: md, Body: body})
+	}
+
+	return n.opts.Broker.BatchPublish(ctx, msgs,
+		broker.PublishContext(options.Context),
+		broker.PublishBodyOnly(options.BodyOnly),
+	)
+}

client/options.go

@@ -6,27 +6,17 @@ import (
 	"net"
 	"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/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"
-)
-
-var (
-	// ClientRequestDurationSeconds specifies meter metric name
-	ClientRequestDurationSeconds = "client_request_duration_seconds"
-	// ClientRequestLatencyMicroseconds specifies meter metric name
-	ClientRequestLatencyMicroseconds = "client_request_latency_microseconds"
-	// ClientRequestTotal specifies meter metric name
-	ClientRequestTotal = "client_request_total"
-	// ClientRequestInflight specifies meter metric name
-	ClientRequestInflight = "client_request_inflight"
+	"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
@@ -39,6 +29,8 @@ type Options struct {
 	Logger logger.Logger
 	// Tracer used for tracing
 	Tracer tracer.Tracer
+	// Broker used to publish messages
+	Broker broker.Broker
 	// Meter used for metrics
 	Meter meter.Meter
 	// Context is used for external options
@@ -207,6 +199,7 @@ func NewOptions(opts ...Option) Options {
 		PoolTTL:   DefaultPoolTTL,
 		Selector:  random.NewSelector(),
 		Logger:    logger.DefaultLogger,
+		Broker:    broker.DefaultBroker,
 		Meter:     meter.DefaultMeter,
 		Tracer:    tracer.DefaultTracer,
 		Router:    router.DefaultRouter,
@@ -220,6 +213,13 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// Broker to be used for pub/sub
+func Broker(b broker.Broker) Option {
+	return func(o *Options) {
+		o.Broker = b
+	}
+}
+
 // Tracer to be used for tracing
 func Tracer(t tracer.Tracer) Option {
 	return func(o *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

@@ -9,9 +9,9 @@ import (
 
 	"github.com/google/uuid"
 	"github.com/imdario/mergo"
-	mid "go.unistack.org/micro/v4/util/id"
-	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 {
@@ -39,6 +39,10 @@ func (c *defaultConfig) Init(opts ...Option) error {
 }
 
 func (c *defaultConfig) Load(ctx context.Context, opts ...LoadOption) error {
+	if c.opts.SkipLoad != nil && c.opts.SkipLoad(ctx, c) {
+		return nil
+	}
+
 	if err := DefaultBeforeLoad(ctx, c); err != nil && !c.opts.AllowFail {
 		return err
 	}
@@ -185,7 +189,7 @@ 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
@@ -291,7 +295,11 @@ func fillValues(valueOf reflect.Value, tname string) error {
 	return nil
 }
 
-func (c *defaultConfig) Save(ctx context.Context, opts ...SaveOption) error {
+func (c *defaultConfig) Save(ctx context.Context, _ ...SaveOption) error {
+	if c.opts.SkipSave != nil && c.opts.SkipSave(ctx, c) {
+		return nil
+	}
+
 	if err := DefaultBeforeSave(ctx, c); err != nil {
 		return err
 	}

config/default_test.go

@@ -6,9 +6,9 @@ import (
 	"testing"
 	"time"
 
-	"go.unistack.org/micro/v4/config"
-	mid "go.unistack.org/micro/v4/util/id"
-	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 {

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
@@ -42,6 +42,10 @@ type Options struct {
 	AfterInit []func(context.Context, Config) error
 	// AllowFail flag to allow fail in config source
 	AllowFail bool
+	// SkipLoad runs only if condition returns true
+	SkipLoad func(context.Context, Config) bool
+	// SkipSave runs only if condition returns true
+	SkipSave func(context.Context, Config) bool
 }
 
 // Option function signature
@@ -68,9 +72,9 @@ type LoadOption func(o *LoadOptions)
 // LoadOptions struct
 type LoadOptions struct {
 	Struct   interface{}
+	Context  context.Context
 	Override bool
 	Append   bool
-	Context  context.Context
 }
 
 // NewLoadOptions create LoadOptions struct with provided opts

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

@@ -0,0 +1,27 @@
+package micro
+
+import (
+	"context"
+
+	"go.unistack.org/micro/v3/client"
+)
+
+// Event is used to publish messages to a topic
+type Event interface {
+	// Publish publishes a message to the event topic
+	Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error
+}
+
+type event struct {
+	c     client.Client
+	topic string
+}
+
+// NewEvent creates a new event publisher
+func NewEvent(topic string, c client.Client) Event {
+	return &event{c, topic}
+}
+
+func (e *event) Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error {
+	return e.c.Publish(ctx, e.c.NewMessage(e.topic, msg), opts...)
+}

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

@@ -1,6 +1,6 @@
-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
@@ -8,13 +8,13 @@ require (
 	github.com/imdario/mergo v0.3.15
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5
-	golang.org/x/sync v0.1.0
-	golang.org/x/sys v0.7.0
-	google.golang.org/grpc v1.54.0
-	google.golang.org/protobuf v1.30.0
+	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
-	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
+	golang.org/x/net v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230526203410-71b5a4ffd15e // indirect
 )

go.sum

@@ -13,21 +13,21 @@ github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaR
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 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 v0.8.0 h1:Zrh2ngAOFYneWTAIAPethzeaQLuHwhuBkuV6ZiRnUaQ=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
-golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/text v0.8.0 h1:57P1ETyNKtuIjB4SRd15iJxuhj8Gc416Y78H3qgMh68=
+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 v0.0.0-20230410155749-daa745c078e1 h1:KpwkzHKEF7B9Zxg18WzOa7djJ+Ha5DzthMyZYQfEn2A=
-google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1/go.mod h1:nKE/iIaLqn2bQwXBg8f1g2Ylh6r5MN5CmZvuzZCgsCU=
-google.golang.org/grpc v1.54.0 h1:EhTqbhiYeixwWQtAEZAxmV9MGqcjEU2mFx52xCzNyag=
-google.golang.org/grpc v1.54.0/go.mod h1:PUSEXI6iWghWaB6lXM4knEgpJNu2qUcKfDtNci3EC2g=
+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 v1.30.0 h1:kPPoIgf3TsEvrm0PFe15JQ+570QVxYzEvvHqChK+cng=
-google.golang.org/protobuf v1.30.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+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/default.go

