config/default: watcher send changes only on non nil

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

.github/dependabot.yml

@@ -0,0 +1,19 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+
+  # Maintain dependencies for Golang
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/generate.sh

@@ -1,15 +0,0 @@
-#!/bin/bash -e
-
-find . -type f -name '*.pb.*.go' -o -name '*.pb.go' -a ! -name 'message.pb.go' -delete
-PROTOS=$(find . -type f -name '*.proto' | grep -v proto/google/api)
-
-mkdir -p proto/google/api
-curl -s -o proto/google/api/annotations.proto -L https://raw.githubusercontent.com/googleapis/googleapis/master/google/api/annotations.proto
-curl -s -o proto/google/api/http.proto -L https://raw.githubusercontent.com/googleapis/googleapis/master/google/api/http.proto
-
-for PROTO in $PROTOS; do
-  echo $PROTO
-  protoc -I./proto -I. -I$(dirname $PROTO) --go-grpc_out=paths=source_relative:. --go_out=paths=source_relative:. --micro_out=paths=source_relative:. $PROTO
-done
-
-rm -r proto

.github/renovate.json

@@ -1,20 +0,0 @@
-{
-  "extends": [
-    "config:base"
-  ],
-  "postUpdateOptions": ["gomodTidy"],
-  "packageRules": [
-    {
-      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
-      "automerge": true
-    },
-    {
-      "groupName": "all deps",
-      "separateMajorMinor": true,
-      "groupSlug": "all",
-      "packagePatterns": [
-        "*"
-      ]
-    }
-  ]
-}

.github/stale.sh

@@ -1,13 +0,0 @@
-#!/bin/bash -ex
-
-export PATH=$PATH:$(pwd)/bin
-export GO111MODULE=on
-export GOBIN=$(pwd)/bin
-
-#go get github.com/rvflash/goup@v0.4.1
-
-#goup -v ./...
-#go get github.com/psampaz/go-mod-outdated@v0.6.0
-go list -u -m -mod=mod -json all | go-mod-outdated -update -direct -ci || true
-
-#go list -u -m -json all | go-mod-outdated -update

.github/workflows/build.yml

@@ -53,7 +53,7 @@ jobs:
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.30
+          version: v1.39
           # Optional: working directory, useful for monorepos
           # working-directory: somedir
           # Optional: golangci-lint command line arguments.

.github/workflows/pr.yml

@@ -53,7 +53,7 @@ jobs:
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.30
+          version: v1.39
           # Optional: working directory, useful for monorepos
           # working-directory: somedir
           # Optional: golangci-lint command line arguments.

.golangci.yml

@@ -1,30 +1,44 @@
 run:
+  concurrency: 4
   deadline: 5m
-  modules-download-mode: readonly
-  skip-files:
-    - ".*\\.pb\\.go$"
-    - ".*\\.pb\\.micro\\.go$"
+  issues-exit-code: 1
+  tests: true
+
+linters-settings:
+  govet:
+    check-shadowing: true
+    enable:
+      - fieldalignment
+
 linters:
-  disable-all: false
-  enable-all: false
   enable:
-    - megacheck
-    - staticcheck
-    - deadcode
-    - varcheck
-    - gosimple
-    - unused
-    - prealloc
-    - scopelint
-    - gocritic
-    - goimports
-    - unconvert
     - govet
-    - nakedret
+    - deadcode
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
     - structcheck
-    - gosec
-  disable:
-    - maligned
-    - interfacer
     - typecheck
-    - dupl
+    - unused
+    - varcheck
+    - bodyclose
+    - gci
+    - goconst
+    - gocritic
+    - gosimple
+    - gofmt
+    - gofumpt
+    - goimports
+    - golint
+    - gosec
+    - makezero
+    - misspell
+    - nakedret
+    - nestif
+    - nilerr
+    - noctx
+    - prealloc
+    - unconvert
+    - unparam
+  disable-all: false

api/api_test.go

@@ -149,5 +149,4 @@ func TestValidate(t *testing.T) {
 	if err := Validate(epPcreInvalid); err == nil {
 		t.Fatalf("invalid pcre %v", epPcreInvalid.Path[0])
 	}
-
 }

api/handler/options.go

@@ -6,10 +6,8 @@ import (
 	"github.com/unistack-org/micro/v3/logger"
 )
 
-var (
-	// DefaultMaxRecvSize specifies max recv size for handler
-	DefaultMaxRecvSize int64 = 1024 * 1024 * 100 // 10Mb
-)
+// DefaultMaxRecvSize specifies max recv size for handler
+var DefaultMaxRecvSize int64 = 1024 * 1024 * 100 // 10Mb
 
 // Options struct holds handler options
 type Options struct {

api/resolver/subdomain/subdomain.go

@@ -15,12 +15,12 @@ import (
 // NewResolver creates new subdomain api resolver
 func NewResolver(parent resolver.Resolver, opts ...resolver.Option) resolver.Resolver {
 	options := resolver.NewOptions(opts...)
-	return &subdomainResolver{options, parent}
+	return &subdomainResolver{opts: options, Resolver: parent}
 }
 
 type subdomainResolver struct {
-	opts resolver.Options
 	resolver.Resolver
+	opts resolver.Options
 }
 
 // Resolve resolve endpoint based on subdomain

api/resolver/vpath/vpath.go

@@ -19,9 +19,7 @@ type vpathResolver struct {
 	opts resolver.Options
 }
 
-var (
-	re = regexp.MustCompile("^v[0-9]+$")
-)
+var re = regexp.MustCompile("^v[0-9]+$")
 
 // Resolve endpoint
 func (r *vpathResolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {

api/router/router.go

@@ -7,10 +7,8 @@ import (
 	"github.com/unistack-org/micro/v3/api"
 )
 
-var (
-	// DefaultRouter contains default router implementation
-	DefaultRouter Router
-)
+// DefaultRouter contains default router implementation
+var DefaultRouter Router
 
 // Router is used to determine an endpoint for a request
 type Router interface {

auth/rules_test.go

@@ -24,11 +24,11 @@ func TestVerify(t *testing.T) {
 	}
 
 	tt := []struct {
-		Name     string
-		Rules    []*Rule
+		Error    error
 		Account  *Account
 		Resource *Resource
-		Error    error
+		Name     string
+		Rules    []*Rule
 	}{
 		{
 			Name:     "NoRules",

broker/broker.go

@@ -3,48 +3,128 @@ package broker
 
 import (
 	"context"
+	"errors"
 
 	"github.com/unistack-org/micro/v3/metadata"
 )
 
+// DefaultBroker default memory broker
+var DefaultBroker Broker = NewBroker()
+
 var (
-	// DefaultBroker default broker
-	DefaultBroker Broker = NewBroker()
+	// 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")
 )
 
 // Broker is an interface used for asynchronous messaging.
 type Broker interface {
+	// Name returns broker instance name
 	Name() string
-	Init(...Option) error
+	// Init initilize broker
+	Init(opts ...Option) error
+	// Options returns broker options
 	Options() Options
+	// Address return configured address
 	Address() string
-	Connect(context.Context) error
-	Disconnect(context.Context) error
-	Publish(context.Context, string, *Message, ...PublishOption) error
-	Subscribe(context.Context, string, Handler, ...SubscribeOption) (Subscriber, error)
+	// Connect connects to broker
+	Connect(ctx context.Context) error
+	// Disconnect disconnect from broker
+	Disconnect(ctx context.Context) error
+	// Publish message to broker topic
+	Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	// Subscribe subscribes to topic message via handler
+	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
 }
 
 // Handler is used to process messages via a subscription of a topic.
 type Handler func(Event) error
 
+// Events contains multiple events
+type Events []Event
+
+func (evs Events) Ack() error {
+	var err error
+	for _, ev := range evs {
+		if err = ev.Ack(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+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
+	// Message returns broker message
 	Message() *Message
+	// Ack acknowledge message
 	Ack() error
+	// Error returns message error (like decoding errors or some other)
 	Error() error
+	// SetError set event processing error
+	SetError(err error)
+}
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
 }
 
 // Message is used to transfer data
 type Message struct {
-	Header metadata.Metadata // contains message metadata
-	Body   []byte            // contains message body
+	// Header contains message metadata
+	Header metadata.Metadata
+	// Body contains message body
+	Body RawMessage
+}
+
+// NewMessage create broker message with topic filled
+func NewMessage(topic string) *Message {
+	m := &Message{Header: metadata.New(2)}
+	m.Header.Set(metadata.HeaderTopic, topic)
+	return m
 }
 
 // Subscriber is a convenience return type for the Subscribe method
 type Subscriber interface {
+	// Options returns subscriber options
 	Options() SubscribeOptions
+	// Topic returns topic for subscription
 	Topic() string
-	Unsubscribe(context.Context) error
+	// Unsubscribe from topic
+	Unsubscribe(ctx context.Context) error
 }

broker/memory.go

@@ -2,38 +2,39 @@ package broker
 
 import (
 	"context"
-	"errors"
 	"sync"
 
 	"github.com/google/uuid"
 	"github.com/unistack-org/micro/v3/logger"
+	"github.com/unistack-org/micro/v3/metadata"
 	maddr "github.com/unistack-org/micro/v3/util/addr"
 	mnet "github.com/unistack-org/micro/v3/util/net"
 	"github.com/unistack-org/micro/v3/util/rand"
 )
 
 type memoryBroker struct {
-	opts        Options
-	Subscribers map[string][]*memorySubscriber
+	subscribers map[string][]*memorySubscriber
 	addr        string
+	opts        Options
 	sync.RWMutex
 	connected bool
 }
 
 type memoryEvent struct {
-	opts    Options
 	err     error
 	message interface{}
 	topic   string
+	opts    Options
 }
 
 type memorySubscriber struct {
-	opts    SubscribeOptions
-	ctx     context.Context
-	exit    chan bool
-	handler Handler
-	id      string
-	topic   string
+	ctx          context.Context
+	exit         chan bool
+	handler      Handler
+	batchhandler BatchHandler
+	id           string
+	topic        string
+	opts         SubscribeOptions
 }
 
 func (m *memoryBroker) Options() Options {
@@ -77,7 +78,6 @@ func (m *memoryBroker) Disconnect(ctx context.Context) error {
 	}
 
 	m.connected = false
-
 	return nil
 }
 
@@ -92,67 +92,190 @@ func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *Message,
 	m.RLock()
 	if !m.connected {
 		m.RUnlock()
-		return errors.New("not connected")
+		return ErrNotConnected
 	}
-
-	subs, ok := m.Subscribers[topic]
 	m.RUnlock()
-	if !ok {
-		return nil
-	}
 
-	var v interface{}
-	if m.opts.Codec != nil {
+	options := NewPublishOptions(opts...)
+	vs := make([]msgWrapper, 0, 1)
+	if m.opts.Codec == nil || options.BodyOnly {
+		topic, _ := msg.Header.Get(metadata.HeaderTopic)
+		vs = append(vs, msgWrapper{topic: topic, body: msg})
+	} else {
+		topic, _ := msg.Header.Get(metadata.HeaderTopic)
 		buf, err := m.opts.Codec.Marshal(msg)
 		if err != nil {
 			return err
 		}
-		v = buf
+		vs = append(vs, msgWrapper{topic: topic, body: buf})
+	}
+
+	return m.publish(ctx, vs, opts...)
+}
+
+type msgWrapper struct {
+	topic string
+	body  interface{}
+}
+
+func (m *memoryBroker) BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
+	m.RLock()
+	if !m.connected {
+		m.RUnlock()
+		return ErrNotConnected
+	}
+	m.RUnlock()
+
+	options := NewPublishOptions(opts...)
+	vs := make([]msgWrapper, 0, len(msgs))
+	if m.opts.Codec == nil || options.BodyOnly {
+		for _, msg := range msgs {
+			topic, _ := msg.Header.Get(metadata.HeaderTopic)
+			vs = append(vs, msgWrapper{topic: topic, body: msg})
+		}
 	} else {
-		v = msg
+		for _, msg := range msgs {
+			topic, _ := msg.Header.Get(metadata.HeaderTopic)
+			buf, err := m.opts.Codec.Marshal(msg)
+			if err != nil {
+				return err
+			}
+			vs = append(vs, msgWrapper{topic: topic, body: buf})
+		}
 	}
 
-	p := &memoryEvent{
-		topic:   topic,
-		message: v,
-		opts:    m.opts,
+	return m.publish(ctx, vs, opts...)
+}
+
+func (m *memoryBroker) publish(ctx context.Context, vs []msgWrapper, opts ...PublishOption) error {
+	var err error
+
+	msgTopicMap := make(map[string]Events)
+	for _, v := range vs {
+		p := &memoryEvent{
+			topic:   v.topic,
+			message: v.body,
+			opts:    m.opts,
+		}
+		msgTopicMap[p.topic] = append(msgTopicMap[p.topic], p)
 	}
 
+	beh := m.opts.BatchErrorHandler
 	eh := m.opts.ErrorHandler
 
-	for _, sub := range subs {
-		if err := sub.handler(p); err != nil {
-			p.err = err
-			if sub.opts.ErrorHandler != nil {
-				eh = sub.opts.ErrorHandler
-			}
-			if eh != nil {
-				eh(p)
-			} else if m.opts.Logger.V(logger.ErrorLevel) {
-				m.opts.Logger.Error(m.opts.Context, err.Error())
-			}
+	for t, ms := range msgTopicMap {
+		m.RLock()
+		subs, ok := m.subscribers[t]
+		m.RUnlock()
+		if !ok {
 			continue
 		}
+
+		for _, sub := range subs {
+			// batch processing
+			if sub.batchhandler != nil {
+				if err = sub.batchhandler(ms); err != nil {
+					ms.SetError(err)
+					if sub.opts.BatchErrorHandler != nil {
+						beh = sub.opts.BatchErrorHandler
+					}
+					if beh != nil {
+						beh(ms)
+					} else if m.opts.Logger.V(logger.ErrorLevel) {
+						m.opts.Logger.Error(m.opts.Context, err.Error())
+					}
+				} else if sub.opts.AutoAck {
+					if err = ms.Ack(); err != nil {
+						m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
+					}
+				}
+			}
+			// single processing
+			if sub.handler != nil {
+				for _, p := range ms {
+					if err = sub.handler(p); err != nil {
+						p.SetError(err)
+						if sub.opts.ErrorHandler != nil {
+							eh = sub.opts.ErrorHandler
+						}
+						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)
+						}
+					}
+				}
+			}
+		}
 	}
 
 	return nil
 }
 
-func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler Handler, 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, errors.New("not connected")
+		return nil, ErrNotConnected
 	}
 	m.RUnlock()
 
-	options := NewSubscribeOptions(opts...)
-
 	id, err := uuid.NewRandom()
 	if err != nil {
 		return nil, err
 	}
 
+	options := NewSubscribeOptions(opts...)
+
+	sub := &memorySubscriber{
+		exit:         make(chan bool, 1),
+		id:           id.String(),
+		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()
+		return nil, ErrNotConnected
+	}
+	m.RUnlock()
+
+	id, err := uuid.NewRandom()
+	if err != nil {
+		return nil, err
+	}
+
+	options := NewSubscribeOptions(opts...)
+
 	sub := &memorySubscriber{
 		exit:    make(chan bool, 1),
 		id:      id.String(),
@@ -163,20 +286,20 @@ func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler Hand
 	}
 
 	m.Lock()
-	m.Subscribers[topic] = append(m.Subscribers[topic], sub)
+	m.subscribers[topic] = append(m.subscribers[topic], sub)
 	m.Unlock()
 
 	go func() {
 		<-sub.exit
 		m.Lock()
-		var newSubscribers []*memorySubscriber
-		for _, sb := range m.Subscribers[topic] {
+		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.subscribers[topic] = newSubscribers
 		m.Unlock()
 	}()
 
@@ -221,6 +344,10 @@ func (m *memoryEvent) Error() error {
 	return m.err
 }
 
+func (m *memoryEvent) SetError(err error) {
+	m.err = err
+}
+
 func (m *memorySubscriber) Options() SubscribeOptions {
 	return m.opts
 }
@@ -238,6 +365,6 @@ func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
 func NewBroker(opts ...Option) Broker {
 	return &memoryBroker{
 		opts:        NewOptions(opts...),
-		Subscribers: make(map[string][]*memorySubscriber),
+		subscribers: make(map[string][]*memorySubscriber),
 	}
 }

broker/memory_test.go

@@ -4,8 +4,55 @@ import (
 	"context"
 	"fmt"
 	"testing"
+
+	"github.com/unistack-org/micro/v3/metadata"
 )
 
+func TestMemoryBatchBroker(t *testing.T) {
+	b := NewBroker()
+	ctx := context.Background()
+
+	if err := b.Connect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+
+	topic := "test"
+	count := 10
+
+	fn := func(evts Events) error {
+		return evts.Ack()
+	}
+
+	sub, err := b.BatchSubscribe(ctx, topic, fn)
+	if err != nil {
+		t.Fatalf("Unexpected error subscribing %v", err)
+	}
+
+	msgs := make([]*Message, 0, 0)
+	for i := 0; i < count; i++ {
+		message := &Message{
+			Header: map[string]string{
+				metadata.HeaderTopic: topic,
+				"foo":                "bar",
+				"id":                 fmt.Sprintf("%d", i),
+			},
+			Body: []byte(`"hello world"`),
+		}
+		msgs = append(msgs, message)
+	}
+
+	if err := b.BatchPublish(ctx, msgs); err != nil {
+		t.Fatalf("Unexpected error publishing %v", err)
+	}
+
+	if err := sub.Unsubscribe(ctx); err != nil {
+		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
+	}
+
+	if err := b.Disconnect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+}
 func TestMemoryBroker(t *testing.T) {
 	b := NewBroker()
 	ctx := context.Background()
@@ -26,20 +73,27 @@ func TestMemoryBroker(t *testing.T) {
 		t.Fatalf("Unexpected error subscribing %v", err)
 	}
 
+	msgs := make([]*Message, 0, 0)
 	for i := 0; i < count; i++ {
 		message := &Message{
 			Header: map[string]string{
-				"foo": "bar",
-				"id":  fmt.Sprintf("%d", i),
+				metadata.HeaderTopic: topic,
+				"foo":                "bar",
+				"id":                 fmt.Sprintf("%d", i),
 			},
-			Body: []byte(`hello world`),
+			Body: []byte(`"hello world"`),
 		}
+		msgs = append(msgs, message)
 
 		if err := b.Publish(ctx, topic, message); err != nil {
-			t.Fatalf("Unexpected error publishing %d", i)
+			t.Fatalf("Unexpected error publishing %d err: %v", i, err)
 		}
 	}
 
+	if err := b.BatchPublish(ctx, msgs); err != nil {
+		t.Fatalf("Unexpected error publishing %v", err)
+	}
+
 	if err := sub.Unsubscribe(ctx); err != nil {
 		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
 	}

broker/options.go

@@ -3,6 +3,7 @@ package broker
 import (
 	"context"
 	"crypto/tls"
+	"time"
 
 	"github.com/unistack-org/micro/v3/codec"
 	"github.com/unistack-org/micro/v3/logger"
@@ -29,6 +30,8 @@ type Options struct {
 	TLSConfig *tls.Config
 	// ErrorHandler used when broker can't unmarshal incoming 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
@@ -71,11 +74,9 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 	options := PublishOptions{
 		Context: context.Background(),
 	}
-
 	for _, o := range opts {
 		o(&options)
 	}
-
 	return options
 }
 
@@ -85,12 +86,18 @@ type SubscribeOptions struct {
 	Context context.Context
 	// ErrorHandler used when broker can't unmarshal incoming message
 	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
 	BodyOnly bool
+	// BatchSize flag specifies max batch size
+	BatchSize int
+	// BatchWait flag specifies max wait time for batch filling
+	BatchWait time.Duration
 }
 
 // Option func
@@ -113,23 +120,6 @@ func PublishContext(ctx context.Context) PublishOption {
 	}
 }
 
-// SubscribeOption func
-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
-}
-
 // Addrs sets the host addresses to be used by the broker
 func Addrs(addrs ...string) Option {
 	return func(o *Options) {
@@ -145,28 +135,6 @@ func Codec(c codec.Codec) Option {
 	}
 }
 
-// DisableAutoAck disables auto ack
-func DisableAutoAck() SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = false
-	}
-}
-
-// SubscribeAutoAck will disable auto acking of messages
-// after they have been handled.
-func SubscribeAutoAck(b bool) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = b
-	}
-}
-
-// SubscribeBodyOnly consumes only body of the message
-func SubscribeBodyOnly(b bool) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.BodyOnly = b
-	}
-}
-
 // ErrorHandler will catch all broker errors that cant be handled
 // in normal way, for example Codec errors
 func ErrorHandler(h Handler) Option {
@@ -175,6 +143,14 @@ func ErrorHandler(h Handler) Option {
 	}
 }
 
+// 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 Handler) SubscribeOption {
@@ -183,6 +159,14 @@ func SubscribeErrorHandler(h Handler) SubscribeOption {
 	}
 }
 
+// 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 {
@@ -246,3 +230,55 @@ func SubscribeContext(ctx context.Context) SubscribeOption {
 		o.Context = ctx
 	}
 }
+
+// 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 {
+	return func(o *SubscribeOptions) {
+		o.AutoAck = b
+	}
+}
+
+// SubscribeBodyOnly consumes only body of the message
+func SubscribeBodyOnly(b bool) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BodyOnly = b
+	}
+}
+
+// SubscribeBatchSize specifies max batch size
+func SubscribeBatchSize(n int) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchSize = n
+	}
+}
+
+// SubscribeBatchWait specifies max batch wait time
+func SubscribeBatchWait(td time.Duration) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchWait = td
+	}
+}
+
+// SubscribeOption func
+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
+}

client/client.go

@@ -40,6 +40,7 @@ type Client interface {
 	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
 }
 

client/noop.go

@@ -9,16 +9,10 @@ import (
 	"github.com/unistack-org/micro/v3/metadata"
 )
 
-var (
-	// DefaultCodecs will be used to encode/decode data
-	DefaultCodecs = map[string]codec.Codec{
-		//"application/json":         cjson.NewCodec,
-		//"application/json-rpc":     cjsonrpc.NewCodec,
-		//"application/protobuf":     cproto.NewCodec,
-		//"application/proto-rpc":    cprotorpc.NewCodec,
-		"application/octet-stream": codec.NewCodec(),
-	}
-)
+// DefaultCodecs will be used to encode/decode data
+var DefaultCodecs = map[string]codec.Codec{
+	"application/octet-stream": codec.NewCodec(),
+}
 
 type noopClient struct {
 	opts Options
@@ -179,7 +173,7 @@ func (n *noopClient) NewRequest(service, endpoint string, req interface{}, opts
 }
 
 func (n *noopClient) NewMessage(topic string, msg interface{}, opts ...MessageOption) Message {
-	options := NewMessageOptions(opts...)
+	options := NewMessageOptions(append([]MessageOption{MessageContentType(n.opts.ContentType)}, opts...)...)
 	return &noopMessage{topic: topic, payload: msg, opts: options}
 }
 
@@ -187,45 +181,60 @@ func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption
 	return &noopStream{}, nil
 }
 
-func (n *noopClient) Publish(ctx context.Context, p Message, opts ...PublishOption) error {
-	var body []byte
+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...)
 
-	md, ok := metadata.FromOutgoingContext(ctx)
-	if !ok {
-		md = metadata.New(0)
-	}
-	md["Content-Type"] = p.ContentType()
-	md["Micro-Topic"] = p.Topic()
+	msgs := make([]*broker.Message, 0, len(ps))
 
-	// 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())
+	for _, p := range ps {
+		md, ok := metadata.FromOutgoingContext(ctx)
+		if !ok {
+			md = metadata.New(0)
+		}
+		md[metadata.HeaderContentType] = p.ContentType()
+
+		topic := p.Topic()
+
+		// get the exchange
+		if len(options.Exchange) > 0 {
+			topic = options.Exchange
 		}
 
-		// set the body
-		b, err := cf.Marshal(p.Payload())
-		if err != nil {
-			return errors.InternalServerError("go.micro.client", err.Error())
+		md[metadata.HeaderTopic] = topic
+
+		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
 		}
-		body = b
+
+		msgs = append(msgs, &broker.Message{Header: md, Body: body})
 	}
 
-	topic := p.Topic()
-
-	// get the exchange
-	if len(options.Exchange) > 0 {
-		topic = options.Exchange
-	}
-
-	return n.opts.Broker.Publish(ctx, topic, &broker.Message{
-		Header: md,
-		Body:   body,
-	}, broker.PublishContext(options.Context))
+	return n.opts.Broker.BatchPublish(ctx, msgs,
+		broker.PublishContext(options.Context),
+		broker.PublishBodyOnly(options.BodyOnly),
+	)
 }

client/options.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"context"
+	"crypto/tls"
 	"time"
 
 	"github.com/unistack-org/micro/v3/broker"
@@ -18,8 +19,8 @@ import (
 
 // Options holds client options
 type Options struct {
-	// CallOptions contains default CallOptions
-	CallOptions CallOptions
+	// Selector used to select needed address
+	Selector selector.Selector
 	// Logger used to log messages
 	Logger logger.Logger
 	// Tracer used for tracing
@@ -30,24 +31,26 @@ type Options struct {
 	Meter meter.Meter
 	// Router used to get route
 	Router router.Router
-	// Selector used to select needed address
-	Selector selector.Selector
 	// Transport used for transfer messages
 	Transport transport.Transport
 	// Context is used for external options
 	Context context.Context
-	// Codecs map
-	Codecs map[string]codec.Codec
 	// Lookup func used to get destination addr
 	Lookup LookupFunc
+	// Codecs map
+	Codecs map[string]codec.Codec
+	// TLSConfig specifies tls.Config for secure connection
+	TLSConfig *tls.Config
 	// Proxy is used for proxy requests
 	Proxy string
-	// ContentType is Used to select codec
+	// ContentType is used to select codec
 	ContentType string
 	// Name is the client name
 	Name string
 	// Wrappers contains wrappers
 	Wrappers []Wrapper
+	// CallOptions contains default CallOptions
+	CallOptions CallOptions
 	// PoolSize connection pool size
 	PoolSize int
 	// PoolTTL connection pool ttl
@@ -77,6 +80,8 @@ type CallOptions struct {
 	Backoff BackoffFunc
 	// Network name
 	Network string
+	// Content-Type
+	ContentType string
 	// CallWrappers call wrappers
 	CallWrappers []CallWrapper
 	// SelectOptions selector options
@@ -91,8 +96,8 @@ type CallOptions struct {
 	RequestTimeout time.Duration
 	// DialTimeout dial timeout
 	DialTimeout time.Duration
-	// AuthToken flag
-	AuthToken bool
+	// AuthToken string
+	AuthToken string
 }
 
 // Context pass context to client
@@ -113,6 +118,8 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 
 // PublishOptions holds publish options
 type PublishOptions struct {
+	// BodyOnly will publish only message body
+	BodyOnly bool
 	// Context used for external options
 	Context context.Context
 	// Exchange topic exchange name
@@ -167,14 +174,16 @@ func NewOptions(opts ...Option) Options {
 			RequestTimeout: DefaultRequestTimeout,
 			DialTimeout:    transport.DefaultDialTimeout,
 		},
-		Lookup:   LookupRoute,
-		PoolSize: DefaultPoolSize,
-		PoolTTL:  DefaultPoolTTL,
-		Selector: random.NewSelector(),
-		Logger:   logger.DefaultLogger,
-		Broker:   broker.DefaultBroker,
-		Meter:    meter.DefaultMeter,
-		Tracer:   tracer.DefaultTracer,
+		Lookup:    LookupRoute,
+		PoolSize:  DefaultPoolSize,
+		PoolTTL:   DefaultPoolTTL,
+		Selector:  random.NewSelector(),
+		Logger:    logger.DefaultLogger,
+		Broker:    broker.DefaultBroker,
+		Meter:     meter.DefaultMeter,
+		Tracer:    tracer.DefaultTracer,
+		Router:    router.DefaultRouter,
+		Transport: transport.DefaultTransport,
 	}
 
 	for _, o := range opts {
@@ -312,6 +321,22 @@ func Lookup(l LookupFunc) Option {
 	}
 }
 
+// TLSConfig specifies a *tls.Config
+func TLSConfig(t *tls.Config) Option {
+	return func(o *Options) {
+		// set the internal tls
+		o.TLSConfig = t
+
+		// set the default transport if one is not
+		// already set. Required for Init call below.
+
+		// set the transport tls
+		o.Transport.Init(
+			transport.TLSConfig(t),
+		)
+	}
+}
+
 // Retries sets the retry count when making the request.
 func Retries(i int) Option {
 	return func(o *Options) {
@@ -348,12 +373,35 @@ func DialTimeout(d time.Duration) Option {
 }
 
 // WithExchange sets the exchange to route a message through
+// Deprecated
 func WithExchange(e string) PublishOption {
 	return func(o *PublishOptions) {
 		o.Exchange = e
 	}
 }
 
+// PublishExchange sets the exchange to route a message through
+func PublishExchange(e string) PublishOption {
+	return func(o *PublishOptions) {
+		o.Exchange = e
+	}
+}
+
+// WithBodyOnly publish only message body
+// DERECATED
+func WithBodyOnly(b bool) PublishOption {
+	return func(o *PublishOptions) {
+		o.BodyOnly = b
+	}
+}
+
+// PublishBodyOnly publish only message body
+func PublishBodyOnly(b bool) PublishOption {
+	return func(o *PublishOptions) {
+		o.BodyOnly = b
+	}
+}
+
 // PublishContext sets the context in publish options
 func PublishContext(ctx context.Context) PublishOption {
 	return func(o *PublishOptions) {
@@ -361,6 +409,13 @@ func PublishContext(ctx context.Context) PublishOption {
 	}
 }
 