@@ -1,230 +0,0 @@
-package logger
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"os"
-	"runtime"
-	"strings"
-	"sync"
-	"time"
-)
-
-type defaultLogger struct {
-	enc  *json.Encoder
-	opts Options
-	sync.RWMutex
-}
-
-// Init(opts...) should only overwrite provided options
-func (l *defaultLogger) Init(opts ...Option) error {
-	l.Lock()
-	for _, o := range opts {
-		o(&l.opts)
-	}
-	l.enc = json.NewEncoder(l.opts.Out)
-	// wrap the Log func
-	l.Unlock()
-	return nil
-}
-
-func (l *defaultLogger) String() string {
-	return "micro"
-}
-
-func (l *defaultLogger) Clone(opts ...Option) Logger {
-	newopts := NewOptions(opts...)
-	oldopts := l.opts
-	for _, o := range opts {
-		o(&newopts)
-		o(&oldopts)
-	}
-
-	l.Lock()
-	cl := &defaultLogger{opts: oldopts, enc: json.NewEncoder(l.opts.Out)}
-	l.Unlock()
-
-	return cl
-}
-
-func (l *defaultLogger) V(level Level) bool {
-	l.RLock()
-	ok := l.opts.Level.Enabled(level)
-	l.RUnlock()
-	return ok
-}
-
-func (l *defaultLogger) Level(level Level) {
-	l.Lock()
-	l.opts.Level = level
-	l.Unlock()
-}
-
-func (l *defaultLogger) Fields(fields ...interface{}) Logger {
-	l.RLock()
-	nl := &defaultLogger{opts: l.opts, enc: l.enc}
-	if len(fields) == 0 {
-		l.RUnlock()
-		return nl
-	} else if len(fields)%2 != 0 {
-		fields = fields[:len(fields)-1]
-	}
-	nl.opts.Fields = copyFields(l.opts.Fields)
-	nl.opts.Fields = append(nl.opts.Fields, fields...)
-	l.RUnlock()
-	return nl
-}
-
-func copyFields(src []interface{}) []interface{} {
-	dst := make([]interface{}, len(src))
-	copy(dst, src)
-	return dst
-}
-
-// logCallerfilePath returns a package/file:line description of the caller,
-// preserving only the leaf directory name and file name.
-func logCallerfilePath(loggingFilePath string) string {
-	// To make sure we trim the path correctly on Windows too, we
-	// counter-intuitively need to use '/' and *not* os.PathSeparator here,
-	// because the path given originates from Go stdlib, specifically
-	// runtime.Caller() which (as of Mar/17) returns forward slashes even on
-	// Windows.
-	//
-	// See https://github.com/golang/go/issues/3335
-	// and https://github.com/golang/go/issues/18151
-	//
-	// for discussion on the issue on Go side.
-	idx := strings.LastIndexByte(loggingFilePath, '/')
-	if idx == -1 {
-		return loggingFilePath
-	}
-	idx = strings.LastIndexByte(loggingFilePath[:idx], '/')
-	if idx == -1 {
-		return loggingFilePath
-	}
-	return loggingFilePath[idx+1:]
-}
-
-func (l *defaultLogger) Info(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, InfoLevel, args...)
-}
-
-func (l *defaultLogger) Error(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, ErrorLevel, args...)
-}
-
-func (l *defaultLogger) Debug(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, DebugLevel, args...)
-}
-
-func (l *defaultLogger) Warn(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, WarnLevel, args...)
-}
-
-func (l *defaultLogger) Trace(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, TraceLevel, args...)
-}
-
-func (l *defaultLogger) Fatal(ctx context.Context, args ...interface{}) {
-	l.Log(ctx, FatalLevel, args...)
-	os.Exit(1)
-}
-
-func (l *defaultLogger) Infof(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, InfoLevel, msg, args...)
-}
-
-func (l *defaultLogger) Errorf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, ErrorLevel, msg, args...)
-}
-
-func (l *defaultLogger) Debugf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, DebugLevel, msg, args...)
-}
-
-func (l *defaultLogger) Warnf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, WarnLevel, msg, args...)
-}
-
-func (l *defaultLogger) Tracef(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, TraceLevel, msg, args...)
-}
-
-func (l *defaultLogger) Fatalf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, FatalLevel, msg, args...)
-	os.Exit(1)
-}
-
-func (l *defaultLogger) Log(ctx context.Context, level Level, args ...interface{}) {
-	if !l.V(level) {
-		return
-	}
-
-	l.RLock()
-	fields := copyFields(l.opts.Fields)
-	l.RUnlock()
-
-	fields = append(fields, "level", level.String())
-
-	if _, file, line, ok := runtime.Caller(l.opts.CallerSkipCount); ok {
-		fields = append(fields, "caller", fmt.Sprintf("%s:%d", logCallerfilePath(file), line))
-	}
-	fields = append(fields, "timestamp", time.Now().Format("2006-01-02 15:04:05"))
-
-	if len(args) > 0 {
-		fields = append(fields, "msg", fmt.Sprint(args...))
-	}
-
-	out := make(map[string]interface{}, len(fields)/2)
-	for i := 0; i < len(fields); i += 2 {
-		out[fields[i].(string)] = fields[i+1]
-	}
-	l.RLock()
-	_ = l.enc.Encode(out)
-	l.RUnlock()
-}
-
-func (l *defaultLogger) Logf(ctx context.Context, level Level, msg string, args ...interface{}) {
-	if !l.V(level) {
-		return
-	}
-
-	l.RLock()
-	fields := copyFields(l.opts.Fields)
-	l.RUnlock()
-
-	fields = append(fields, "level", level.String())
-
-	if _, file, line, ok := runtime.Caller(l.opts.CallerSkipCount); ok {
-		fields = append(fields, "caller", fmt.Sprintf("%s:%d", logCallerfilePath(file), line))
-	}
-
-	fields = append(fields, "timestamp", time.Now().Format("2006-01-02 15:04:05"))
-	if len(args) > 0 {
-		fields = append(fields, "msg", fmt.Sprintf(msg, args...))
-	} else if msg != "" {
-		fields = append(fields, "msg", msg)
-	}
-
-	out := make(map[string]interface{}, len(fields)/2)
-	for i := 0; i < len(fields); i += 2 {
-		out[fields[i].(string)] = fields[i+1]
-	}
-	l.RLock()
-	_ = l.enc.Encode(out)
-	l.RUnlock()
-}
-
-func (l *defaultLogger) Options() Options {
-	return l.opts
-}
-
-// NewLogger builds a new logger based on options
-func NewLogger(opts ...Option) Logger {
-	l := &defaultLogger{
-		opts: NewOptions(opts...),
-	}
-	l.enc = json.NewEncoder(l.opts.Out)
-	return l
-}

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/noop.go

@@ -0,0 +1,90 @@
+package logger
+
+import (
+	"context"
+)
+
+type noopLogger struct {
+	opts Options
+}
+
+func NewLogger(opts ...Option) Logger {
+	options := NewOptions(opts...)
+	return &noopLogger{opts: options}
+}
+
+func (l *noopLogger) V(lvl Level) bool {
+	return false
+}
+
+func (l *noopLogger) Level(lvl Level) {
+}
+
+func (l *noopLogger) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&l.opts)
+	}
+	return nil
+}
+
+func (l *noopLogger) Clone(opts ...Option) Logger {
+	nl := &noopLogger{opts: l.opts}
+	for _, o := range opts {
+		o(&nl.opts)
+	}
+	return nl
+}
+
+func (l *noopLogger) Fields(attrs ...interface{}) Logger {
+	return l
+}
+
+func (l *noopLogger) Options() Options {
+	return l.opts
+}
+
+func (l *noopLogger) String() string {
+	return "noop"
+}
+
+func (l *noopLogger) Log(ctx context.Context, lvl Level, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Info(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Debug(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Error(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Trace(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Warn(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Fatal(ctx context.Context, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Logf(ctx context.Context, lvl Level, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Infof(ctx context.Context, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Debugf(ctx context.Context, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Errorf(ctx context.Context, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Tracef(ctx context.Context, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Warnf(ctx context.Context, msg string, attrs ...interface{}) {
+}
+
+func (l *noopLogger) Fatalf(ctx context.Context, msg string, attrs ...interface{}) {
+}

logger/slog/options.go

@@ -0,0 +1,27 @@
+package slog
+
+import "go.unistack.org/micro/v3/logger"
+
+type sourceKey struct{}
+
+func WithSourceKey(v string) logger.Option {
+	return logger.SetOption(sourceKey{}, v)
+}
+
+type timeKey struct{}
+
+func WithTimeKey(v string) logger.Option {
+	return logger.SetOption(timeKey{}, v)
+}
+
+type messageKey struct{}
+
+func WithMessageKey(v string) logger.Option {
+	return logger.SetOption(messageKey{}, v)
+}
+
+type levelKey struct{}
+
+func WithLevelKey(v string) logger.Option {
+	return logger.SetOption(levelKey{}, v)
+}