+// WithContentType specifies call content type
+func WithContentType(ct string) CallOption {
+	return func(o *CallOptions) {
+		o.ContentType = ct
+	}
+}
+
 // WithAddress sets the remote addresses to use rather than using service discovery
 func WithAddress(a ...string) CallOption {
 	return func(o *CallOptions) {
@@ -424,9 +479,9 @@ func WithDialTimeout(d time.Duration) CallOption {
 
 // WithAuthToken is a CallOption which overrides the
 // authorization header with the services own auth token
-func WithAuthToken() CallOption {
+func WithAuthToken(t string) CallOption {
 	return func(o *CallOptions) {
-		o.AuthToken = true
+		o.AuthToken = t
 	}
 }
 
@@ -459,22 +514,30 @@ func WithSelectOptions(sops ...selector.SelectOption) CallOption {
 }
 
 // WithMessageContentType sets the message content type
+// Deprecated
 func WithMessageContentType(ct string) MessageOption {
 	return func(o *MessageOptions) {
 		o.ContentType = ct
 	}
 }
 
-// WithContentType specifies request content type
-func WithContentType(ct string) RequestOption {
-	return func(o *RequestOptions) {
+// MessageContentType sets the message content type
+func MessageContentType(ct string) MessageOption {
+	return func(o *MessageOptions) {
 		o.ContentType = ct
 	}
 }
 
 // StreamingRequest specifies that request is streaming
-func StreamingRequest() RequestOption {
+func StreamingRequest(b bool) RequestOption {
 	return func(o *RequestOptions) {
-		o.Stream = true
+		o.Stream = b
+	}
+}
+
+// RequestContentType specifies request content type
+func RequestContentType(ct string) RequestOption {
+	return func(o *RequestOptions) {
+		o.ContentType = ct
 	}
 }

client/test_request.go

@@ -5,13 +5,13 @@ import (
 )
 
 type testRequest struct {
-	opts        RequestOptions
 	codec       codec.Codec
 	body        interface{}
+	service     string
 	method      string
 	endpoint    string
 	contentType string
-	service     string
+	opts        RequestOptions
 }
 
 func (r *testRequest) ContentType() string {

codec/codec.go

@@ -28,6 +28,8 @@ var (
 	DefaultMaxMsgSize int = 1024 * 1024 * 4 // 4Mb
 	// DefaultCodec is the global default codec
 	DefaultCodec Codec = NewCodec()
+	// DefaultTagName specifies struct tag name to control codec Marshal/Unmarshal
+	DefaultTagName = "codec"
 )
 
 // MessageType specifies message type for codec

codec/noop.go

@@ -5,8 +5,7 @@ import (
 	"io"
 )
 
-type noopCodec struct {
-}
+type noopCodec struct{}
 
 func (c *noopCodec) ReadHeader(conn io.Reader, m *Message, t MessageType) error {
 	return nil

config/config.go

@@ -4,12 +4,17 @@ package config
 import (
 	"context"
 	"errors"
+	"time"
 )
 
-var (
-	// DefaultConfig default config
-	DefaultConfig Config = NewConfig()
-)
+// DefaultConfig default config
+var DefaultConfig Config = NewConfig()
+
+// DefaultWatcherMinInterval default min interval for poll changes
+var DefaultWatcherMinInterval = 5 * time.Second
+
+// DefaultWatcherMinInterval default max interval for poll changes
+var DefaultWatcherMaxInterval = 9 * time.Second
 
 var (
 	// ErrCodecMissing is returned when codec needed and not specified
@@ -22,34 +27,38 @@ var (
 
 // Config is an interface abstraction for dynamic configuration
 type Config interface {
+	// Name returns name of config
 	Name() string
 	// Init the config
 	Init(opts ...Option) error
 	// Options in the config
 	Options() Options
 	// Load config from sources
-	Load(context.Context) error
+	Load(context.Context, ...LoadOption) error
 	// Save config to sources
-	Save(context.Context) error
-	// Watch a value for changes
-	//	Watch(interface{}) (Watcher, error)
+	Save(context.Context, ...SaveOption) error
+	// Watch a config for changes
+	Watch(context.Context, ...WatchOption) (Watcher, error)
+	// String returns config type name
 	String() string
 }
 
 // Watcher is the config watcher
-//type Watcher interface {
-//	Next() (, error)
-//	Stop() error
-//}
+type Watcher interface {
+	// Next blocks until update happens or error returned
+	Next() (map[string]interface{}, error)
+	// Stop stops watcher
+	Stop() error
+}
 
 // Load loads config from config sources
-func Load(ctx context.Context, cs ...Config) error {
+func Load(ctx context.Context, cs []Config, opts ...LoadOption) error {
 	var err error
 	for _, c := range cs {
 		if err = c.Init(); err != nil {
 			return err
 		}
-		if err = c.Load(ctx); err != nil {
+		if err = c.Load(ctx, opts...); err != nil {
 			return err
 		}
 	}

config/default.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/imdario/mergo"
+	"github.com/unistack-org/micro/v3/util/jitter"
 	rutil "github.com/unistack-org/micro/v3/util/reflect"
 )
 
@@ -25,18 +26,31 @@ func (c *defaultConfig) Init(opts ...Option) error {
 	return nil
 }
 
-func (c *defaultConfig) Load(ctx context.Context) error {
+func (c *defaultConfig) Load(ctx context.Context, opts ...LoadOption) error {
 	for _, fn := range c.opts.BeforeLoad {
 		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
 		}
 	}
 
-	src, err := rutil.Zero(c.opts.Struct)
+	options := NewLoadOptions(opts...)
+	mopts := []func(*mergo.Config){mergo.WithTypeCheck}
+	if options.Override {
+		mopts = append(mopts, mergo.WithOverride)
+	}
+	if options.Append {
+		mopts = append(mopts, mergo.WithAppendSlice)
+	}
+
+	dst := c.opts.Struct
+	if options.Struct != nil {
+		dst = options.Struct
+	}
+
+	src, err := rutil.Zero(dst)
 	if err == nil {
-		valueOf := reflect.ValueOf(src)
-		if err = c.fillValues(ctx, valueOf); err == nil {
-			err = mergo.Merge(c.opts.Struct, src, mergo.WithOverride, mergo.WithTypeCheck, mergo.WithAppendSlice)
+		if err = fillValues(reflect.ValueOf(src), c.opts.StructTag); err == nil {
+			err = mergo.Merge(dst, src, mopts...)
 		}
 	}
 
@@ -54,7 +68,7 @@ func (c *defaultConfig) Load(ctx context.Context) error {
 }
 
 //nolint:gocyclo
-func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val string) error {
+func fillValue(value reflect.Value, val string) error {
 	if !rutil.IsEmpty(value) {
 		return nil
 	}
@@ -71,10 +85,10 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 			kv := strings.FieldsFunc(nval, func(c rune) bool { return c == '=' })
 			mkey := reflect.Indirect(reflect.New(kt))
 			mval := reflect.Indirect(reflect.New(et))
-			if err := c.fillValue(ctx, mkey, kv[0]); err != nil {
+			if err := fillValue(mkey, kv[0]); err != nil {
 				return err
 			}
-			if err := c.fillValue(ctx, mval, kv[1]); err != nil {
+			if err := fillValue(mval, kv[1]); err != nil {
 				return err
 			}
 			value.SetMapIndex(mkey, mval)
@@ -84,7 +98,7 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 		value.Set(reflect.MakeSlice(reflect.SliceOf(value.Type().Elem()), len(nvals), len(nvals)))
 		for idx, nval := range nvals {
 			nvalue := reflect.Indirect(reflect.New(value.Type().Elem()))
-			if err := c.fillValue(ctx, nvalue, nval); err != nil {
+			if err := fillValue(nvalue, nval); err != nil {
 				return err
 			}
 			value.Index(idx).Set(nvalue)
@@ -173,7 +187,7 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 	return nil
 }
 
-func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) error {
+func fillValues(valueOf reflect.Value, tname string) error {
 	var values reflect.Value
 
 	if valueOf.Kind() == reflect.Ptr {
@@ -200,7 +214,7 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 		switch value.Kind() {
 		case reflect.Struct:
 			value.Set(reflect.Indirect(reflect.New(value.Type())))
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(value, tname); err != nil {
 				return err
 			}
 			continue
@@ -214,17 +228,17 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 				value.Set(reflect.New(value.Type().Elem()))
 			}
 			value = value.Elem()
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(value, tname); err != nil {
 				return err
 			}
 			continue
 		}
-		tag, ok := field.Tag.Lookup(c.opts.StructTag)
+		tag, ok := field.Tag.Lookup(tname)
 		if !ok {
 			continue
 		}
 
-		if err := c.fillValue(ctx, value, tag); err != nil {
+		if err := fillValue(value, tag); err != nil {
 			return err
 		}
 	}
@@ -232,7 +246,7 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 	return nil
 }
 
-func (c *defaultConfig) Save(ctx context.Context) error {
+func (c *defaultConfig) Save(ctx context.Context, opts ...SaveOption) error {
 	for _, fn := range c.opts.BeforeSave {
 		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
@@ -256,6 +270,20 @@ func (c *defaultConfig) Name() string {
 	return c.opts.Name
 }
 
+func (c *defaultConfig) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) {
+	w := &defaultWatcher{
+		opts:  c.opts,
+		wopts: NewWatchOptions(opts...),
+		done:  make(chan struct{}),
+		vchan: make(chan map[string]interface{}),
+		echan: make(chan error),
+	}
+
+	go w.run()
+
+	return w, nil
+}
+
 // NewConfig returns new default config source
 func NewConfig(opts ...Option) Config {
 	options := NewOptions(opts...)
@@ -264,3 +292,76 @@ func NewConfig(opts ...Option) Config {
 	}
 	return &defaultConfig{opts: options}
 }
+
+type defaultWatcher struct {
+	opts  Options
+	wopts WatchOptions
+	done  chan struct{}
+	vchan chan map[string]interface{}
+	echan chan error
+}
+
+func (w *defaultWatcher) run() {
+	ticker := jitter.NewTicker(w.wopts.MinInterval, w.wopts.MaxInterval)
+	defer ticker.Stop()
+
+	src := w.opts.Struct
+	if w.wopts.Struct != nil {
+		src = w.wopts.Struct
+	}
+
+	for {
+		select {
+		case <-w.done:
+			return
+		case <-ticker.C:
+			dst, err := rutil.Zero(src)
+			if err == nil {
+				err = fillValues(reflect.ValueOf(dst), w.opts.StructTag)
+			}
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			srcmp, err := rutil.StructFieldsMap(src)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			dstmp, err := rutil.StructFieldsMap(dst)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			for sk, sv := range srcmp {
+				if reflect.DeepEqual(dstmp[sk], sv) {
+					delete(dstmp, sk)
+				}
+			}
+			if len(dstmp) > 0 {
+				w.vchan <- dstmp
+				src = dst
+			}
+		}
+	}
+}
+
+func (w *defaultWatcher) Next() (map[string]interface{}, error) {
+	select {
+	case <-w.done:
+		break
+	case err := <-w.echan:
+		return nil, err
+	case v, ok := <-w.vchan:
+		if !ok {
+			break
+		}
+		return v, nil
+	}
+	return nil, ErrWatcherStopped
+}
+
+func (w *defaultWatcher) Stop() error {
+	close(w.done)
+	return nil
+}

config/default_test.go

@@ -4,36 +4,88 @@ import (
 	"context"
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/unistack-org/micro/v3/config"
 )
 
 type Cfg struct {
 	StringValue string `default:"string_value"`
-	IntValue    int    `default:"99"`
 	IgnoreValue string `json:"-"`
 	StructValue struct {
 		StringValue string `default:"string_value"`
 	}
+	IntValue int `default:"99"`
+}
+
+func TestWatch(t *testing.T) {
+	ctx := context.Background()
+
+	conf := &Cfg{IntValue: 10}
+
+	cfg := config.NewConfig(config.Struct(conf))
+	if err := cfg.Init(); err != nil {
+		t.Fatal(err)
+	}
+	if err := cfg.Load(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	w, err := cfg.Watch(ctx, config.WatchInterval(200*time.Millisecond, 500*time.Millisecond))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		_ = w.Stop()
+	}()
+
+	done := make(chan struct{})
+
+	go func() {
+		for {
+			mp, err := w.Next()
+			if err != nil && err != config.ErrWatcherStopped {
+				t.Fatal(err)
+			} else if err == config.ErrWatcherStopped {
+				return
+			}
+			if len(mp) != 1 {
+				t.Fatal(fmt.Errorf("default watcher err: %v", mp))
+			}
+
+			v, ok := mp["IntValue"]
+			if !ok {
+				t.Fatal(fmt.Errorf("default watcher err: %v", v))
+			}
+			if nv, ok := v.(int); !ok || nv != 99 {
+				t.Fatal(fmt.Errorf("default watcher err: %v", v))
+			}
+			close(done)
+			return
+		}
+	}()
+
+	<-done
 }
 
 func TestDefault(t *testing.T) {
 	ctx := context.Background()
 	conf := &Cfg{IntValue: 10}
 	blfn := func(ctx context.Context, cfg config.Config) error {
-		conf, ok := cfg.Options().Struct.(*Cfg)
+		nconf, ok := cfg.Options().Struct.(*Cfg)
 		if !ok {
 			return fmt.Errorf("failed to get Struct from options: %v", cfg.Options())
 		}
-		conf.StringValue = "before_load"
+		nconf.StringValue = "before_load"
 		return nil
 	}
 	alfn := func(ctx context.Context, cfg config.Config) error {
-		conf, ok := cfg.Options().Struct.(*Cfg)
+		nconf, ok := cfg.Options().Struct.(*Cfg)
 		if !ok {
 			return fmt.Errorf("failed to get Struct from options: %v", cfg.Options())
 		}
-		conf.StringValue = "after_load"
+		nconf.StringValue = "after_load"
 		return nil
 	}
 
@@ -47,6 +99,6 @@ func TestDefault(t *testing.T) {
 	if conf.StringValue != "after_load" {
 		t.Fatal("AfterLoad option not working")
 	}
-
-	t.Logf("%#+v\n", conf)
+	_ = conf
+	//t.Logf("%#+v\n", conf)
 }

config/options.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"context"
+	"time"
 
 	"github.com/unistack-org/micro/v3/codec"
 	"github.com/unistack-org/micro/v3/logger"
@@ -57,6 +58,69 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// LoadOption function signature
+type LoadOption func(o *LoadOptions)
+
+// LoadOptions struct
+type LoadOptions struct {
+	Struct   interface{}
+	Override bool
+	Append   bool
+}
+
+func NewLoadOptions(opts ...LoadOption) LoadOptions {
+	options := LoadOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// LoadOverride override values when load
+func LoadOverride(b bool) LoadOption {
+	return func(o *LoadOptions) {
+		o.Override = b
+	}
+}
+
+// LoadAppend override values when load
+func LoadAppend(b bool) LoadOption {
+	return func(o *LoadOptions) {
+		o.Append = b
+	}
+}
+
+// LoadStruct override struct for loading
+func LoadStruct(src interface{}) LoadOption {
+	return func(o *LoadOptions) {
+		o.Struct = src
+	}
+}
+
+// SaveOption function signature
+type SaveOption func(o *SaveOptions)
+
+// SaveOptions struct
+type SaveOptions struct {
+	Struct interface{}
+}
+
+// SaveStruct override struct for save to config
+func SaveStruct(src interface{}) SaveOption {
+	return func(o *SaveOptions) {
+		o.Struct = src
+	}
+}
+
+// NewSaveOptions fill SaveOptions struct
+func NewSaveOptions(opts ...SaveOption) SaveOptions {
+	options := SaveOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
 // AllowFail allows config source to fail
 func AllowFail(b bool) Option {
 	return func(o *Options) {
@@ -140,3 +204,60 @@ func Name(n string) Option {
 		o.Name = n
 	}
 }
+
+// WatchOptions struuct
+type WatchOptions struct {
+	// Context used by non default options
+	Context context.Context
+	// Coalesce multiple events to one
+	Coalesce bool
+	// MinInterval specifies the min time.Duration interval for poll changes
+	MinInterval time.Duration
+	// MaxInterval specifies the max time.Duration interval for poll changes
+	MaxInterval time.Duration
+	// Struct for filling
+	Struct interface{}
+}
+
+type WatchOption func(*WatchOptions)
+
+func NewWatchOptions(opts ...WatchOption) WatchOptions {
+	options := WatchOptions{
+		Context:     context.Background(),
+		MinInterval: DefaultWatcherMinInterval,
+		MaxInterval: DefaultWatcherMaxInterval,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// WatchContext pass context
+func WatchContext(ctx context.Context) WatchOption {
+	return func(o *WatchOptions) {
+		o.Context = ctx
+	}
+}
+
+// WatchCoalesce controls watch event combining
+func WatchCoalesce(b bool) WatchOption {
+	return func(o *WatchOptions) {
+		o.Coalesce = b
+	}
+}
+
+// WatchInterval specifies min and max time.Duration for pulling changes
+func WatchInterval(min, max time.Duration) WatchOption {
+	return func(o *WatchOptions) {
+		o.MinInterval = min
+		o.MaxInterval = max
+	}
+}
+
+// WatchStruct overrides struct for fill
+func WatchStruct(src interface{}) WatchOption {
+	return func(o *WatchOptions) {
+		o.Struct = src
+	}
+}

config/reflect_test.go

@@ -1,26 +0,0 @@
-package config_test
-
-import (
-	"testing"
-
-	rutil "github.com/unistack-org/micro/v3/util/reflect"
-)
-
-type Config struct {
-	Value     string
-	SubConfig *SubConfig
-	Config    *Config
-}
-
-type SubConfig struct {
-	Value string
-}
-
-func TestReflect(t *testing.T) {
-	cfg1 := &Config{Value: "cfg1", Config: &Config{Value: "cfg1_1"}, SubConfig: &SubConfig{Value: "cfg1"}}
-	cfg2, err := rutil.Zero(cfg1)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("dst: %#+v\n", cfg2)
-}

errors/errors_test.go

@@ -17,7 +17,6 @@ func TestFromError(t *testing.T) {
 	if merr.Id != "go.micro.test" || merr.Code != 404 {
 		t.Fatalf("invalid conversation %v != %v", err, merr)
 	}
-
 }
 
 func TestEqual(t *testing.T) {
@@ -32,7 +31,6 @@ func TestEqual(t *testing.T) {
 	if Equal(err1, err3) {
 		t.Fatal("errors must be not equal")
 	}
-
 }
 
 func TestErrors(t *testing.T) {

flow/context.go

@@ -0,0 +1,34 @@
+package flow
+
+import (
+	"context"
+)
+
+type flowKey struct{}
+
+// FromContext returns Flow from context
+func FromContext(ctx context.Context) (Flow, bool) {
+	if ctx == nil {
+		return nil, false
+	}
+	c, ok := ctx.Value(flowKey{}).(Flow)
+	return c, ok
+}
+
+// NewContext stores Flow to context
+func NewContext(ctx context.Context, f Flow) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, flowKey{}, f)
+}
+
+// SetOption returns a function to setup a context with given value
+func SetOption(k, v interface{}) Option {
+	return func(o *Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

flow/dag_test.go

@@ -44,10 +44,10 @@ func TestDag(t *testing.T) {
 	var steps [][]string
 	fn := func(n dag.Vertex, idx int) error {
 		if idx == 0 {
-			steps = make([][]string, 1, 1)
+			steps = make([][]string, 1)
 			steps[0] = make([]string, 0, 1)
 		} else if idx >= len(steps) {
-			tsteps := make([][]string, idx+1, idx+1)
+			tsteps := make([][]string, idx+1)
 			copy(tsteps, steps)
 			steps = tsteps
 			steps[idx] = make([]string, 0, 1)

flow/default.go

@@ -0,0 +1,588 @@
+package flow
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"sync"
+
+	"github.com/google/uuid"
+	"github.com/silas/dag"
+	"github.com/unistack-org/micro/v3/client"
+	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/logger"
+	"github.com/unistack-org/micro/v3/metadata"
+	"github.com/unistack-org/micro/v3/store"
+)
+
+type microFlow struct {
+	opts Options
+}
+
+type microWorkflow struct {
+	id   string
+	g    *dag.AcyclicGraph
+	init bool
+	sync.RWMutex
+	opts   Options
+	steps  map[string]Step
+	status Status
+}
+
+func (w *microWorkflow) ID() string {
+	return w.id
+}
+
+func (w *microWorkflow) Steps() ([][]Step, error) {
+	return w.getSteps("", false)
+}
+
+func (w *microWorkflow) Status() Status {
+	return w.status
+}
+
+func (w *microWorkflow) AppendSteps(steps ...Step) error {
+	w.Lock()
+
+	for _, s := range steps {
+		w.steps[s.String()] = s
+		w.g.Add(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		w.Unlock()
+		return err
+	}
+
+	w.g.TransitiveReduction()
+
+	w.Unlock()
+
+	return nil
+}
+
+func (w *microWorkflow) RemoveSteps(steps ...Step) error {
+	// TODO: handle case when some step requires or required by removed step
+
+	w.Lock()
+
+	for _, s := range steps {
+		delete(w.steps, s.String())
+		w.g.Remove(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		w.Unlock()
+		return err
+	}
+
+	w.g.TransitiveReduction()
+
+	w.Unlock()
+
+	return nil
+}
+
+func (w *microWorkflow) getSteps(start string, reverse bool) ([][]Step, error) {
+	var steps [][]Step
+	var root dag.Vertex
+	var err error
+
+	fn := func(n dag.Vertex, idx int) error {
+		if idx == 0 {
+			steps = make([][]Step, 1)
+			steps[0] = make([]Step, 0, 1)
+		} else if idx >= len(steps) {
+			tsteps := make([][]Step, idx+1)
+			copy(tsteps, steps)
+			steps = tsteps
+			steps[idx] = make([]Step, 0, 1)
+		}
+		steps[idx] = append(steps[idx], n.(Step))
+		return nil
+	}
+
+	if start != "" {
+		var ok bool
+		w.RLock()
+		root, ok = w.steps[start]
+		w.RUnlock()
+		if !ok {
+			return nil, ErrStepNotExists
+		}
+	} else {
+		root, err = w.g.Root()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if reverse {
+		err = w.g.SortedReverseDepthFirstWalk([]dag.Vertex{root}, fn)
+	} else {
+		err = w.g.SortedDepthFirstWalk([]dag.Vertex{root}, fn)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return steps, nil
+}
+
+func (w *microWorkflow) Abort(ctx context.Context, eid string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusAborted.String())})
+}
+
+func (w *microWorkflow) Suspend(ctx context.Context, eid string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusSuspend.String())})
+}
+
+func (w *microWorkflow) Resume(ctx context.Context, eid string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusRunning.String())})
+}
+
+func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (string, error) {
+	w.Lock()
+	if !w.init {
+		if err := w.g.Validate(); err != nil {
+			w.Unlock()
+			return "", err
+		}
+		w.g.TransitiveReduction()
+		w.init = true
+	}
+	w.Unlock()
+
+	uid, err := uuid.NewRandom()
+	if err != nil {
+		return "", err
+	}
+	eid := uid.String()
+
+	stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
+
+	options := NewExecuteOptions(opts...)
+
+	steps, err := w.getSteps(options.Start, options.Reverse)
+	if err != nil {
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+		return "", err
+	}
+
+	var wg sync.WaitGroup
+	cherr := make(chan error, 1)
+	chstatus := make(chan Status, 1)
+
+	nctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	nopts := make([]ExecuteOption, 0, len(opts)+5)
+
+	nopts = append(nopts,
+		ExecuteClient(w.opts.Client),
+		ExecuteTracer(w.opts.Tracer),
+		ExecuteLogger(w.opts.Logger),
+		ExecuteMeter(w.opts.Meter),
+	)
+	nopts = append(nopts, opts...)
+	done := make(chan struct{})
+
+	if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+		w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		return eid, werr
+	}
+	for idx := range steps {
+		for nidx := range steps[idx] {
+			cstep := steps[idx][nidx]
+			if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
+				return eid, werr
+			}
+		}
+	}
+
+	go func() {
+		for idx := range steps {
+			for nidx := range steps[idx] {
+				wStatus := &codec.Frame{}
+				if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
+					cherr <- werr
+					return
+				}
+				if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
+					chstatus <- status
+					return
+				}
+				if w.opts.Logger.V(logger.TraceLevel) {
+					w.opts.Logger.Tracef(nctx, "will be executed %v", steps[idx][nidx])
+				}
+				cstep := steps[idx][nidx]
+				if len(cstep.Requires()) == 0 {
+					wg.Add(1)
+					go func(step Step) {
+						defer wg.Done()
+						if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "req"), req); werr != nil {
+							cherr <- werr
+							return
+						}
+						if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+							cherr <- werr
+							return
+						}
+						rsp, serr := step.Execute(nctx, req, nopts...)
+						if serr != nil {
+							step.SetStatus(StatusFailure)
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							}
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							}
+							cherr <- serr
+							return
+						} else {
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), rsp); werr != nil {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								cherr <- werr
+								return
+							}
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								cherr <- werr
+								return
+							}
+						}
+					}(cstep)
+					wg.Wait()
+				} else {
+					if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "req"), req); werr != nil {
+						cherr <- werr
+						return
+					}
+					if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+						cherr <- werr
+						return
+					}
+					rsp, serr := cstep.Execute(nctx, req, nopts...)
+					if serr != nil {
+						cstep.SetStatus(StatusFailure)
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+						}
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+						}
+						cherr <- serr
+						return
+					} else {
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), rsp); werr != nil {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							cherr <- werr
+							return
+						}
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+							cherr <- werr
+							return
+						}
+					}
+				}
+			}
+		}
+		close(done)
+	}()
+
+	if options.Async {
+		return eid, nil
+	}
+
+	logger.Tracef(ctx, "wait for finish or error")
+	select {
+	case <-nctx.Done():
+		err = nctx.Err()
+	case cerr := <-cherr:
+		err = cerr
+	case <-done:
+		close(cherr)
+	case <-chstatus:
+		close(chstatus)
+		return uid.String(), nil
+	}
+
+	switch {
+	case nctx.Err() != nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+		break
+	case err == nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+		break
+	case err != nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+		break
+	}
+
+	return uid.String(), err
+}
+
+func NewFlow(opts ...Option) Flow {
+	options := NewOptions(opts...)
+	return &microFlow{opts: options}
+}
+
+func (f *microFlow) Options() Options {
+	return f.opts
+}
+
+func (f *microFlow) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&f.opts)
+	}
+	if err := f.opts.Client.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Tracer.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Logger.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Meter.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Store.Init(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (f *microFlow) WorkflowList(ctx context.Context) ([]Workflow, error) {
+	return nil, nil
+}
+
+func (f *microFlow) WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error) {
+	w := &microWorkflow{opts: f.opts, id: id, g: &dag.AcyclicGraph{}, steps: make(map[string]Step, len(steps))}
+
+	for _, s := range steps {
+		w.steps[s.String()] = s
+		w.g.Add(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return nil, ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		return nil, err
+	}
+	w.g.TransitiveReduction()
+
+	w.init = true
+
+	return w, nil
+}
+
+func (f *microFlow) WorkflowRemove(ctx context.Context, id string) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowSave(ctx context.Context, w Workflow) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowLoad(ctx context.Context, id string) (Workflow, error) {
+	return nil, nil
+}
+
+type microCallStep struct {
+	opts    StepOptions
+	service string
+	method  string
+	rsp     *Message
+	req     *Message
+	status  Status
+}
+
+func (s *microCallStep) Request() *Message {
+	return s.req
+}
+
+func (s *microCallStep) Response() *Message {
+	return s.rsp
+}
+
+func (s *microCallStep) ID() string {
+	return s.String()
+}
+
+func (s *microCallStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microCallStep) Endpoint() string {
+	return s.method
+}
+
+func (s *microCallStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microCallStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microCallStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return fmt.Sprintf("%s.%s", s.service, s.method)
+}
+
+func (s *microCallStep) Name() string {
+	return s.String()
+}
+
+func (s *microCallStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microCallStep) GetStatus() Status {
+	return s.status
+}
+
+func (s *microCallStep) SetStatus(status Status) {
+	s.status = status
+}
+
+func (s *microCallStep) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error) {
+	options := NewExecuteOptions(opts...)
+	if options.Client == nil {
+		return nil, ErrMissingClient
+	}
+	rsp := &codec.Frame{}
+	copts := []client.CallOption{client.WithRetries(0)}
+	if options.Timeout > 0 {
+		copts = append(copts, client.WithRequestTimeout(options.Timeout), client.WithDialTimeout(options.Timeout))
+	}
+	nctx := metadata.NewOutgoingContext(ctx, req.Header)
+	err := options.Client.Call(nctx, options.Client.NewRequest(s.service, s.method, &codec.Frame{Data: req.Body}), rsp)
+	if err != nil {
+		return nil, err
+	}
+	md, _ := metadata.FromOutgoingContext(nctx)
+	return &Message{Header: md, Body: rsp.Data}, err
+}
+
+type microPublishStep struct {
+	opts   StepOptions
+	topic  string
+	req    *Message
+	rsp    *Message
+	status Status
+}
+
+func (s *microPublishStep) Request() *Message {
+	return s.req
+}
+
+func (s *microPublishStep) Response() *Message {
+	return s.rsp
+}
+
+func (s *microPublishStep) ID() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microPublishStep) Endpoint() string {
+	return s.topic
+}
+
+func (s *microPublishStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microPublishStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microPublishStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return fmt.Sprintf("%s", s.topic)
+}
+
+func (s *microPublishStep) Name() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microPublishStep) GetStatus() Status {
+	return s.status
+}
+
+func (s *microPublishStep) SetStatus(status Status) {
+	s.status = status
+}
+
+func (s *microPublishStep) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error) {
+	return nil, nil
+}
+
+func NewCallStep(service string, name string, method string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microCallStep{service: service, method: name + "." + method, opts: options}
+}
+
+func NewPublishStep(topic string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microPublishStep{topic: topic, opts: options}
+}

flow/flow.go

@@ -1,7 +1,152 @@
-// Package flow is an interface used for saga pattern messaging
+// Package flow is an interface used for saga pattern microservice workflow
 package flow
 