logger/slog/slog.go

@@ -0,0 +1,419 @@
+package slog
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"os"
+	"runtime"
+	"strconv"
+	"time"
+
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/tracer"
+)
+
+var (
+	DefaultSourceKey  string = slog.SourceKey
+	DefaultTimeKey    string = slog.TimeKey
+	DefaultMessageKey string = slog.MessageKey
+	DefaultLevelKey   string = slog.LevelKey
+)
+
+var (
+	traceValue = slog.StringValue("trace")
+	debugValue = slog.StringValue("debug")
+	infoValue  = slog.StringValue("info")
+	warnValue  = slog.StringValue("warn")
+	errorValue = slog.StringValue("error")
+	fatalValue = slog.StringValue("fatal")
+)
+
+func (s *slogLogger) renameAttr(_ []string, a slog.Attr) slog.Attr {
+	switch a.Key {
+	case slog.SourceKey:
+		source := a.Value.Any().(*slog.Source)
+		a.Value = slog.StringValue(source.File + ":" + strconv.Itoa(source.Line))
+		a.Key = s.sourceKey
+	case slog.TimeKey:
+		a.Key = s.timeKey
+	case slog.MessageKey:
+		a.Key = s.messageKey
+	case slog.LevelKey:
+		level := a.Value.Any().(slog.Level)
+		lvl := slogToLoggerLevel(level)
+		a.Key = s.levelKey
+		switch {
+		case lvl < logger.DebugLevel:
+			a.Value = traceValue
+		case lvl < logger.InfoLevel:
+			a.Value = debugValue
+		case lvl < logger.WarnLevel:
+			a.Value = infoValue
+		case lvl < logger.ErrorLevel:
+			a.Value = warnValue
+		case lvl < logger.FatalLevel:
+			a.Value = errorValue
+		case lvl >= logger.FatalLevel:
+			a.Value = fatalValue
+		default:
+			a.Value = infoValue
+		}
+	}
+
+	return a
+}
+
+type slogLogger struct {
+	slog       *slog.Logger
+	leveler    *slog.LevelVar
+	levelKey   string
+	messageKey string
+	sourceKey  string
+	timeKey    string
+	opts       logger.Options
+}
+
+func (s *slogLogger) Clone(opts ...logger.Option) logger.Logger {
+	options := s.opts
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	l := &slogLogger{
+		opts:       options,
+		levelKey:   s.levelKey,
+		messageKey: s.messageKey,
+		sourceKey:  s.sourceKey,
+		timeKey:    s.timeKey,
+	}
+
+	if v, ok := l.opts.Context.Value(levelKey{}).(string); ok && v != "" {
+		l.levelKey = v
+	}
+	if v, ok := l.opts.Context.Value(messageKey{}).(string); ok && v != "" {
+		l.messageKey = v
+	}
+	if v, ok := l.opts.Context.Value(sourceKey{}).(string); ok && v != "" {
+		l.sourceKey = v
+	}
+	if v, ok := l.opts.Context.Value(timeKey{}).(string); ok && v != "" {
+		l.timeKey = v
+	}
+
+	l.leveler = new(slog.LevelVar)
+	handleOpt := &slog.HandlerOptions{
+		ReplaceAttr: s.renameAttr,
+		Level:       l.leveler,
+		AddSource:   true,
+	}
+	l.leveler.Set(loggerToSlogLevel(l.opts.Level))
+	handler := slog.NewJSONHandler(options.Out, handleOpt)
+	l.slog = slog.New(handler).With(options.Fields...)
+
+	return l
+}
+
+func (s *slogLogger) V(level logger.Level) bool {
+	return s.opts.Level.Enabled(level)
+}
+
+func (s *slogLogger) Level(level logger.Level) {
+	s.leveler.Set(loggerToSlogLevel(level))
+}
+
+func (s *slogLogger) Options() logger.Options {
+	return s.opts
+}
+
+func (s *slogLogger) Fields(attrs ...interface{}) logger.Logger {
+	nl := &slogLogger{
+		opts:       s.opts,
+		levelKey:   s.levelKey,
+		messageKey: s.messageKey,
+		sourceKey:  s.sourceKey,
+		timeKey:    s.timeKey,
+	}
+	nl.leveler = new(slog.LevelVar)
+	nl.leveler.Set(s.leveler.Level())
+
+	handleOpt := &slog.HandlerOptions{
+		ReplaceAttr: nl.renameAttr,
+		Level:       s.leveler,
+		AddSource:   true,
+	}
+
+	handler := slog.NewJSONHandler(s.opts.Out, handleOpt)
+	nl.slog = slog.New(handler).With(attrs...)
+
+	return nl
+}
+
+func (s *slogLogger) Init(opts ...logger.Option) error {
+	for _, o := range opts {
+		o(&s.opts)
+	}
+
+	if v, ok := s.opts.Context.Value(levelKey{}).(string); ok && v != "" {
+		s.levelKey = v
+	}
+	if v, ok := s.opts.Context.Value(messageKey{}).(string); ok && v != "" {
+		s.messageKey = v
+	}
+	if v, ok := s.opts.Context.Value(sourceKey{}).(string); ok && v != "" {
+		s.sourceKey = v
+	}
+	if v, ok := s.opts.Context.Value(timeKey{}).(string); ok && v != "" {
+		s.timeKey = v
+	}
+
+	s.leveler = new(slog.LevelVar)
+	handleOpt := &slog.HandlerOptions{
+		ReplaceAttr: s.renameAttr,
+		Level:       s.leveler,
+		AddSource:   true,
+	}
+	s.leveler.Set(loggerToSlogLevel(s.opts.Level))
+	handler := slog.NewJSONHandler(s.opts.Out, handleOpt)
+	s.slog = slog.New(handler).With(s.opts.Fields...)
+
+	slog.SetDefault(s.slog)
+
+	return nil
+}
+
+func (s *slogLogger) Log(ctx context.Context, lvl logger.Level, attrs ...interface{}) {
+	if !s.V(lvl) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), loggerToSlogLevel(lvl), fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Logf(ctx context.Context, lvl logger.Level, msg string, attrs ...interface{}) {
+	if !s.V(lvl) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), loggerToSlogLevel(lvl), fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Info(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.InfoLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelInfo, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Infof(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.InfoLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelInfo, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Debug(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.DebugLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelDebug, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Debugf(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.DebugLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelDebug, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Trace(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.TraceLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelDebug-1, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Tracef(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.TraceLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelDebug-1, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Error(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.ErrorLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelError, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	//	r.Add(attrs[1:]...)
+	r.Attrs(func(a slog.Attr) bool {
+		if a.Key == "error" {
+			if span, ok := tracer.SpanFromContext(ctx); ok {
+				span.SetStatus(tracer.SpanStatusError, a.Value.String())
+				return false
+			}
+		}
+		return true
+	})
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Errorf(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.ErrorLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelError, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	r.Attrs(func(a slog.Attr) bool {
+		if a.Key == "error" {
+			if span, ok := tracer.SpanFromContext(ctx); ok {
+				span.SetStatus(tracer.SpanStatusError, a.Value.String())
+				return false
+			}
+		}
+		return true
+	})
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Fatal(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.FatalLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelError+1, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+	os.Exit(1)
+}
+
+func (s *slogLogger) Fatalf(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.FatalLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelError+1, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+	os.Exit(1)
+}
+
+func (s *slogLogger) Warn(ctx context.Context, attrs ...interface{}) {
+	if !s.V(logger.WarnLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelWarn, fmt.Sprintf("%s", attrs[0]), pcs[0])
+	// r.Add(attrs[1:]...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) Warnf(ctx context.Context, msg string, attrs ...interface{}) {
+	if !s.V(logger.WarnLevel) {
+		return
+	}
+	var pcs [1]uintptr
+	runtime.Callers(s.opts.CallerSkipCount, pcs[:]) // skip [Callers, Infof]
+	r := slog.NewRecord(time.Now(), slog.LevelWarn, fmt.Sprintf(msg, attrs...), pcs[0])
+	// r.Add(attrs...)
+	_ = s.slog.Handler().Handle(ctx, r)
+}
+
+func (s *slogLogger) String() string {
+	return "slog"
+}
+
+func NewLogger(opts ...logger.Option) logger.Logger {
+	s := &slogLogger{
+		opts:       logger.NewOptions(opts...),
+		sourceKey:  DefaultSourceKey,
+		timeKey:    DefaultTimeKey,
+		messageKey: DefaultMessageKey,
+		levelKey:   DefaultLevelKey,
+	}
+	if v, ok := s.opts.Context.Value(levelKey{}).(string); ok && v != "" {
+		s.levelKey = v
+	}
+	if v, ok := s.opts.Context.Value(messageKey{}).(string); ok && v != "" {
+		s.messageKey = v
+	}
+	if v, ok := s.opts.Context.Value(sourceKey{}).(string); ok && v != "" {
+		s.sourceKey = v
+	}
+	if v, ok := s.opts.Context.Value(timeKey{}).(string); ok && v != "" {
+		s.timeKey = v
+	}
+	return s
+}
+
+func loggerToSlogLevel(level logger.Level) slog.Level {
+	switch level {
+	case logger.DebugLevel:
+		return slog.LevelDebug
+	case logger.WarnLevel:
+		return slog.LevelWarn
+	case logger.ErrorLevel:
+		return slog.LevelError
+	case logger.TraceLevel:
+		return slog.LevelDebug - 1
+	case logger.FatalLevel:
+		return slog.LevelError + 1
+	default:
+		return slog.LevelInfo
+	}
+}
+
+func slogToLoggerLevel(level slog.Level) logger.Level {
+	switch level {
+	case slog.LevelDebug:
+		return logger.DebugLevel
+	case slog.LevelWarn:
+		return logger.WarnLevel
+	case slog.LevelError:
+		return logger.ErrorLevel
+	case slog.LevelDebug - 1:
+		return logger.TraceLevel
+	case slog.LevelError + 1:
+		return logger.FatalLevel
+	default:
+		return logger.InfoLevel
+	}
+}