-type Step interface {
-	// Endpoint returns service_name.service_method
-	Endpoint() string
+import (
+	"context"
+	"errors"
+	"sync"
+	"sync/atomic"
+
+	"github.com/unistack-org/micro/v3/metadata"
+)
+
+var (
+	ErrStepNotExists = errors.New("step not exists")
+	ErrMissingClient = errors.New("client not set")
+)
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}
+
+type Message struct {
+	Header metadata.Metadata
+	Body   RawMessage
+}
+
+// Step represents dedicated workflow step
+type Step interface {
+	// ID returns step id
+	ID() string
+	// Endpoint returns rpc endpoint service_name.service_method or broker topic
+	Endpoint() string
+	// Execute step run
+	Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error)
+	// Requires returns dependent steps
+	Requires() []string
+	// Options returns step options
+	Options() StepOptions
+	// Require add required steps
+	Require(steps ...Step) error
+	// String
+	String() string
+	// GetStatus returns step status
+	GetStatus() Status
+	// SetStatus sets the step status
+	SetStatus(Status)
+	// Request returns step request message
+	Request() *Message
+	// Response returns step response message
+	Response() *Message
+}
+
+type Status int
+
+func (status Status) String() string {
+	return StatusString[status]
+}
+
+const (
+	StatusPending Status = iota
+	StatusRunning
+	StatusFailure
+	StatusSuccess
+	StatusAborted
+	StatusSuspend
+)
+
+var (
+	StatusString = map[Status]string{
+		StatusPending: "StatusPending",
+		StatusRunning: "StatusRunning",
+		StatusFailure: "StatusFailure",
+		StatusSuccess: "StatusSuccess",
+		StatusAborted: "StatusAborted",
+		StatusSuspend: "StatusSuspend",
+	}
+	StringStatus = map[string]Status{
+		"StatusPending": StatusPending,
+		"StatusRunning": StatusRunning,
+		"StatusFailure": StatusFailure,
+		"StatusSuccess": StatusSuccess,
+		"StatusAborted": StatusAborted,
+		"StatusSuspend": StatusSuspend,
+	}
+)
+
+// Workflow contains all steps to execute
+type Workflow interface {
+	// ID returns id of the workflow
+	ID() string
+	// Execute workflow with args, return execution id and error
+	Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (string, error)
+	// RemoveSteps remove steps from workflow
+	RemoveSteps(steps ...Step) error
+	// AppendSteps append steps to workflow
+	AppendSteps(steps ...Step) error
+	// Status returns workflow status
+	Status() Status
+	// Steps returns steps slice where parallel steps returned on the same level
+	Steps() ([][]Step, error)
+	// Suspend suspends execution
+	Suspend(ctx context.Context, eid string) error
+	// Resume resumes execution
+	Resume(ctx context.Context, eid string) error
+	// Abort abort execution
+	Abort(ctx context.Context, eid string) error
+}
+
+// Flow the base interface to interact with workflows
+type Flow interface {
+	// Options returns options
+	Options() Options
+	// Init initialize
+	Init(...Option) error
+	// WorkflowCreate creates new workflow with specific id and steps
+	WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error)
+	// WorkflowSave saves workflow
+	WorkflowSave(ctx context.Context, w Workflow) error
+	// WorkflowLoad loads workflow with specific id
+	WorkflowLoad(ctx context.Context, id string) (Workflow, error)
+	// WorkflowList lists all workflows
+	WorkflowList(ctx context.Context) ([]Workflow, error)
+}
+
+var (
+	flowMu      sync.Mutex
+	atomicSteps atomic.Value
+)
+
+func RegisterStep(step Step) {
+	flowMu.Lock()
+	steps, _ := atomicSteps.Load().([]Step)
+	atomicSteps.Store(append(steps, step))
+	flowMu.Unlock()
 }

flow/options.go

@@ -0,0 +1,230 @@
+package flow
+
+import (
+	"context"
+	"time"
+
+	"github.com/unistack-org/micro/v3/client"
+	"github.com/unistack-org/micro/v3/logger"
+	"github.com/unistack-org/micro/v3/meter"
+	"github.com/unistack-org/micro/v3/store"
+	"github.com/unistack-org/micro/v3/tracer"
+)
+
+// Option func
+type Option func(*Options)
+
+// Options server struct
+type Options struct {
+	// Context holds the external options and can be used for flow shutdown
+	Context context.Context
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Store used for intermediate results
+	Store store.Store
+}
+
+// NewOptions returns new options struct with default or passed values
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		Context: context.Background(),
+		Logger:  logger.DefaultLogger,
+		Meter:   meter.DefaultMeter,
+		Tracer:  tracer.DefaultTracer,
+		Client:  client.DefaultClient,
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return options
+}
+
+// Logger sets the logger option
+func Logger(l logger.Logger) Option {
+	return func(o *Options) {
+		o.Logger = l
+	}
+}
+
+// Meter sets the meter option
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+// Client to use for sync/async communication
+func Client(c client.Client) Option {
+	return func(o *Options) {
+		o.Client = c
+	}
+}
+
+// Context specifies a context for the service.
+// Can be used to signal shutdown of the flow
+// Can be used for extra option values.
+func Context(ctx context.Context) Option {
+	return func(o *Options) {
+		o.Context = ctx
+	}
+}
+
+// Tracer mechanism for distributed tracking
+func Tracer(t tracer.Tracer) Option {
+	return func(o *Options) {
+		o.Tracer = t
+	}
+}
+
+// Store used for intermediate results
+func Store(s store.Store) Option {
+	return func(o *Options) {
+		o.Store = s
+	}
+}
+
+// WorflowOption signature
+type WorkflowOption func(*WorkflowOptions)
+
+// WorkflowOptions holds workflow options
+type WorkflowOptions struct {
+	ID      string
+	Context context.Context
+}
+
+// WorkflowID set workflow id
+func WorkflowID(id string) WorkflowOption {
+	return func(o *WorkflowOptions) {
+		o.ID = id
+	}
+}
+
+type ExecuteOptions struct {
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Context can be used to abort execution or pass additional opts
+	Context context.Context
+	// Start step
+	Start string
+	// Reverse execution
+	Reverse bool
+	// Timeout for execution
+	Timeout time.Duration
+	// Async enables async execution
+	Async bool
+}
+
+type ExecuteOption func(*ExecuteOptions)
+
+func ExecuteClient(c client.Client) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Client = c
+	}
+}
+
+func ExecuteTracer(t tracer.Tracer) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Tracer = t
+	}
+}
+
+func ExecuteLogger(l logger.Logger) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Logger = l
+	}
+}
+
+func ExecuteMeter(m meter.Meter) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Meter = m
+	}
+}
+
+func ExecuteContext(ctx context.Context) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Context = ctx
+	}
+}
+
+func ExecuteReverse(b bool) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Reverse = b
+	}
+}
+
+func ExecuteTimeout(td time.Duration) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Timeout = td
+	}
+}
+
+func ExecuteAsync(b bool) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Async = b
+	}
+}
+
+func NewExecuteOptions(opts ...ExecuteOption) ExecuteOptions {
+	options := ExecuteOptions{
+		Client:  client.DefaultClient,
+		Logger:  logger.DefaultLogger,
+		Tracer:  tracer.DefaultTracer,
+		Meter:   meter.DefaultMeter,
+		Context: context.Background(),
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+type StepOptions struct {
+	ID       string
+	Context  context.Context
+	Requires []string
+	Fallback string
+}
+
+type StepOption func(*StepOptions)
+
+func NewStepOptions(opts ...StepOption) StepOptions {
+	options := StepOptions{
+		Context: context.Background(),
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+func StepID(id string) StepOption {
+	return func(o *StepOptions) {
+		o.ID = id
+	}
+}
+
+func StepRequires(steps ...string) StepOption {
+	return func(o *StepOptions) {
+		o.Requires = steps
+	}
+}
+
+func StepFallback(step string) StepOption {
+	return func(o *StepOptions) {
+		o.Fallback = step
+	}
+}

generate.go

@@ -1,3 +0,0 @@
-package micro
-
-//go:generate ./.github/generate.sh

go.mod

@@ -3,11 +3,11 @@ module github.com/unistack-org/micro/v3
 go 1.16
 
 require (
-	github.com/dgrijalva/jwt-go v3.2.0+incompatible
 	github.com/ef-ds/deque v1.0.4
-	github.com/google/uuid v1.2.0
+	github.com/golang-jwt/jwt v3.2.2+incompatible
+	github.com/google/uuid v1.3.0
 	github.com/imdario/mergo v0.3.12
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20210121180416-41cf55125c34
-	golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4
+	golang.org/x/net v0.0.0-20210510120150-4163338589ed
 )

go.sum

@@ -1,21 +1,21 @@
-github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
-github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/ef-ds/deque v1.0.4 h1:iFAZNmveMT9WERAkqLJ+oaABF9AcVQ5AjXem/hroniI=
 github.com/ef-ds/deque v1.0.4/go.mod h1:gXDnTC3yqvBcHbq2lcExjtAcVrOnJCbMcZXmuj8Z4tg=
-github.com/google/uuid v1.2.0 h1:qJYtXnJRWmpe7m/3XlyhrsLrEURqHRM2kxzoxXqyUDs=
-github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
+github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/silas/dag v0.0.0-20210121180416-41cf55125c34 h1:vBfVmA5mZhsQa2jr1FOL9nfA37N/jnbBmi5XUfviVTI=
 github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4 h1:b0LrWgu8+q7z4J+0Y3Umo5q1dL7NXBkKBWkaVkAq17E=
-golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
+golang.org/x/net v0.0.0-20210510120150-4163338589ed h1:p9UgmWI9wKpfYmgaV/IZKGdXc5qEK45tDwwwDyjS26I=
+golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=

logger/default.go

@@ -21,9 +21,11 @@ func init() {
 }
 
 type defaultLogger struct {
-	opts Options
 	enc  *json.Encoder
+	opts Options
 	sync.RWMutex
+	logFunc  LogFunc
+	logfFunc LogfFunc
 }
 
 // Init(opts...) should only overwrite provided options
@@ -33,6 +35,12 @@ func (l *defaultLogger) Init(opts ...Option) error {
 		o(&l.opts)
 	}
 	l.enc = json.NewEncoder(l.opts.Out)
+	// wrap the Log func
+	for i := len(l.opts.Wrappers); i > 0; i-- {
+		l.logFunc = l.opts.Wrappers[i-1].Log(l.logFunc)
+		l.logfFunc = l.opts.Wrappers[i-1].Logf(l.logfFunc)
+	}
+
 	l.Unlock()
 	return nil
 }
@@ -121,27 +129,27 @@ func (l *defaultLogger) Fatal(ctx context.Context, args ...interface{}) {
 }
 
 func (l *defaultLogger) Infof(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, InfoLevel, msg, args...)
+	l.logfFunc(ctx, InfoLevel, msg, args...)
 }
 
 func (l *defaultLogger) Errorf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, ErrorLevel, msg, args...)
+	l.logfFunc(ctx, ErrorLevel, msg, args...)
 }
 
 func (l *defaultLogger) Debugf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, DebugLevel, msg, args...)
+	l.logfFunc(ctx, DebugLevel, msg, args...)
 }
 
 func (l *defaultLogger) Warnf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, WarnLevel, msg, args...)
+	l.logfFunc(ctx, WarnLevel, msg, args...)
 }
 
 func (l *defaultLogger) Tracef(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, TraceLevel, msg, args...)
+	l.logfFunc(ctx, TraceLevel, msg, args...)
 }
 
 func (l *defaultLogger) Fatalf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, FatalLevel, msg, args...)
+	l.logfFunc(ctx, FatalLevel, msg, args...)
 	os.Exit(1)
 }
 
@@ -207,7 +215,11 @@ func (l *defaultLogger) Options() Options {
 
 // NewLogger builds a new logger based on options
 func NewLogger(opts ...Option) Logger {
-	l := &defaultLogger{opts: NewOptions(opts...)}
+	l := &defaultLogger{
+		opts: NewOptions(opts...),
+	}
+	l.logFunc = l.Log
+	l.logfFunc = l.Logf
 	l.enc = json.NewEncoder(l.opts.Out)
 	return l
 }

logger/logger.go

@@ -8,6 +8,8 @@ var (
 	DefaultLogger Logger = NewLogger()
 	// DefaultLevel used by logger
 	DefaultLevel Level = InfoLevel
+	// DefaultCallerSkipCount used by logger
+	DefaultCallerSkipCount = 2
 )
 
 // Logger is a generic logging interface

logger/logger_test.go

@@ -1,13 +1,15 @@
 package logger
 
 import (
+	"bytes"
 	"context"
 	"testing"
 )
 
 func TestLogger(t *testing.T) {
 	ctx := context.TODO()
-	l := NewLogger(WithLevel(TraceLevel))
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(WithLevel(TraceLevel), WithOutput(buf))
 	if err := l.Init(); err != nil {
 		t.Fatal(err)
 	}
@@ -15,4 +17,52 @@ func TestLogger(t *testing.T) {
 	l.Warn(ctx, "warn_msg1")
 	l.Fields(map[string]interface{}{"error": "test"}).Info(ctx, "error message")
 	l.Warn(ctx, "first", " ", "second")
+	if !bytes.Contains(buf.Bytes(), []byte(`"level":"trace","msg":"trace_msg1"`)) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte(`"warn","msg":"warn_msg1"`)) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte(`"error":"test","level":"info","msg":"error message"`)) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte(`"level":"warn","msg":"first second"`)) {
+		t.Fatalf("logger error, buf %s", buf.Bytes())
+	}
+}
+
+func TestLoggerWrapper(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(WithLevel(TraceLevel), WithOutput(buf))
+	if err := l.Init(WrapLogger(NewOmitWrapper())); err != nil {
+		t.Fatal(err)
+	}
+	type secret struct {
+		Name  string
+		Passw string `logger:"omit"`
+	}
+	s := &secret{Name: "name", Passw: "secret"}
+	l.Errorf(ctx, "test %#+v", s)
+	if !bytes.Contains(buf.Bytes(), []byte(`logger.secret{Name:\"name\", Passw:\"\"}"`)) {
+		t.Fatalf("omit not works, struct: %v, output: %s", s, buf.Bytes())
+	}
+}
+
+func TestOmitLoggerWrapper(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewOmitLogger(NewLogger(WithLevel(TraceLevel), WithOutput(buf)))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	type secret struct {
+		Name  string
+		Passw string `logger:"omit"`
+	}
+	s := &secret{Name: "name", Passw: "secret"}
+	l.Errorf(ctx, "test %#+v", s)
+	if !bytes.Contains(buf.Bytes(), []byte(`logger.secret{Name:\"name\", Passw:\"\"}"`)) {
+		t.Fatalf("omit not works, struct: %v, output: %s", s, buf.Bytes())
+	}
 }

logger/options.go

@@ -23,6 +23,8 @@ type Options struct {
 	CallerSkipCount int
 	// The logging level the logger should log
 	Level Level
+	// Wrappers logger wrapper that called before actual Log/Logf function
+	Wrappers []Wrapper
 }
 
 // NewOptions creates new options struct
@@ -31,7 +33,7 @@ func NewOptions(opts ...Option) Options {
 		Level:           DefaultLevel,
 		Fields:          make(map[string]interface{}),
 		Out:             os.Stderr,
-		CallerSkipCount: 0,
+		CallerSkipCount: DefaultCallerSkipCount,
 		Context:         context.Background(),
 	}
 	for _, o := range opts {
@@ -76,8 +78,15 @@ func WithContext(ctx context.Context) Option {
 }
 
 // WithName sets the name
-func withName(n string) Option {
+func WithName(n string) Option {
 	return func(o *Options) {
 		o.Name = n
 	}
 }
+
+// WrapLogger adds a logger Wrapper to a list of options passed into the logger
+func WrapLogger(w Wrapper) Option {
+	return func(o *Options) {
+		o.Wrappers = append(o.Wrappers, w)
+	}
+}

logger/wrapper.go

@@ -0,0 +1,154 @@
+package logger
+
+import (
+	"context"
+	"reflect"
+
+	rutil "github.com/unistack-org/micro/v3/util/reflect"
+)
+
+// LogFunc function used for Log method
+type LogFunc func(ctx context.Context, level Level, args ...interface{})
+
+// LogfFunc function used for Logf method
+type LogfFunc func(ctx context.Context, level Level, msg string, args ...interface{})
+
+type Wrapper interface {
+	// Log logs message with needed level
+	Log(LogFunc) LogFunc
+	// Logf logs message with needed level
+	Logf(LogfFunc) LogfFunc
+}
+
+var (
+	_ Logger = &OmitLogger{}
+)
+
+type OmitLogger struct {
+	l Logger
+}
+
+func NewOmitLogger(l Logger) Logger {
+	return &OmitLogger{l: l}
+}
+
+func (w *OmitLogger) Init(opts ...Option) error {
+	return w.l.Init(append(opts, WrapLogger(NewOmitWrapper()))...)
+}
+
+func (w *OmitLogger) V(level Level) bool {
+	return w.l.V(level)
+}
+
+func (w *OmitLogger) Options() Options {
+	return w.l.Options()
+}
+
+func (w *OmitLogger) Fields(fields map[string]interface{}) Logger {
+	return w.l.Fields(fields)
+}
+
+func (w *OmitLogger) Info(ctx context.Context, args ...interface{}) {
+	w.l.Info(ctx, args...)
+}
+
+func (w *OmitLogger) Trace(ctx context.Context, args ...interface{}) {
+	w.l.Trace(ctx, args...)
+}
+
+func (w *OmitLogger) Debug(ctx context.Context, args ...interface{}) {
+	w.l.Debug(ctx, args...)
+}
+
+func (w *OmitLogger) Warn(ctx context.Context, args ...interface{}) {
+	w.l.Warn(ctx, args...)
+}
+
+func (w *OmitLogger) Error(ctx context.Context, args ...interface{}) {
+	w.l.Error(ctx, args...)
+}
+
+func (w *OmitLogger) Fatal(ctx context.Context, args ...interface{}) {
+	w.l.Fatal(ctx, args...)
+}
+
+func (w *OmitLogger) Infof(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Infof(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Tracef(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Tracef(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Debugf(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Debugf(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Warnf(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Warnf(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Errorf(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Errorf(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Fatalf(ctx context.Context, msg string, args ...interface{}) {
+	w.l.Fatalf(ctx, msg, args...)
+}
+
+func (w *OmitLogger) Log(ctx context.Context, level Level, args ...interface{}) {
+	w.l.Log(ctx, level, args...)
+}
+
+func (w *OmitLogger) Logf(ctx context.Context, level Level, msg string, args ...interface{}) {
+	w.l.Logf(ctx, level, msg, args...)
+}
+
+func (w *OmitLogger) String() string {
+	return w.l.String()
+}
+
+type OmitWrapper struct{}
+
+func NewOmitWrapper() Wrapper {
+	return &OmitWrapper{}
+}
+
+func getArgs(args []interface{}) []interface{} {
+	nargs := make([]interface{}, 0, len(args))
+	var err error
+	for _, arg := range args {
+		val := reflect.ValueOf(arg)
+		switch val.Kind() {
+		case reflect.Ptr:
+			val = val.Elem()
+		}
+		narg := arg
+		if val.Kind() == reflect.Struct {
+			if narg, err = rutil.Zero(arg); err == nil {
+				rutil.CopyDefaults(narg, arg)
+				if flds, ferr := rutil.StructFields(narg); ferr == nil {
+					for _, fld := range flds {
+						if tv, ok := fld.Field.Tag.Lookup("logger"); ok && tv == "omit" {
+							fld.Value.Set(reflect.Zero(fld.Value.Type()))
+						}
+					}
+				}
+			}
+		}
+		nargs = append(nargs, narg)
+	}
+	return nargs
+}
+
+func (w *OmitWrapper) Log(fn LogFunc) LogFunc {
+	return func(ctx context.Context, level Level, args ...interface{}) {
+		fn(ctx, level, getArgs(args)...)
+	}
+}
+
+func (w *OmitWrapper) Logf(fn LogfFunc) LogfFunc {
+	return func(ctx context.Context, level Level, msg string, args ...interface{}) {
+		fn(ctx, level, msg, getArgs(args)...)
+	}
+}

logger/wrapper/wrapper.go

@@ -3,6 +3,7 @@ package wrapper
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/unistack-org/micro/v3/client"
 	"github.com/unistack-org/micro/v3/logger"
@@ -57,6 +58,8 @@ var (
 		}
 		return labels
 	}
+
+	DefaultSkipEndpoints = []string{"Meter.Metrics"}
 )
 
 type lWrapper struct {
@@ -67,21 +70,23 @@ type lWrapper struct {
 	opts             Options
 }
 
-type ClientCallObserver func(context.Context, client.Request, interface{}, []client.CallOption, error) []string
-type ClientStreamObserver func(context.Context, client.Request, []client.CallOption, client.Stream, error) []string
-type ClientPublishObserver func(context.Context, client.Message, []client.PublishOption, error) []string
-type ClientCallFuncObserver func(context.Context, string, client.Request, interface{}, client.CallOptions, error) []string
-type ServerHandlerObserver func(context.Context, server.Request, interface{}, error) []string
-type ServerSubscriberObserver func(context.Context, server.Message, error) []string
+type (
+	ClientCallObserver       func(context.Context, client.Request, interface{}, []client.CallOption, error) []string
+	ClientStreamObserver     func(context.Context, client.Request, []client.CallOption, client.Stream, error) []string
+	ClientPublishObserver    func(context.Context, client.Message, []client.PublishOption, error) []string
+	ClientCallFuncObserver   func(context.Context, string, client.Request, interface{}, client.CallOptions, error) []string
+	ServerHandlerObserver    func(context.Context, server.Request, interface{}, error) []string
+	ServerSubscriberObserver func(context.Context, server.Message, error) []string
+)
 
 // Options struct for wrapper
 type Options struct {
 	// Logger that used for log
 	Logger logger.Logger
-	// Level for logger
-	Level logger.Level
-	// Enabled flag
-	Enabled bool
+	// ServerHandlerObservers funcs
+	ServerHandlerObservers []ServerHandlerObserver
+	// ServerSubscriberObservers funcs
+	ServerSubscriberObservers []ServerSubscriberObserver
 	// ClientCallObservers funcs
 	ClientCallObservers []ClientCallObserver
 	// ClientStreamObservers funcs
@@ -90,10 +95,12 @@ type Options struct {
 	ClientPublishObservers []ClientPublishObserver
 	// ClientCallFuncObservers funcs
 	ClientCallFuncObservers []ClientCallFuncObserver
-	// ServerHandlerObservers funcs
-	ServerHandlerObservers []ServerHandlerObserver
-	// ServerSubscriberObservers funcs
-	ServerSubscriberObservers []ServerSubscriberObserver
+	// SkipEndpoints
+	SkipEndpoints []string
+	// Level for logger
+	Level logger.Level
+	// Enabled flag
+	Enabled bool
 }
 
 // Option func signature
@@ -110,6 +117,7 @@ func NewOptions(opts ...Option) Options {
 		ClientCallFuncObservers:   []ClientCallFuncObserver{DefaultClientCallFuncObserver},
 		ServerHandlerObservers:    []ServerHandlerObserver{DefaultServerHandlerObserver},
 		ServerSubscriberObservers: []ServerSubscriberObserver{DefaultServerSubscriberObserver},
+		SkipEndpoints:             DefaultSkipEndpoints,
 	}
 
 	for _, o := range opts {
@@ -182,9 +190,23 @@ func WithServerSubscriberObservers(ob ...ServerSubscriberObserver) Option {
 	}
 }
 
+// SkipEndpoins
+func SkipEndpoints(eps ...string) Option {
+	return func(o *Options) {
+		o.SkipEndpoints = append(o.SkipEndpoints, eps...)
+	}
+}
+
 func (l *lWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
 	err := l.Client.Call(ctx, req, rsp, opts...)
 
+	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return err
 	}
@@ -193,7 +215,7 @@ func (l *lWrapper) Call(ctx context.Context, req client.Request, rsp interface{}
 	for _, o := range l.opts.ClientCallObservers {
 		labels = append(labels, o(ctx, req, rsp, opts, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}
@@ -205,6 +227,13 @@ func (l *lWrapper) Call(ctx context.Context, req client.Request, rsp interface{}
 func (l *lWrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
 	stream, err := l.Client.Stream(ctx, req, opts...)
 
+	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return stream, err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return stream, err
 	}
@@ -213,7 +242,7 @@ func (l *lWrapper) Stream(ctx context.Context, req client.Request, opts ...clien
 	for _, o := range l.opts.ClientStreamObservers {
 		labels = append(labels, o(ctx, req, opts, stream, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}
@@ -225,6 +254,13 @@ func (l *lWrapper) Stream(ctx context.Context, req client.Request, opts ...clien
 func (l *lWrapper) Publish(ctx context.Context, msg client.Message, opts ...client.PublishOption) error {
 	err := l.Client.Publish(ctx, msg, opts...)
 
+	endpoint := msg.Topic()
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return err
 	}
@@ -233,7 +269,7 @@ func (l *lWrapper) Publish(ctx context.Context, msg client.Message, opts ...clie
 	for _, o := range l.opts.ClientPublishObservers {
 		labels = append(labels, o(ctx, msg, opts, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}
@@ -245,6 +281,13 @@ func (l *lWrapper) Publish(ctx context.Context, msg client.Message, opts ...clie
 func (l *lWrapper) ServerHandler(ctx context.Context, req server.Request, rsp interface{}) error {
 	err := l.serverHandler(ctx, req, rsp)
 
+	endpoint := req.Endpoint()
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return err
 	}
@@ -253,7 +296,7 @@ func (l *lWrapper) ServerHandler(ctx context.Context, req server.Request, rsp in
 	for _, o := range l.opts.ServerHandlerObservers {
 		labels = append(labels, o(ctx, req, rsp, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}
@@ -265,6 +308,13 @@ func (l *lWrapper) ServerHandler(ctx context.Context, req server.Request, rsp in
 func (l *lWrapper) ServerSubscriber(ctx context.Context, msg server.Message) error {
 	err := l.serverSubscriber(ctx, msg)
 
+	endpoint := msg.Topic()
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return err
 	}
@@ -273,7 +323,7 @@ func (l *lWrapper) ServerSubscriber(ctx context.Context, msg server.Message) err
 	for _, o := range l.opts.ServerSubscriberObservers {
 		labels = append(labels, o(ctx, msg, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}
@@ -309,6 +359,13 @@ func NewClientCallWrapper(opts ...Option) client.CallWrapper {
 func (l *lWrapper) ClientCallFunc(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
 	err := l.clientCallFunc(ctx, addr, req, rsp, opts)
 
+	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range l.opts.SkipEndpoints {
+		if ep == endpoint {
+			return err
+		}
+	}
+
 	if !l.opts.Enabled {
 		return err
 	}
@@ -317,7 +374,7 @@ func (l *lWrapper) ClientCallFunc(ctx context.Context, addr string, req client.R
 	for _, o := range l.opts.ClientCallFuncObservers {
 		labels = append(labels, o(ctx, addr, req, rsp, opts, err)...)
 	}
-	fields := make(map[string]interface{}, int(len(labels)/2))
+	fields := make(map[string]interface{}, len(labels)/2)
 	for i := 0; i < len(labels); i += 2 {
 		fields[labels[i]] = labels[i+1]
 	}

metadata/context.go

@@ -5,9 +5,11 @@ import (
 	"context"
 )
 
-type mdIncomingKey struct{}
-type mdOutgoingKey struct{}
-type mdKey struct{}
+type (
+	mdIncomingKey struct{}
+	mdOutgoingKey struct{}
+	mdKey         struct{}
+)
 
 // FromIncomingContext returns metadata from incoming ctx
 // returned metadata shoud not be modified or race condition happens

metadata/metadata.go

@@ -7,8 +7,18 @@ import (
 )
 
 var (
-	// HeaderPrefix for all headers passed
-	HeaderPrefix = "Micro-"
+	// HeaderTopic is the header name that contains topic name
+	HeaderTopic = "Micro-Topic"
+	// HeaderContentType specifies content type of message
+	HeaderContentType = "Content-Type"
+	// HeaderEndpoint specifies endpoint in service
+	HeaderEndpoint = "Micro-Endpoint"
+	// HeaderService specifies service
+	HeaderService = "Micro-Service"
+	// HeaderTimeout specifies timeout of operation
+	HeaderTimeout = "Micro-Timeout"
+	// HeaderAuthorization specifies Authorization header
+	HeaderAuthorization = "Authorization"
 )
 