logger/slog/slog_test.go

@@ -0,0 +1,141 @@
+package slog
+
+import (
+	"bytes"
+	"context"
+	"log"
+	"testing"
+
+	"go.unistack.org/micro/v3/logger"
+)
+
+func TestContext(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	nl, ok := logger.FromContext(logger.NewContext(ctx, l.Fields("key", "val")))
+	if !ok {
+		t.Fatal("context without logger")
+	}
+	nl.Info(ctx, "message")
+	if !bytes.Contains(buf.Bytes(), []byte(`"key":"val"`)) {
+		t.Fatalf("logger fields not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestFields(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	nl := l.Fields("key", "val")
+
+	nl.Info(ctx, "message")
+	if !bytes.Contains(buf.Bytes(), []byte(`"key":"val"`)) {
+		t.Fatalf("logger fields not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestFromContextWithFields(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	var ok bool
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	nl := l.Fields("key", "val")
+
+	ctx = logger.NewContext(ctx, nl)
+
+	l, ok = logger.FromContext(ctx)
+	if !ok {
+		t.Fatalf("context does not have logger")
+	}
+
+	l.Info(ctx, "message")
+	if !bytes.Contains(buf.Bytes(), []byte(`"key":"val"`)) {
+		t.Fatalf("logger fields not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestClone(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	nl := l.Clone(logger.WithLevel(logger.ErrorLevel))
+	if err := nl.Init(); err != nil {
+		t.Fatal(err)
+	}
+	nl.Info(ctx, "info message")
+	if len(buf.Bytes()) != 0 {
+		t.Fatal("message must not be logged")
+	}
+	l.Info(ctx, "info message")
+	if len(buf.Bytes()) == 0 {
+		t.Fatal("message must be logged")
+	}
+}
+
+func TestRedirectStdLogger(t *testing.T) {
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	fn := logger.RedirectStdLogger(l, logger.ErrorLevel)
+	defer fn()
+	log.Print("test")
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"error"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"test"`))) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+}
+
+func TestStdLogger(t *testing.T) {
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	lg := logger.NewStdLogger(l, logger.ErrorLevel)
+	lg.Print("test")
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"error"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"test"`))) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+}
+
+func TestLogger(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.TraceLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	l.Trace(ctx, "trace_msg1")
+	l.Warn(ctx, "warn_msg1")
+	l.Fields("error", "test").Info(ctx, "error message")
+	l.Warn(ctx, "first second")
+
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"trace"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"trace_msg1"`))) {
+		t.Fatalf("logger tracer, buf %s", buf.Bytes())
+	}
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"warn"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"warn_msg1"`))) {
+		t.Fatalf("logger warn, buf %s", buf.Bytes())
+	}
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"info"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"error message","error":"test"`))) {
+		t.Fatalf("logger info, buf %s", buf.Bytes())
+	}
+	if !(bytes.Contains(buf.Bytes(), []byte(`"level":"warn"`)) && bytes.Contains(buf.Bytes(), []byte(`"msg":"first second"`))) {
+		t.Fatalf("logger warn, buf %s", buf.Bytes())
+	}
+}

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/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

@@ -1,16 +1,49 @@
-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 (
+	// ClientRequestDurationSeconds specifies meter metric name
+	ClientRequestDurationSeconds = "client_request_duration_seconds"
+	// ClientRequestLatencyMicroseconds specifies meter metric name
+	ClientRequestLatencyMicroseconds = "client_request_latency_microseconds"
+	// ClientRequestTotal specifies meter metric name
+	ClientRequestTotal = "client_request_total"
+	// ClientRequestInflight specifies meter metric name
+	ClientRequestInflight = "client_request_inflight"
+	// ServerRequestDurationSeconds specifies meter metric name
+	ServerRequestDurationSeconds = "server_request_duration_seconds"
+	// ServerRequestLatencyMicroseconds specifies meter metric name
+	ServerRequestLatencyMicroseconds = "server_request_latency_microseconds"
+	// ServerRequestTotal specifies meter metric name
+	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"
 	labelStatus   = "status"
@@ -197,7 +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
@@ -239,3 +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
@@ -90,7 +90,33 @@ type Option func(*Options) error
 // Broker to be used for client and server
 func Broker(b broker.Broker, opts ...BrokerOption) Option {
 	return func(o *Options) error {
-		o.Brokers = []broker.Broker{b}
+		var err error
+		bopts := brokerOptions{}
+		for _, opt := range opts {
+			opt(&bopts)
+		}
+		all := false
+		if len(opts) == 0 {
+			all = true
+		}
+		for _, srv := range o.Servers {
+			for _, os := range bopts.servers {
+				if srv.Name() == os || all {
+					if err = srv.Init(server.Broker(b)); err != nil {
+						return err
+					}
+				}
+			}
+		}
+		for _, cli := range o.Clients {
+			for _, oc := range bopts.clients {
+				if cli.Name() == oc || all {
+					if err = cli.Init(client.Broker(b)); err != nil {
+						return err
+					}
+				}
+			}
+		}
 		return nil
 	}
 }

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/context.go

@@ -33,6 +33,16 @@ func SetOption(k, v interface{}) Option {
 	}
 }
 
+// SetSubscriberOption returns a function to setup a context with given value
+func SetSubscriberOption(k, v interface{}) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}
+
 // SetHandlerOption returns a function to setup a context with given value
 func SetHandlerOption(k, v interface{}) HandlerOption {
 	return func(o *HandlerOptions) {

server/context_test.go

@@ -51,3 +51,14 @@ func TestSetOption(t *testing.T) {
 		t.Fatal("SetOption not works")
 	}
 }
+
+func TestSetSubscriberOption(t *testing.T) {
+	type key struct{}
+	o := SetSubscriberOption(key{}, "test")
+	opts := &SubscriberOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetSubscriberOption not works")
+	}
+}

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

@@ -0,0 +1,59 @@
+package server
+
+import (
+	"reflect"
+
+	"go.unistack.org/micro/v3/register"
+)
+
+type rpcHandler struct {
+	opts      HandlerOptions
+	handler   interface{}
+	name      string
+	endpoints []*register.Endpoint
+}
+
+func newRPCHandler(handler interface{}, opts ...HandlerOption) Handler {
+	options := NewHandlerOptions(opts...)
+
+	typ := reflect.TypeOf(handler)
+	hdlr := reflect.ValueOf(handler)
+	name := reflect.Indirect(hdlr).Type().Name()
+
+	var endpoints []*register.Endpoint
+
+	for m := 0; m < typ.NumMethod(); m++ {
+		if e := register.ExtractEndpoint(typ.Method(m)); e != nil {
+			e.Name = name + "." + e.Name
+
+			for k, v := range options.Metadata[e.Name] {
+				e.Metadata[k] = v
+			}
+
+			endpoints = append(endpoints, e)
+		}
+	}
+
+	return &rpcHandler{
+		name:      name,
+		handler:   handler,
+		endpoints: endpoints,
+		opts:      options,
+	}
+}
+
+func (r *rpcHandler) Name() string {
+	return r.name
+}
+
+func (r *rpcHandler) Handler() interface{} {
+	return r.handler
+}
+
+func (r *rpcHandler) Endpoints() []*register.Endpoint {
+	return r.endpoints
+}
+
+func (r *rpcHandler) Options() HandlerOptions {
+	return r.opts
+}

server/noop.go

@@ -1,17 +1,18 @@
 package server
 
 import (
-	"reflect"
+	"fmt"
 	"sort"
 	"sync"
 	"time"
 
-	"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
@@ -24,12 +25,13 @@ const (
 )
 
 type noopServer struct {
-	h        Handler
-	wg       *sync.WaitGroup
-	rsvc     *register.Service
-	handlers map[string]Handler
-	exit     chan chan error
-	opts     Options
+	h           Handler
+	wg          *sync.WaitGroup
+	rsvc        *register.Service
+	handlers    map[string]Handler
+	subscribers map[*subscriber][]broker.Subscriber
+	exit        chan chan error
+	opts        Options
 	sync.RWMutex
 	registered bool
 	started    bool
@@ -41,6 +43,9 @@ func NewServer(opts ...Option) Server {
 	if n.handlers == nil {
 		n.handlers = make(map[string]Handler)
 	}
+	if n.subscribers == nil {
+		n.subscribers = make(map[*subscriber][]broker.Subscriber)
+	}
 	if n.exit == nil {
 		n.exit = make(chan chan error)
 	}
@@ -66,10 +71,37 @@ func (n *noopServer) Name() string {
 	return n.opts.Name
 }
 
+func (n *noopServer) Subscribe(sb Subscriber) error {
+	sub, ok := sb.(*subscriber)
+	if !ok {
+		return fmt.Errorf("invalid subscriber: expected *subscriber")
+	} else if len(sub.handlers) == 0 {
+		return fmt.Errorf("invalid subscriber: no handler functions")
+	}
+
+	if err := ValidateSubscriber(sb); err != nil {
+		return err
+	}
+
+	n.Lock()
+	if _, ok = n.subscribers[sub]; ok {
+		n.Unlock()
+		return fmt.Errorf("subscriber %v already exists", sub)
+	}
+
+	n.subscribers[sub] = nil
+	n.Unlock()
+	return nil
+}
+
 func (n *noopServer) NewHandler(h interface{}, opts ...HandlerOption) Handler {
 	return newRPCHandler(h, opts...)
 }
 
+func (n *noopServer) NewSubscriber(topic string, sb interface{}, opts ...SubscriberOption) Subscriber {
+	return newSubscriber(topic, sb, opts...)
+}
+
 func (n *noopServer) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
@@ -78,6 +110,9 @@ func (n *noopServer) Init(opts ...Option) error {
 	if n.handlers == nil {
 		n.handlers = make(map[string]Handler, 1)
 	}
+	if n.subscribers == nil {
+		n.subscribers = make(map[*subscriber][]broker.Subscriber, 1)
+	}
 
 	if n.exit == nil {
 		n.exit = make(chan chan error)
@@ -123,10 +158,21 @@ func (n *noopServer) Register() error {
 
 	sort.Strings(handlerList)
 