 // Metadata is our way of representing request headers internally.
@@ -20,10 +30,8 @@ type rawMetadata struct {
 	md Metadata
 }
 
-var (
-	// defaultMetadataSize used when need to init new Metadata
-	defaultMetadataSize = 2
-)
+// defaultMetadataSize used when need to init new Metadata
+var defaultMetadataSize = 2
 
 // Iterator used to iterate over metadata with order
 type Iterator struct {

metadata/metadata_test.go

@@ -76,7 +76,7 @@ func TestIterator(t *testing.T) {
 	var k, v string
 
 	for iter.Next(&k, &v) {
-		//fmt.Printf("k: %s, v: %s\n", k, v)
+		// fmt.Printf("k: %s, v: %s\n", k, v)
 	}
 }
 
@@ -102,7 +102,6 @@ func TestMedataCanonicalKey(t *testing.T) {
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
 	}
-
 }
 
 func TestMetadataSet(t *testing.T) {
@@ -130,7 +129,6 @@ func TestMetadataDelete(t *testing.T) {
 	if ok {
 		t.Fatal("key Baz not deleted")
 	}
-
 }
 
 func TestNilContext(t *testing.T) {

meter/handler/handler.go

@@ -1,33 +1,64 @@
-package pb
+package handler
 
 import (
 	"bytes"
 	"context"
 
 	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/errors"
 	"github.com/unistack-org/micro/v3/meter"
 )
 
-var (
-	// guard to fail early
-	_ MeterServer = &handler{}
-)
+// guard to fail early
+var _ MeterServer = &Handler{}
 
-type Empty struct{}
-
-type handler struct {
-	meter meter.Meter
-	opts  []meter.Option
+type Handler struct {
+	opts Options
 }
 
-func NewHandler(meter meter.Meter, opts ...meter.Option) *handler {
-	return &handler{meter: meter, opts: opts}
+type Option func(*Options)
+
+type Options struct {
+	Meter        meter.Meter
+	Name         string
+	MeterOptions []meter.Option
 }
 
-func (h *handler) Metrics(ctx context.Context, req *Empty, rsp *codec.Frame) error {
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+func Name(name string) Option {
+	return func(o *Options) {
+		o.Name = name
+	}
+}
+
+func MeterOptions(opts ...meter.Option) Option {
+	return func(o *Options) {
+		o.MeterOptions = append(o.MeterOptions, opts...)
+	}
+}
+
+func NewOptions(opts ...Option) Options {
+	options := Options{Meter: meter.DefaultMeter}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+func NewHandler(opts ...Option) *Handler {
+	options := NewOptions(opts...)
+	return &Handler{opts: options}
+}
+
+func (h *Handler) Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
 	buf := bytes.NewBuffer(nil)
-	if err := h.meter.Write(buf, h.opts...); err != nil {
-		return err
+	if err := h.opts.Meter.Write(buf, h.opts.MeterOptions...); err != nil {
+		return errors.InternalServerError(h.opts.Name, "%v", err)
 	}
 
 	rsp.Data = buf.Bytes()

meter/handler/handler.proto

@@ -1,14 +1,14 @@
 syntax = "proto3";
 
-package meter;
-option go_package = "github.com/unistack-org/micro/v3/meter/handler;pb";
+package micro.meter.handler;
+option go_package = "github.com/unistack-org/micro/v3/meter/handler;handler";
 
 import "api/annotations.proto";
 import "openapiv2/annotations.proto";
 import "codec/frame.proto";
 
 service Meter {
-	rpc Metrics(Empty) returns (micro.codec.Frame) {
+	rpc Metrics(micro.codec.Frame) returns (micro.codec.Frame) {
 		option (micro.openapiv2.openapiv2_operation) = {
       operation_id: "Metrics";
         responses: {
@@ -17,7 +17,7 @@ service Meter {
             description: "Error response";
             schema: {
               json_schema: {
-                ref: "Empty";
+                ref: "micro.codec.Frame";
               }
             }
           }
@@ -26,5 +26,3 @@ service Meter {
 		option (micro.api.http) = { get: "/metrics"; };
   };
 };
-
-message Empty{};

meter/handler/handler_micro.pb.go

@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-micro
 // source: handler.proto
-package pb
+package handler
 
 import (
 	context "context"
@@ -20,5 +20,5 @@ func NewMeterEndpoints() []*api.Endpoint {
 }
 
 type MeterServer interface {
-	Metrics(ctx context.Context, req *Empty, rsp *codec.Frame) error
+	Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
 }

meter/handler/handler_micro_http.pb.go

@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-micro
 // source: handler.proto
-package pb
+package handler
 
 import (
 	context "context"
@@ -13,20 +13,21 @@ type meterServer struct {
 	MeterServer
 }
 
-func (h *meterServer) Metrics(ctx context.Context, req *Empty, rsp *codec.Frame) error {
+func (h *meterServer) Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
 	return h.MeterServer.Metrics(ctx, req, rsp)
 }
 
 func RegisterMeterServer(s server.Server, sh MeterServer, opts ...server.HandlerOption) error {
 	type meter interface {
-		Metrics(ctx context.Context, req *Empty, rsp *codec.Frame) error
+		Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
 	}
 	type Meter struct {
 		meter
 	}
 	h := &meterServer{sh}
+	var nopts []server.HandlerOption
 	for _, endpoint := range NewMeterEndpoints() {
-		opts = append(opts, api.WithEndpoint(endpoint))
+		nopts = append(nopts, api.WithEndpoint(endpoint))
 	}
-	return s.Handle(s.NewHandler(&Meter{h}, opts...))
+	return s.Handle(s.NewHandler(&Meter{h}, append(nopts, opts...)...))
 }

meter/meter.go

@@ -3,8 +3,9 @@ package meter
 
 import (
 	"io"
-	"reflect"
 	"sort"
+	"strconv"
+	"strings"
 	"time"
 )
 
@@ -29,13 +30,13 @@ var (
 type Meter interface {
 	Name() string
 	Init(opts ...Option) error
-	Counter(name string, opts ...Option) Counter
-	FloatCounter(name string, opts ...Option) FloatCounter
-	Gauge(name string, fn func() float64, opts ...Option) Gauge
+	Counter(name string, labels ...string) Counter
+	FloatCounter(name string, labels ...string) FloatCounter
+	Gauge(name string, fn func() float64, labels ...string) Gauge
 	Set(opts ...Option) Meter
-	Histogram(name string, opts ...Option) Histogram
-	Summary(name string, opts ...Option) Summary
-	SummaryExt(name string, window time.Duration, quantiles []float64, opts ...Option) Summary
+	Histogram(name string, labels ...string) Histogram
+	Summary(name string, labels ...string) Summary
+	SummaryExt(name string, window time.Duration, quantiles []float64, labels ...string) Summary
 	Write(w io.Writer, opts ...Option) error
 	Options() Options
 	String() string
@@ -77,36 +78,62 @@ type Summary interface {
 	UpdateDuration(time.Time)
 }
 
+// sort labels alphabeticaly by label name
 type byKey []string
 
 func (k byKey) Len() int           { return len(k) / 2 }
 func (k byKey) Less(i, j int) bool { return k[i*2] < k[j*2] }
 func (k byKey) Swap(i, j int) {
-	k[i*2], k[i*2+1], k[j*2], k[j*2+1] = k[j*2], k[j*2+1], k[i*2], k[i*2+1]
+	k[i*2], k[j*2] = k[j*2], k[i*2]
+	k[i*2+1], k[j*2+1] = k[j*2+1], k[i*2+1]
 }
 
-func Sort(slice *[]string) {
-	bk := byKey(*slice)
-	if bk.Len() <= 1 {
-		return
+// BuildLables used to sort labels and delete duplicates.
+// Last value wins in case of duplicate label keys.
+func BuildLabels(labels ...string) []string {
+	if len(labels)%2 == 1 {
+		labels = labels[:len(labels)-1]
 	}
-	sort.Sort(bk)
-	v := reflect.ValueOf(slice).Elem()
-	cnt := 0
-	key := 0
-	val := 1
-	for key < v.Len() {
-		if len(bk) > key+2 && bk[key] == bk[key+2] {
-			key += 2
-			val += 2
-			continue
-		}
-		v.Index(cnt).Set(v.Index(key))
-		cnt++
-		v.Index(cnt).Set(v.Index(val))
-		cnt++
-		key += 2
-		val += 2
-	}
-	v.SetLen(cnt)
+	sort.Sort(byKey(labels))
+	return labels
+}
+
+// BuildName used to combine metric with labels.
+// If labels count is odd, drop last element
+func BuildName(name string, labels ...string) string {
+	if len(labels)%2 == 1 {
+		labels = labels[:len(labels)-1]
+	}
+
+	if len(labels) > 2 {
+		sort.Sort(byKey(labels))
+
+		idx := 0
+		for {
+			if labels[idx] == labels[idx+2] {
+				copy(labels[idx:], labels[idx+2:])
+				labels = labels[:len(labels)-2]
+			} else {
+				idx += 2
+			}
+			if idx+2 >= len(labels) {
+				break
+			}
+		}
+	}
+
+	var b strings.Builder
+	_, _ = b.WriteString(name)
+	_, _ = b.WriteRune('{')
+	for idx := 0; idx < len(labels); idx += 2 {
+		if idx > 0 {
+			_, _ = b.WriteRune(',')
+		}
+		_, _ = b.WriteString(labels[idx])
+		_, _ = b.WriteString(`=`)
+		_, _ = b.WriteString(strconv.Quote(labels[idx+1]))
+	}
+	_, _ = b.WriteRune('}')
+
+	return b.String()
 }

meter/meter_test.go

@@ -10,15 +10,61 @@ func TestNoopMeter(t *testing.T) {
 		t.Fatalf("invalid options parsing: %v", m.Options())
 	}
 
-	cnt := m.Counter("counter", Labels("server", "noop"))
+	cnt := m.Counter("counter", "server", "noop")
 	cnt.Inc()
 }
 
-func TestLabelsSort(t *testing.T) {
-	ls := []string{"server", "http", "register", "mdns", "broker", "broker1", "broker", "broker2", "server", "tcp"}
-	Sort(&ls)
+func testEq(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
 
-	if ls[0] != "broker" || ls[1] != "broker2" {
-		t.Fatalf("sort error: %v", ls)
+func TestBuildLabels(t *testing.T) {
+	type testData struct {
+		src []string
+		dst []string
+	}
+
+	data := []testData{
+		testData{
+			src: []string{"zerolabel", "value3", "firstlabel", "value2"},
+			dst: []string{"firstlabel", "value2", "zerolabel", "value3"},
+		},
+	}
+
+	for _, d := range data {
+		if !testEq(d.dst, BuildLabels(d.src...)) {
+			t.Fatalf("slices not properly sorted: %v %v", d.dst, d.src)
+		}
+	}
+}
+
+func TestBuildName(t *testing.T) {
+	data := map[string][]string{
+		`my_metric{firstlabel="value2",zerolabel="value3"}`: []string{
+			"my_metric",
+			"zerolabel", "value3", "firstlabel", "value2",
+		},
+		`my_metric{broker="broker2",register="mdns",server="tcp"}`: []string{
+			"my_metric",
+			"broker", "broker1", "broker", "broker2", "server", "http", "server", "tcp", "register", "mdns",
+		},
+		`my_metric{aaa="aaa"}`: []string{
+			"my_metric",
+			"aaa", "aaa",
+		},
+	}
+
+	for e, d := range data {
+		if x := BuildName(d[0], d[1:]...); x != e {
+			t.Fatalf("expect: %s, result: %s", e, x)
+		}
 	}
 }

meter/noop.go

@@ -28,57 +28,33 @@ func (r *noopMeter) Init(opts ...Option) error {
 }
 
 // Counter implements the Meter interface
-func (r *noopMeter) Counter(name string, opts ...Option) Counter {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopCounter{labels: options.Labels}
+func (r *noopMeter) Counter(name string, labels ...string) Counter {
+	return &noopCounter{labels: labels}
 }
 
 // FloatCounter implements the Meter interface
-func (r *noopMeter) FloatCounter(name string, opts ...Option) FloatCounter {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopFloatCounter{labels: options.Labels}
+func (r *noopMeter) FloatCounter(name string, labels ...string) FloatCounter {
+	return &noopFloatCounter{labels: labels}
 }
 
 // Gauge implements the Meter interface
-func (r *noopMeter) Gauge(name string, f func() float64, opts ...Option) Gauge {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopGauge{labels: options.Labels}
+func (r *noopMeter) Gauge(name string, f func() float64, labels ...string) Gauge {
+	return &noopGauge{labels: labels}
 }
 
 // Summary implements the Meter interface
-func (r *noopMeter) Summary(name string, opts ...Option) Summary {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopSummary{labels: options.Labels}
+func (r *noopMeter) Summary(name string, labels ...string) Summary {
+	return &noopSummary{labels: labels}
 }
 
 // SummaryExt implements the Meter interface
-func (r *noopMeter) SummaryExt(name string, window time.Duration, quantiles []float64, opts ...Option) Summary {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopSummary{labels: options.Labels}
+func (r *noopMeter) SummaryExt(name string, window time.Duration, quantiles []float64, labels ...string) Summary {
+	return &noopSummary{labels: labels}
 }
 
 // Histogram implements the Meter interface
-func (r *noopMeter) Histogram(name string, opts ...Option) Histogram {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopHistogram{labels: options.Labels}
+func (r *noopMeter) Histogram(name string, labels ...string) Histogram {
+	return &noopHistogram{labels: labels}
 }
 