-	endpoints := make([]*register.Endpoint, 0, len(handlerList))
+	subscriberList := make([]*subscriber, 0, len(n.subscribers))
+	for e := range n.subscribers {
+		subscriberList = append(subscriberList, e)
+	}
+	sort.Slice(subscriberList, func(i, j int) bool {
+		return subscriberList[i].topic > subscriberList[j].topic
+	})
+
+	endpoints := make([]*register.Endpoint, 0, len(handlerList)+len(subscriberList))
 	for _, h := range handlerList {
 		endpoints = append(endpoints, n.handlers[h].Endpoints()...)
 	}
+	for _, e := range subscriberList {
+		endpoints = append(endpoints, e.Endpoints()...)
+	}
 	n.RUnlock()
 
 	service.Nodes[0].Metadata["protocol"] = "noop"
@@ -194,6 +240,33 @@ func (n *noopServer) Deregister() error {
 
 	n.registered = false
 
+	cx := config.Context
+
+	wg := sync.WaitGroup{}
+	for sb, subs := range n.subscribers {
+		for idx := range subs {
+			if sb.Options().Context != nil {
+				cx = sb.Options().Context
+			}
+
+			ncx := cx
+			wg.Add(1)
+			go func(s broker.Subscriber) {
+				defer wg.Done()
+				if config.Logger.V(logger.InfoLevel) {
+					config.Logger.Infof(n.opts.Context, "unsubscribing from topic: %s", s.Topic())
+				}
+				if err := s.Unsubscribe(ncx); err != nil {
+					if config.Logger.V(logger.ErrorLevel) {
+						config.Logger.Errorf(n.opts.Context, "unsubscribing from topic: %s err: %v", s.Topic(), err)
+					}
+				}
+			}(subs[idx])
+		}
+		n.subscribers[sb] = nil
+	}
+	wg.Wait()
+
 	n.Unlock()
 	return nil
 }
@@ -230,6 +303,21 @@ func (n *noopServer) Start() error {
 	}
 	n.Unlock()
 
+	// only connect if we're subscribed
+	if len(n.subscribers) > 0 {
+		// connect to the broker
+		if err := config.Broker.Connect(config.Context); err != nil {
+			if config.Logger.V(logger.ErrorLevel) {
+				config.Logger.Errorf(n.opts.Context, "broker [%s] connect error: %v", config.Broker.String(), err)
+			}
+			return err
+		}
+
+		if config.Logger.V(logger.InfoLevel) {
+			config.Logger.Infof(n.opts.Context, "broker [%s] Connected to %s", config.Broker.String(), config.Broker.Address())
+		}
+	}
+
 	// use RegisterCheck func before register
 	// nolint: nestif
 	if err := config.RegisterCheck(config.Context); err != nil {
@@ -245,6 +333,10 @@ func (n *noopServer) Start() error {
 		}
 	}
 
+	if err := n.subscribe(); err != nil {
+		return err
+	}
+
 	go func() {
 		t := new(time.Ticker)
 
@@ -308,6 +400,16 @@ func (n *noopServer) Start() error {
 
 		// close transport
 		ch <- nil
+
+		if config.Logger.V(logger.InfoLevel) {
+			config.Logger.Infof(n.opts.Context, "broker [%s] Disconnected from %s", config.Broker.String(), config.Broker.Address())
+		}
+		// disconnect broker
+		if err := config.Broker.Disconnect(config.Context); err != nil {
+			if config.Logger.V(logger.ErrorLevel) {
+				config.Logger.Errorf(n.opts.Context, "broker [%s] disconnect error: %v", config.Broker.String(), err)
+			}
+		}
 	}()
 
 	// mark the server as started
@@ -318,6 +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 {
@@ -337,55 +478,3 @@ func (n *noopServer) Stop() error {
 
 	return err
 }
-
-type rpcHandler struct {
-	opts      HandlerOptions
-	handler   interface{}
-	name      string
-	endpoints []*register.Endpoint
-}
-
-func newRPCHandler(handler interface{}, opts ...HandlerOption) Handler {
-	options := NewHandlerOptions(opts...)
-
-	typ := reflect.TypeOf(handler)
-	hdlr := reflect.ValueOf(handler)
-	name := reflect.Indirect(hdlr).Type().Name()
-
-	var endpoints []*register.Endpoint
-
-	for m := 0; m < typ.NumMethod(); m++ {
-		if e := register.ExtractEndpoint(typ.Method(m)); e != nil {
-			e.Name = name + "." + e.Name
-
-			for k, v := range options.Metadata[e.Name] {
-				e.Metadata[k] = v
-			}
-
-			endpoints = append(endpoints, e)
-		}
-	}
-
-	return &rpcHandler{
-		name:      name,
-		handler:   handler,
-		endpoints: endpoints,
-		opts:      options,
-	}
-}
-
-func (r *rpcHandler) Name() string {
-	return r.name
-}
-
-func (r *rpcHandler) Handler() interface{} {
-	return r.handler
-}
-
-func (r *rpcHandler) Endpoints() []*register.Endpoint {
-	return r.endpoints
-}
-
-func (r *rpcHandler) Options() HandlerOptions {
-	return r.opts
-}

server/noop_test.go

@@ -0,0 +1,104 @@
+package server_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"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 {
+	t *testing.T
+}
+
+type TestMessage struct {
+	Name string
+}
+
+func (h *TestHandler) SingleSubHandler(ctx context.Context, msg *codec.Frame) error {
+	// fmt.Printf("msg %s\n", msg.Data)
+	return nil
+}
+
+func (h *TestHandler) BatchSubHandler(ctxs []context.Context, msgs []*codec.Frame) error {
+	if len(msgs) != 8 {
+		h.t.Fatal("invalid number of messages received")
+	}
+	for idx := 0; idx < len(msgs); idx++ {
+		md, _ := metadata.FromIncomingContext(ctxs[idx])
+		_ = md
+		//	fmt.Printf("msg md %v\n", md)
+	}
+	return nil
+}
+
+func TestNoopSub(t *testing.T) {
+	ctx := context.Background()
+
+	b := broker.NewBroker()
+
+	if err := b.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := b.Connect(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	logger.DefaultLogger.Init(logger.WithLevel(logger.ErrorLevel))
+	s := server.NewServer(
+		server.Broker(b),
+		server.Codec("application/octet-stream", codec.NewCodec()),
+	)
+	if err := s.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	c := client.NewClient(
+		client.Broker(b),
+		client.Codec("application/octet-stream", codec.NewCodec()),
+		client.ContentType("application/octet-stream"),
+	)
+	if err := c.Init(); err != nil {
+		t.Fatal(err)
+	}
+	h := &TestHandler{t: t}
+
+	if err := s.Subscribe(s.NewSubscriber("single_topic", h.SingleSubHandler,
+		server.SubscriberQueue("queue"),
+	)); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := s.Subscribe(s.NewSubscriber("batch_topic", h.BatchSubHandler,
+		server.SubscriberQueue("queue"),
+		server.SubscriberBatch(true),
+	)); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := s.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	msgs := make([]client.Message, 0, 8)
+	for i := 0; i < 8; i++ {
+		msgs = append(msgs, c.NewMessage("batch_topic", &codec.Frame{Data: []byte(fmt.Sprintf(`{"name": "test_name %d"}`, i))}))
+	}
+
+	if err := c.BatchPublish(ctx, msgs); err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if err := s.Stop(); err != nil {
+			t.Fatal(err)
+		}
+	}()
+}

server/options.go

@@ -7,26 +7,16 @@ import (
 	"sync"
 	"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/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"
-)
-
-var (
-	// ServerRequestDurationSeconds specifies meter metric name
-	ServerRequestDurationSeconds = "server_request_duration_seconds"
-	// ServerRequestLatencyMicroseconds specifies meter metric name
-	ServerRequestLatencyMicroseconds = "server_request_latency_microseconds"
-	// ServerRequestTotal specifies meter metric name
-	ServerRequestTotal = "server_request_total"
-	// ServerRequestInflight specifies meter metric name
-	ServerRequestInflight = "server_request_inflight"
+	"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
@@ -36,6 +26,8 @@ type Option func(*Options)
 type Options struct {
 	// Context holds the external options and can be used for server shutdown
 	Context context.Context
+	// Broker holds the server broker
+	Broker broker.Broker
 	// Register holds the register
 	Register register.Register
 	// Tracer holds the tracer
@@ -46,6 +38,12 @@ type Options struct {
 	Meter meter.Meter
 	// Transport holds the transport
 	Transport transport.Transport
+
+	/*
+		// Router for requests
+		Router Router
+	*/
+
 	// Listener may be passed if already created
 	Listener net.Listener
 	// Wait group
@@ -70,6 +68,10 @@ type Options struct {
 	Advertise string
 	// Version holds the server version
 	Version string
+	// SubWrappers holds the server subscribe wrappers
+	SubWrappers []SubscriberWrapper
+	// BatchSubWrappers holds the server batch subscribe wrappers
+	BatchSubWrappers []BatchSubscriberWrapper
 	// HdlrWrappers holds the handler wrappers
 	HdlrWrappers []HandlerWrapper
 	// RegisterAttempts holds the number of register attempts before error
@@ -82,7 +84,7 @@ type Options struct {
 	MaxConn int
 	// DeregisterAttempts holds the number of deregister attempts before error
 	DeregisterAttempts int
-	// Hooks may contains HandlerWrapper or Server func wrapper
+	// Hooks may contains SubscriberWrapper, HandlerWrapper or Server func wrapper
 	Hooks options.Hooks
 }
 
@@ -98,6 +100,7 @@ func NewOptions(opts ...Option) Options {
 		Logger:           logger.DefaultLogger,
 		Meter:            meter.DefaultMeter,
 		Tracer:           tracer.DefaultTracer,
+		Broker:           broker.DefaultBroker,
 		Register:         register.DefaultRegister,
 		Transport:        transport.DefaultTransport,
 		Address:          DefaultAddress,
@@ -170,6 +173,13 @@ func Advertise(a string) Option {
 	}
 }
 
+// Broker to use for pub/sub
+func Broker(b broker.Broker) Option {
+	return func(o *Options) {
+		o.Broker = b
+	}
+}
+
 // Codec to use to encode/decode requests for a given content type
 func Codec(contentType string, c codec.Codec) Option {
 	return func(o *Options) {
@@ -251,6 +261,15 @@ func TLSConfig(t *tls.Config) Option {
 	}
 }
 
+/*
+// WithRouter sets the request router
+func WithRouter(r Router) Option {
+	return func(o *Options) {
+		o.Router = r
+	}
+}
+*/
+
 // Wait tells the server to wait for requests to finish before exiting
 // If `wg` is nil, server only wait for completion of rpc handler.
 // For user need finer grained control, pass a concrete `wg` here, server will
@@ -271,6 +290,20 @@ func WrapHandler(w HandlerWrapper) Option {
 	}
 }
 
+// WrapSubscriber adds a subscriber Wrapper to a list of options passed into the server
+func WrapSubscriber(w SubscriberWrapper) Option {
+	return func(o *Options) {
+		o.SubWrappers = append(o.SubWrappers, w)
+	}
+}
+
+// WrapBatchSubscriber adds a batch subscriber Wrapper to a list of options passed into the server
+func WrapBatchSubscriber(w BatchSubscriberWrapper) Option {
+	return func(o *Options) {
+		o.BatchSubWrappers = append(o.BatchSubWrappers, w)
+	}
+}
+
 // MaxConn specifies maximum number of max simultaneous connections to server
 func MaxConn(n int) Option {
 	return func(o *Options) {
@@ -310,6 +343,41 @@ func NewHandlerOptions(opts ...HandlerOption) HandlerOptions {
 	return options
 }
 
+// SubscriberOption func
+type SubscriberOption func(*SubscriberOptions)
+
+// SubscriberOptions struct
+type SubscriberOptions struct {
+	// Context holds the external options
+	Context context.Context
+	// Queue holds the subscription queue
+	Queue string
+	// AutoAck flag for auto ack messages after processing
+	AutoAck bool
+	// BodyOnly flag specifies that message without headers
+	BodyOnly bool
+	// Batch flag specifies that message processed in batches
+	Batch bool
+	// BatchSize flag specifies max size of batch
+	BatchSize int
+	// BatchWait flag specifies max wait time for batch filling
+	BatchWait time.Duration
+}
+
+// NewSubscriberOptions create new SubscriberOptions
+func NewSubscriberOptions(opts ...SubscriberOption) SubscriberOptions {
+	options := SubscriberOptions{
+		AutoAck: true,
+		Context: context.Background(),
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return options
+}
+
 // EndpointMetadata is a Handler option that allows metadata to be added to
 // individual endpoints.
 func EndpointMetadata(name string, md metadata.Metadata) HandlerOption {
@@ -317,3 +385,68 @@ func EndpointMetadata(name string, md metadata.Metadata) HandlerOption {
 		o.Metadata[name] = metadata.Copy(md)
 	}
 }
+
+// DisableAutoAck will disable auto acking of messages
+// after they have been handled.
+func DisableAutoAck() SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.AutoAck = false
+	}
+}
+
+// SubscriberQueue sets the shared queue name distributed messages across subscribers
+func SubscriberQueue(n string) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.Queue = n
+	}
+}
+
+// SubscriberGroup sets the shared group name distributed messages across subscribers
+func SubscriberGroup(n string) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.Queue = n
+	}
+}
+
+// SubscriberBodyOnly says broker that message contains raw data with absence of micro broker.Message format
+func SubscriberBodyOnly(b bool) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.BodyOnly = b
+	}
+}
+
+// SubscriberContext set context options to allow broker SubscriberOption passed
+func SubscriberContext(ctx context.Context) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.Context = ctx
+	}
+}
+
+// SubscriberAck control auto ack processing for handler
+func SubscriberAck(b bool) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.AutoAck = b
+	}
+}
+
+// SubscriberBatch control batch processing for handler
+func SubscriberBatch(b bool) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.Batch = b
+	}
+}
+
+// SubscriberBatchSize control batch filling size for handler
+// Batch filling max waiting time controlled by SubscriberBatchWait
+func SubscriberBatchSize(n int) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.BatchSize = n
+	}
+}
+
+// SubscriberBatchWait control batch filling wait time for handler
+func SubscriberBatchWait(td time.Duration) SubscriberOption {
+	return func(o *SubscriberOptions) {
+		o.BatchWait = td
+	}
+}

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 (
@@ -78,6 +78,7 @@ func NewRegisterService(s Server) (*register.Service, error) {
 	node.Metadata = metadata.Copy(opts.Metadata)
 
 	node.Metadata["server"] = s.String()
+	node.Metadata["broker"] = opts.Broker.String()
 	node.Metadata["register"] = opts.Register.String()
 
 	return &register.Service{

server/request.go

@@ -0,0 +1,35 @@
+package server
+
+import (
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
+)
+
+type rpcMessage struct {
+	payload     interface{}
+	codec       codec.Codec
+	header      metadata.Metadata
+	topic       string
+	contentType string
+	body        []byte
+}
+
+func (r *rpcMessage) ContentType() string {
+	return r.contentType
+}
+
+func (r *rpcMessage) Topic() string {
+	return r.topic
+}
+
+func (r *rpcMessage) Body() interface{} {
+	return r.payload
+}
+
+func (r *rpcMessage) Header() metadata.Metadata {
+	return r.header
+}
+
+func (r *rpcMessage) Codec() codec.Codec {
+	return r.codec
+}

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
@@ -48,6 +48,10 @@ type Server interface {
 	Handle(h Handler) error
 	// Create a new handler
 	NewHandler(h interface{}, opts ...HandlerOption) Handler
+	// Create a new subscriber
+	NewSubscriber(topic string, h interface{}, opts ...SubscriberOption) Subscriber
+	// Register a subscriber
+	Subscribe(s Subscriber) error
 	// Start the server
 	Start() error
 	// Stop the server
@@ -56,6 +60,30 @@ type Server interface {
 	String() string
 }
 
+/*
+// Router handle serving messages
+type Router interface {
+	// ProcessMessage processes a message
+	ProcessMessage(ctx context.Context, msg Message) error
+	// ServeRequest processes a request to completion
+	ServeRequest(ctx context.Context, req Request, rsp Response) error
+}
+*/
+
+// Message is an async message interface
+type Message interface {
+	// Topic of the message
+	Topic() string
+	// The decoded payload value
+	Body() interface{}
+	// The content type of the payload
+	ContentType() string
+	// The raw headers of the message
+	Header() metadata.Metadata
+	// Codec used to decode the message
+	Codec() codec.Codec
+}
+
 // Request is a synchronous request interface
 type Request interface {
 	// Service name requested
@@ -117,14 +145,25 @@ 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{}
 	Endpoints() []*register.Endpoint
 	Options() HandlerOptions
 }
+
+// Subscriber interface represents a subscription to a given topic using
+// a specific subscriber function or object with endpoints. It mirrors
+// the handler in its behaviour.
+type Subscriber interface {
+	Topic() string
+	Subscriber() interface{}
+	Endpoints() []*register.Endpoint
+	Options() SubscriberOptions
+}

server/subscriber.go

@@ -0,0 +1,437 @@
+package server
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"reflect"
+	"runtime/debug"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"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 (
+	subSig      = "func(context.Context, interface{}) error"
+	batchSubSig = "func([]context.Context, []interface{}) error"
+)
+
+// Precompute the reflect type for error. Can't use error directly
+// because Typeof takes an empty interface value. This is annoying.
+var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
+
+type handler struct {
+	reqType reflect.Type
+	ctxType reflect.Type
+	method  reflect.Value
+}
+
+type subscriber struct {
+	typ        reflect.Type
+	subscriber interface{}
+	topic      string
+	endpoints  []*register.Endpoint
+	handlers   []*handler
+	opts       SubscriberOptions
+	rcvr       reflect.Value
+}
+
+// Is this an exported - upper case - name?
+func isExported(name string) bool {
+	rune, _ := utf8.DecodeRuneInString(name)
+	return unicode.IsUpper(rune)
+}
+
+// Is this type exported or a builtin?
+func isExportedOrBuiltinType(t reflect.Type) bool {
+	for t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	// PkgPath will be non-empty even for an exported type,
+	// so we need to check the type name as well.
+	return isExported(t.Name()) || t.PkgPath() == ""
+}
+
+// ValidateSubscriber func signature
+func ValidateSubscriber(sub Subscriber) error {
+	typ := reflect.TypeOf(sub.Subscriber())
+	var argType reflect.Type
+	switch typ.Kind() {
+	case reflect.Func:
+		name := "Func"
+		switch typ.NumIn() {
+		case 2:
+			argType = typ.In(1)
+			if sub.Options().Batch {
+				if argType.Kind() != reflect.Slice {
+					return fmt.Errorf("subscriber %v dont have required signature %s", name, batchSubSig)
+				}
+				if strings.Compare(fmt.Sprintf("%v", argType), "[]interface{}") == 0 {
+					return fmt.Errorf("subscriber %v dont have required signaure %s", name, batchSubSig)
+				}
+			}
+		default:
+			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s or %s", name, typ.NumIn(), subSig, batchSubSig)
+		}
+		if !isExportedOrBuiltinType(argType) {
+			return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
+		}
+		if typ.NumOut() != 1 {
+			return fmt.Errorf("subscriber %v has wrong number of return values: %v require signature %s or %s",
+				name, typ.NumOut(), subSig, batchSubSig)
+		}
+		if returnType := typ.Out(0); returnType != typeOfError {
+			return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
+		}
+	default:
+		hdlr := reflect.ValueOf(sub.Subscriber())
+		name := reflect.Indirect(hdlr).Type().Name()
+
+		for m := 0; m < typ.NumMethod(); m++ {
+			method := typ.Method(m)
+			switch method.Type.NumIn() {
+			case 3:
+				argType = method.Type.In(2)
+			default:
+				return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s or %s",
+					name, method.Name, method.Type.NumIn(), subSig, batchSubSig)
+			}
+
+			if !isExportedOrBuiltinType(argType) {
+				return fmt.Errorf("%v argument type not exported: %v", name, argType)
+			}
+			if method.Type.NumOut() != 1 {
+				return fmt.Errorf(
+					"subscriber %v.%v has wrong number of return values: %v require signature %s or %s",
+					name, method.Name, method.Type.NumOut(), subSig, batchSubSig)
+			}
+			if returnType := method.Type.Out(0); returnType != typeOfError {
+				return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
+			}
+		}
+	}
+
+	return nil
+}
+
+func newSubscriber(topic string, sub interface{}, opts ...SubscriberOption) Subscriber {
+	var endpoints []*register.Endpoint
+	var handlers []*handler
+
+	options := NewSubscriberOptions(opts...)
+
+	if typ := reflect.TypeOf(sub); typ.Kind() == reflect.Func {
+		h := &handler{
+			method: reflect.ValueOf(sub),
+		}
+
+		switch typ.NumIn() {
+		case 1:
+			h.reqType = typ.In(0)
+		case 2:
+			h.ctxType = typ.In(0)
+			h.reqType = typ.In(1)
+		}
+
+		handlers = append(handlers, h)
+		ep := &register.Endpoint{
+			Name:     "Func",
+			Request:  register.ExtractSubValue(typ),
+			Metadata: metadata.New(2),
+		}
+		ep.Metadata.Set("topic", topic)
+		ep.Metadata.Set("subscriber", "true")
+		endpoints = append(endpoints, ep)
+	} else {
+		hdlr := reflect.ValueOf(sub)
+		name := reflect.Indirect(hdlr).Type().Name()
+
+		for m := 0; m < typ.NumMethod(); m++ {
+			method := typ.Method(m)
+			h := &handler{
+				method: method.Func,
+			}
+
+			switch method.Type.NumIn() {
+			case 2:
+				h.reqType = method.Type.In(1)
+			case 3:
+				h.ctxType = method.Type.In(1)
+				h.reqType = method.Type.In(2)
+			}
+
+			handlers = append(handlers, h)
+			ep := &register.Endpoint{
+				Name:     name + "." + method.Name,
+				Request:  register.ExtractSubValue(method.Type),
+				Metadata: metadata.New(2),
+			}
+			ep.Metadata.Set("topic", topic)
+			ep.Metadata.Set("subscriber", "true")
+			endpoints = append(endpoints, ep)
+		}
+	}
+
+	return &subscriber{
+		rcvr:       reflect.ValueOf(sub),
+		typ:        reflect.TypeOf(sub),
+		topic:      topic,
+		subscriber: sub,
+		handlers:   handlers,
+		endpoints:  endpoints,
+		opts:       options,
+	}
+}
+
+//nolint:gocyclo
+func (n *noopServer) createBatchSubHandler(sb *subscriber, opts Options) broker.BatchHandler {
+	return func(ps broker.Events) (err error) {
+		defer func() {
+			if r := recover(); r != nil {
+				n.RLock()
+				config := n.opts
+				n.RUnlock()
+				if config.Logger.V(logger.ErrorLevel) {
+					config.Logger.Error(n.opts.Context, "panic recovered: ", r)
+					config.Logger.Error(n.opts.Context, string(debug.Stack()))
+				}
+				err = errors.InternalServerError(n.opts.Name+".subscriber", "panic recovered: %v", r)
+			}
+		}()
+
+		msgs := make([]Message, 0, len(ps))
+		ctxs := make([]context.Context, 0, len(ps))
+		for _, p := range ps {
+			msg := p.Message()
+			// if we don't have headers, create empty map
+			if msg.Header == nil {
+				msg.Header = metadata.New(2)
+			}
+
+			ct, _ := msg.Header.Get(metadata.HeaderContentType)
+			if len(ct) == 0 {
+				msg.Header.Set(metadata.HeaderContentType, defaultContentType)
+				ct = defaultContentType
+			}
+			hdr := metadata.Copy(msg.Header)
+			topic, _ := msg.Header.Get(metadata.HeaderTopic)
+			ctxs = append(ctxs, metadata.NewIncomingContext(sb.opts.Context, hdr))
+			msgs = append(msgs, &rpcMessage{
+				topic:       topic,
+				contentType: ct,
+				header:      msg.Header,
+				body:        msg.Body,
+			})
+		}
+		results := make(chan error, len(sb.handlers))
+
+		for i := 0; i < len(sb.handlers); i++ {
+			handler := sb.handlers[i]
+
+			var req reflect.Value
+
+			switch handler.reqType.Kind() {
+			case reflect.Ptr:
+				req = reflect.New(handler.reqType.Elem())
+			default:
+				req = reflect.New(handler.reqType.Elem()).Elem()
+			}
+
+			reqType := handler.reqType
+			var cf codec.Codec
+			for _, msg := range msgs {
+				cf, err = n.newCodec(msg.ContentType())
+				if err != nil {
+					return err
+				}
+				rb := reflect.New(req.Type().Elem())
+				if err = cf.ReadBody(bytes.NewReader(msg.(*rpcMessage).body), rb.Interface()); err != nil {
+					return err
+				}
+				msg.(*rpcMessage).codec = cf
+				msg.(*rpcMessage).payload = rb.Interface()
+			}
+
+			fn := func(ctxs []context.Context, ms []Message) error {
+				var vals []reflect.Value
+				if sb.typ.Kind() != reflect.Func {
+					vals = append(vals, sb.rcvr)
+				}
+				if handler.ctxType != nil {
+					vals = append(vals, reflect.ValueOf(ctxs))
+				}
+				payloads := reflect.MakeSlice(reqType, 0, len(ms))
+				for _, m := range ms {
+					payloads = reflect.Append(payloads, reflect.ValueOf(m.Body()))
+				}
+				vals = append(vals, payloads)
+
+				returnValues := handler.method.Call(vals)
+				if rerr := returnValues[0].Interface(); rerr != nil {
+					return rerr.(error)
+				}
+				return nil
+			}
+
+			for i := len(opts.BatchSubWrappers); i > 0; i-- {
+				fn = opts.BatchSubWrappers[i-1](fn)
+			}
+
+			if n.wg != nil {
+				n.wg.Add(1)
+			}
+			go func() {
+				if n.wg != nil {
+					defer n.wg.Done()
+				}
+				results <- fn(ctxs, msgs)
+			}()
+		}
+
+		var errors []string
+		for i := 0; i < len(sb.handlers); i++ {
+			if rerr := <-results; rerr != nil {
+				errors = append(errors, rerr.Error())
+			}
+		}
+		if len(errors) > 0 {
+			err = fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n"))
+		}
+		return err
+	}
+}
+
+//nolint:gocyclo
+func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handler {
+	return func(p broker.Event) (err error) {
+		defer func() {
+			if r := recover(); r != nil {
+				n.RLock()
+				config := n.opts
+				n.RUnlock()
+				if config.Logger.V(logger.ErrorLevel) {
+					config.Logger.Error(n.opts.Context, "panic recovered: ", r)
+					config.Logger.Error(n.opts.Context, string(debug.Stack()))
+				}
+				err = errors.InternalServerError(n.opts.Name+".subscriber", "panic recovered: %v", r)
+			}
+		}()
+
+		msg := p.Message()
+		// if we don't have headers, create empty map
+		if msg.Header == nil {
+			msg.Header = metadata.New(2)
+		}
+
+		ct := msg.Header["Content-Type"]
+		if len(ct) == 0 {
+			msg.Header.Set(metadata.HeaderContentType, defaultContentType)
+			ct = defaultContentType
+		}
+		cf, err := n.newCodec(ct)
+		if err != nil {
+			return err
+		}
+
+		hdr := metadata.New(len(msg.Header))
+		for k, v := range msg.Header {
+			hdr.Set(k, v)
+		}
+
+		ctx := metadata.NewIncomingContext(sb.opts.Context, hdr)
+
+		results := make(chan error, len(sb.handlers))
+
+		for i := 0; i < len(sb.handlers); i++ {
+			handler := sb.handlers[i]
+
+			var isVal bool
+			var req reflect.Value
+
+			if handler.reqType.Kind() == reflect.Ptr {
+				req = reflect.New(handler.reqType.Elem())
+			} else {
+				req = reflect.New(handler.reqType)
+				isVal = true
+			}
+			if isVal {
+				req = req.Elem()
+			}
+
+			if err = cf.ReadBody(bytes.NewBuffer(msg.Body), req.Interface()); err != nil {
+				return err
+			}
+
+			fn := func(ctx context.Context, msg Message) error {
+				var vals []reflect.Value
+				if sb.typ.Kind() != reflect.Func {
+					vals = append(vals, sb.rcvr)
+				}
+				if handler.ctxType != nil {
+					vals = append(vals, reflect.ValueOf(ctx))
+				}
+
+				vals = append(vals, reflect.ValueOf(msg.Body()))
+
+				returnValues := handler.method.Call(vals)
+				if rerr := returnValues[0].Interface(); rerr != nil {
+					return rerr.(error)
+				}
+				return nil
+			}
+
+			for i := len(opts.SubWrappers); i > 0; i-- {
+				fn = opts.SubWrappers[i-1](fn)
+			}
+
+			if n.wg != nil {
+				n.wg.Add(1)
+			}
+			go func() {
+				if n.wg != nil {
+					defer n.wg.Done()
+				}
+				cerr := fn(ctx, &rpcMessage{
+					topic:       sb.topic,
+					contentType: ct,
+					payload:     req.Interface(),
+					header:      msg.Header,
+				})
+				results <- cerr
+			}()
+		}
+		var errors []string
+		for i := 0; i < len(sb.handlers); i++ {
+			if rerr := <-results; rerr != nil {
+				errors = append(errors, rerr.Error())
+			}
+		}
+		if len(errors) > 0 {
+			err = fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n"))
+		}
+		return err
+	}
+}
+
+func (s *subscriber) Topic() string {
+	return s.topic
+}
+
+func (s *subscriber) Subscriber() interface{} {
+	return s.subscriber
+}
+
+func (s *subscriber) Endpoints() []*register.Endpoint {
+	return s.endpoints
+}
+
+func (s *subscriber) Options() SubscriberOptions {
+	return s.opts
+}

server/wrapper.go

@@ -9,9 +9,25 @@ import (
 // request and response types.
 type HandlerFunc func(ctx context.Context, req Request, rsp interface{}) error
 
+// SubscriberFunc represents a single method of a subscriber. It's used primarily
+// for the wrappers. What's handed to the actual method is the concrete
+// publication message.
+type SubscriberFunc func(ctx context.Context, msg Message) error
+
+// BatchSubscriberFunc represents a single method of a subscriber. It's used primarily
+// for the wrappers. What's handed to the actual method is the concrete
+// publication message. This func used by batch subscribers
+type BatchSubscriberFunc func(ctxs []context.Context, msgs []Message) error
+
 // HandlerWrapper wraps the HandlerFunc and returns the equivalent
 type HandlerWrapper func(HandlerFunc) HandlerFunc
 
+// SubscriberWrapper wraps the SubscriberFunc and returns the equivalent
+type SubscriberWrapper func(SubscriberFunc) SubscriberFunc
+
+// BatchSubscriberWrapper wraps the SubscriberFunc and returns the equivalent
+type BatchSubscriberWrapper func(BatchSubscriberFunc) BatchSubscriberFunc
+
 // StreamWrapper wraps a Stream interface and returns the equivalent.
 // Because streams exist for the lifetime of a method invocation this
 // is a convenient way to wrap a Stream as its in use for trace, monitoring,

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.
@@ -66,6 +66,11 @@ func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOptio
 	return s.Handle(s.NewHandler(h, opts...))
 }
 
+// RegisterSubscriber is syntactic sugar for registering a subscriber
+func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error {
+	return s.Subscribe(s.NewSubscriber(topic, h, opts...))
+}
+
 type service struct {
 	sync.RWMutex
 	opts Options
@@ -371,19 +376,71 @@ func (s *service) Run() error {
 	return s.Stop()
 }
 
-type nameIface interface {
-	Name() string
-}
-
 func getNameIndex(n string, ifaces interface{}) int {
-	values, ok := ifaces.([]interface{})
-	if !ok {
-		return 0
-	}
-	for idx, iface := range values {
-		if ifc, ok := iface.(nameIface); ok && ifc.Name() == n {
-			return idx
+	switch values := ifaces.(type) {
+	case []router.Router:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
 		}
+	case []register.Register:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []store.Store:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []tracer.Tracer:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []server.Server:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []config.Config:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []meter.Meter:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []broker.Broker:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+	case []client.Client:
+		for idx, iface := range values {
+			if iface.Name() == n {
+				return idx
+			}
+		}
+		/*
+			case []logger.Logger:
+					for idx, iface := range values {
+						if iface.Name() == n {
+							return idx
+						}
+					}
+		*/
 	}
+
 	return 0
 }

service_test.go

@@ -1,21 +1,37 @@
 package micro
 
 import (
+	"context"
 	"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"
 )
 
+func TestClient(t *testing.T) {
+	c1 := client.NewClient(client.Name("test1"))
+	c2 := client.NewClient(client.Name("test2"))
+
+	svc := NewService(Client(c1, c2))
+	if err := svc.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	x1 := svc.Client("test2")
+	if x1.Name() != "test2" {
+		t.Fatal("invalid client")
+	}
+}
+
 type testItem struct {
 	name string
 }
@@ -64,6 +80,41 @@ func TestRegisterHandler(t *testing.T) {
 	}
 }
 
+func TestRegisterSubscriber(t *testing.T) {
+	type args struct {
+		topic string
+		s     server.Server
+		h     interface{}
+		opts  []server.SubscriberOption
+	}
+	h := func(_ context.Context, _ interface{}) error {
+		return nil
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "RegisterSubscriber",
+			args: args{
+				topic: "test",
+				s:     server.DefaultServer,
+				h:     h,
+				opts:  nil,
+			},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := RegisterSubscriber(tt.args.topic, tt.args.s, tt.args.h, tt.args.opts...); (err != nil) != tt.wantErr {
+				t.Errorf("RegisterSubscriber() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
 func TestNewService(t *testing.T) {
 	type args struct {
 		opts []Option
@@ -186,6 +237,7 @@ func Test_service_Options(t *testing.T) {
 }
 
 func Test_service_Broker(t *testing.T) {
+	b := broker.NewBroker()
 	type fields struct {
 		opts Options
 	}
@@ -201,12 +253,12 @@ func Test_service_Broker(t *testing.T) {
 		{
 			name: "service.Broker",
 			fields: fields{
-				opts: Options{Brokers: []broker.Broker{broker.DefaultBroker}},
+				opts: Options{Brokers: []broker.Broker{b}},
 			},
 			args: args{
 				names: []string{"noop"},
 			},
-			want: broker.DefaultBroker,
+			want: b,
 		},
 	}
 	for _, tt := range tests {

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) {