 // Set implements the Meter interface
@@ -111,11 +87,9 @@ type noopCounter struct {
 }
 
 func (r *noopCounter) Add(int) {
-
 }
 
 func (r *noopCounter) Dec() {
-
 }
 
 func (r *noopCounter) Get() uint64 {
@@ -123,11 +97,9 @@ func (r *noopCounter) Get() uint64 {
 }
 
 func (r *noopCounter) Inc() {
-
 }
 
 func (r *noopCounter) Set(uint64) {
-
 }
 
 type noopFloatCounter struct {
@@ -135,7 +107,6 @@ type noopFloatCounter struct {
 }
 
 func (r *noopFloatCounter) Add(float64) {
-
 }
 
 func (r *noopFloatCounter) Get() float64 {
@@ -143,11 +114,9 @@ func (r *noopFloatCounter) Get() float64 {
 }
 
 func (r *noopFloatCounter) Set(float64) {
-
 }
 
 func (r *noopFloatCounter) Sub(float64) {
-
 }
 
 type noopGauge struct {
@@ -163,11 +132,9 @@ type noopSummary struct {
 }
 
 func (r *noopSummary) Update(float64) {
-
 }
 
 func (r *noopSummary) UpdateDuration(time.Time) {
-
 }
 
 type noopHistogram struct {
@@ -175,15 +142,12 @@ type noopHistogram struct {
 }
 
 func (r *noopHistogram) Reset() {
-
 }
 
 func (r *noopHistogram) Update(float64) {
-
 }
 
 func (r *noopHistogram) UpdateDuration(time.Time) {
-
 }
 
-//func (r *noopHistogram) VisitNonZeroBuckets(f func(vmrange string, count uint64)) {}
+// func (r *noopHistogram) VisitNonZeroBuckets(f func(vmrange string, count uint64)) {}

meter/options.go

@@ -90,7 +90,7 @@ func Logger(l logger.Logger) Option {
 
 func Labels(ls ...string) Option {
 	return func(o *Options) {
-		o.Labels = ls
+		o.Labels = append(o.Labels, ls...)
 	}
 }
 

meter/wrapper/wrapper.go

@@ -11,36 +11,48 @@ import (
 )
 
 var (
-	ClientRequestDurationSeconds        = "client_request_duration_seconds"
-	ClientRequestLatencyMicroseconds    = "client_request_latency_microseconds"
-	ClientRequestTotal                  = "client_request_total"
-	ServerRequestDurationSeconds        = "server_request_duration_seconds"
-	ServerRequestLatencyMicroseconds    = "server_request_latency_microseconds"
-	ServerRequestTotal                  = "server_request_total"
-	PublishMessageDurationSeconds       = "publish_message_duration_seconds"
-	PublishMessageLatencyMicroseconds   = "publish_message_latency_microseconds"
-	PublishMessageTotal                 = "publish_message_total"
+	ClientRequestDurationSeconds     = "client_request_duration_seconds"
+	ClientRequestLatencyMicroseconds = "client_request_latency_microseconds"
+	ClientRequestTotal               = "client_request_total"
+	ClientRequestInflight            = "client_request_inflight"
+
+	ServerRequestDurationSeconds     = "server_request_duration_seconds"
+	ServerRequestLatencyMicroseconds = "server_request_latency_microseconds"
+	ServerRequestTotal               = "server_request_total"
+	ServerRequestInflight            = "server_request_inflight"
+
+	PublishMessageDurationSeconds     = "publish_message_duration_seconds"
+	PublishMessageLatencyMicroseconds = "publish_message_latency_microseconds"
+	PublishMessageTotal               = "publish_message_total"
+	PublishMessageInflight            = "publish_message_inflight"
+
 	SubscribeMessageDurationSeconds     = "subscribe_message_duration_seconds"
 	SubscribeMessageLatencyMicroseconds = "subscribe_message_latency_microseconds"
 	SubscribeMessageTotal               = "subscribe_message_total"
+	SubscribeMessageInflight            = "subscribe_message_inflight"
 
 	labelSuccess  = "success"
 	labelFailure  = "failure"
 	labelStatus   = "status"
 	labelEndpoint = "endpoint"
+
+	// DefaultSkipEndpoints contains list of endpoints that not evaluted by wrapper
+	DefaultSkipEndpoints = []string{"Meter.Metrics"}
 )
 
 type Options struct {
-	Meter meter.Meter
-	lopts []meter.Option
+	Meter         meter.Meter
+	lopts         []meter.Option
+	SkipEndpoints []string
 }
 
 type Option func(*Options)
 
 func NewOptions(opts ...Option) Options {
 	options := Options{
-		Meter: meter.DefaultMeter,
-		lopts: make([]meter.Option, 0, 5),
+		Meter:         meter.DefaultMeter,
+		lopts:         make([]meter.Option, 0, 5),
+		SkipEndpoints: DefaultSkipEndpoints,
 	}
 	for _, o := range opts {
 		o(&options)
@@ -72,6 +84,12 @@ func Meter(m meter.Meter) Option {
 	}
 }
 
+func SkipEndoints(eps ...string) Option {
+	return func(o *Options) {
+		o.SkipEndpoints = append(o.SkipEndpoints, eps...)
+	}
+}
+
 type wrapper struct {
 	client.Client
 	callFunc client.CallFunc
@@ -100,69 +118,90 @@ func NewCallWrapper(opts ...Option) client.CallWrapper {
 
 func (w *wrapper) CallFunc(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
 	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range w.opts.SkipEndpoints {
+		if ep == endpoint {
+			return w.callFunc(ctx, addr, req, rsp, opts)
+		}
+	}
 
+	labels := make([]string, 0, 4)
+	labels = append(labels, labelEndpoint, endpoint)
+
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Inc()
 	ts := time.Now()
 	err := w.callFunc(ctx, addr, req, rsp, opts)
 	te := time.Since(ts)
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Dec()
 
-	lopts := w.opts.lopts
-	lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-	w.opts.Meter.Histogram(ClientRequestDurationSeconds, lopts...).Update(float64(te.Seconds()))
+	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, labels...).Update(te.Seconds())
+	w.opts.Meter.Histogram(ClientRequestDurationSeconds, labels...).Update(te.Seconds())
 
 	if err == nil {
-		lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+		labels = append(labels, labelStatus, labelSuccess)
 	} else {
-		lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+		labels = append(labels, labelStatus, labelFailure)
 	}
-	w.opts.Meter.Counter(ClientRequestTotal, lopts...).Inc()
+	w.opts.Meter.Counter(ClientRequestTotal, labels...).Inc()
 
 	return err
 }
 
 func (w *wrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
 	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range w.opts.SkipEndpoints {
+		if ep == endpoint {
+			return w.Client.Call(ctx, req, rsp, opts...)
+		}
+	}
 
+	labels := make([]string, 0, 4)
+	labels = append(labels, labelEndpoint, endpoint)
+
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Inc()
 	ts := time.Now()
 	err := w.Client.Call(ctx, req, rsp, opts...)
 	te := time.Since(ts)
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Dec()
 
-	lopts := w.opts.lopts
-	lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-	w.opts.Meter.Histogram(ClientRequestDurationSeconds, lopts...).Update(float64(te.Seconds()))
+	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, labels...).Update(te.Seconds())
+	w.opts.Meter.Histogram(ClientRequestDurationSeconds, labels...).Update(te.Seconds())
 
 	if err == nil {
-		lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+		labels = append(labels, labelStatus, labelSuccess)
 	} else {
-		lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+		labels = append(labels, labelStatus, labelFailure)
 	}
-	w.opts.Meter.Counter(ClientRequestTotal, lopts...).Inc()
+	w.opts.Meter.Counter(ClientRequestTotal, labels...).Inc()
 
 	return err
 }
 
 func (w *wrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
 	endpoint := fmt.Sprintf("%s.%s", req.Service(), req.Endpoint())
+	for _, ep := range w.opts.SkipEndpoints {
+		if ep == endpoint {
+			return w.Client.Stream(ctx, req, opts...)
+		}
+	}
 
+	labels := make([]string, 0, 4)
+	labels = append(labels, labelEndpoint, endpoint)
+
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Inc()
 	ts := time.Now()
 	stream, err := w.Client.Stream(ctx, req, opts...)
 	te := time.Since(ts)
+	w.opts.Meter.Counter(ClientRequestInflight, labels...).Dec()
 
-	lopts := w.opts.lopts
-	lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-	w.opts.Meter.Histogram(ClientRequestDurationSeconds, lopts...).Update(float64(te.Seconds()))
+	w.opts.Meter.Summary(ClientRequestLatencyMicroseconds, labels...).Update(te.Seconds())
+	w.opts.Meter.Histogram(ClientRequestDurationSeconds, labels...).Update(te.Seconds())
 
 	if err == nil {
-		lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+		labels = append(labels, labelStatus, labelSuccess)
 	} else {
-		lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+		labels = append(labels, labelStatus, labelFailure)
 	}
-	w.opts.Meter.Counter(ClientRequestTotal, lopts...).Inc()
+	w.opts.Meter.Counter(ClientRequestTotal, labels...).Inc()
 
 	return stream, err
 }
@@ -170,22 +209,24 @@ 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 {
 	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()
 
-	lopts := w.opts.lopts
-	lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-	w.opts.Meter.Summary(PublishMessageLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-	w.opts.Meter.Histogram(PublishMessageDurationSeconds, lopts...).Update(float64(te.Seconds()))
+	w.opts.Meter.Summary(PublishMessageLatencyMicroseconds, labels...).Update(te.Seconds())
+	w.opts.Meter.Histogram(PublishMessageDurationSeconds, labels...).Update(te.Seconds())
 
 	if err == nil {
-		lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+		labels = append(labels, labelStatus, labelSuccess)
 	} else {
-		lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+		labels = append(labels, labelStatus, labelFailure)
 	}
-	w.opts.Meter.Counter(PublishMessageTotal, lopts...).Inc()
+	w.opts.Meter.Counter(PublishMessageTotal, labels...).Inc()
 
 	return err
 }
@@ -200,23 +241,30 @@ func NewHandlerWrapper(opts ...Option) server.HandlerWrapper {
 func (w *wrapper) HandlerFunc(fn server.HandlerFunc) server.HandlerFunc {
 	return func(ctx context.Context, req server.Request, rsp interface{}) error {
 		endpoint := req.Endpoint()
+		for _, ep := range w.opts.SkipEndpoints {
+			if ep == endpoint {
+				return fn(ctx, req, rsp)
+			}
+		}
 
+		labels := make([]string, 0, 4)
+		labels = append(labels, labelEndpoint, endpoint)
+
+		w.opts.Meter.Counter(ServerRequestInflight, labels...).Inc()
 		ts := time.Now()
 		err := fn(ctx, req, rsp)
 		te := time.Since(ts)
+		w.opts.Meter.Counter(ServerRequestInflight, labels...).Dec()
 
-		lopts := w.opts.lopts
-		lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-		w.opts.Meter.Summary(ServerRequestLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-		w.opts.Meter.Histogram(ServerRequestDurationSeconds, lopts...).Update(float64(te.Seconds()))
+		w.opts.Meter.Summary(ServerRequestLatencyMicroseconds, labels...).Update(te.Seconds())
+		w.opts.Meter.Histogram(ServerRequestDurationSeconds, labels...).Update(te.Seconds())
 
 		if err == nil {
-			lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+			labels = append(labels, labelStatus, labelSuccess)
 		} else {
-			lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+			labels = append(labels, labelStatus, labelFailure)
 		}
-		w.opts.Meter.Counter(ServerRequestTotal, lopts...).Inc()
+		w.opts.Meter.Counter(ServerRequestTotal, labels...).Inc()
 
 		return err
 	}
@@ -233,22 +281,24 @@ 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()
 
-		lopts := w.opts.lopts
-		lopts = append(lopts, meter.Labels(labelEndpoint, endpoint))
-
-		w.opts.Meter.Summary(SubscribeMessageLatencyMicroseconds, lopts...).Update(float64(te.Seconds()))
-		w.opts.Meter.Histogram(SubscribeMessageDurationSeconds, lopts...).Update(float64(te.Seconds()))
+		w.opts.Meter.Summary(SubscribeMessageLatencyMicroseconds, labels...).Update(te.Seconds())
+		w.opts.Meter.Histogram(SubscribeMessageDurationSeconds, labels...).Update(te.Seconds())
 
 		if err == nil {
-			lopts = append(lopts, meter.Labels(labelStatus, labelSuccess))
+			labels = append(labels, labelStatus, labelSuccess)
 		} else {
-			lopts = append(lopts, meter.Labels(labelStatus, labelFailure))
+			labels = append(labels, labelStatus, labelFailure)
 		}
-		w.opts.Meter.Counter(SubscribeMessageTotal, lopts...).Inc()
+		w.opts.Meter.Counter(SubscribeMessageTotal, labels...).Inc()
 
 		return err
 	}

network/transport/memory.go

@@ -31,18 +31,18 @@ type memoryClient struct {
 }
 
 type memoryListener struct {
-	topts Options
-	ctx   context.Context
 	lopts ListenOptions
+	ctx   context.Context
 	exit  chan bool
 	conn  chan *memorySocket
 	addr  string
+	topts Options
 	sync.RWMutex
 }
 
 type memoryTransport struct {
-	opts      Options
 	listeners map[string]*memoryListener
+	opts      Options
 	sync.RWMutex
 }
 

network/transport/memory_test.go

@@ -27,9 +27,9 @@ func TestMemoryTransport(t *testing.T) {
 				if len(os.Getenv("INTEGRATION_TESTS")) == 0 {
 					t.Logf("Server Received %s", string(m.Body))
 				}
-				if err := sock.Send(&Message{
+				if cerr := sock.Send(&Message{
 					Body: []byte(`pong`),
-				}); err != nil {
+				}); cerr != nil {
 					return
 				}
 			}
@@ -60,7 +60,6 @@ func TestMemoryTransport(t *testing.T) {
 			t.Logf("Client Received %s", string(m.Body))
 		}
 	}
-
 }
 
 func TestListener(t *testing.T) {

network/tunnel/broker/broker.go

@@ -12,26 +12,37 @@ import (
 )
 
 type tunBroker struct {
-	opts   broker.Options
 	tunnel tunnel.Tunnel
+	opts   broker.Options
 }
 
 type tunSubscriber struct {
-	opts     broker.SubscribeOptions
 	listener tunnel.Listener
 	handler  broker.Handler
 	closed   chan bool
 	topic    string
+	opts     broker.SubscribeOptions
+}
+
+type tunBatchSubscriber struct {
+	listener tunnel.Listener
+	handler  broker.BatchHandler
+	closed   chan bool
+	topic    string
+	opts     broker.SubscribeOptions
 }
 
 type tunEvent struct {
 	message *broker.Message
 	topic   string
+	err     error
 }
 
 // used to access tunnel from options context
-type tunnelKey struct{}
-type tunnelAddr struct{}
+type (
+	tunnelKey  struct{}
+	tunnelAddr struct{}
+)
 
 func (t *tunBroker) Init(opts ...broker.Option) error {
 	for _, o := range opts {
@@ -60,6 +71,36 @@ func (t *tunBroker) Disconnect(ctx context.Context) error {
 	return t.tunnel.Close(ctx)
 }
 
+func (t *tunBroker) BatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+	// TODO: this is probably inefficient, we might want to just maintain an open connection
+	// it may be easier to add broadcast to the tunnel
+	topicMap := make(map[string]tunnel.Session)
+
+	var err error
+	for _, msg := range msgs {
+		topic, _ := msg.Header.Get(metadata.HeaderTopic)
+		c, ok := topicMap[topic]
+		if !ok {
+			c, err := t.tunnel.Dial(ctx, topic, tunnel.DialMode(tunnel.Multicast))
+			if err != nil {
+				return err
+			}
+			defer c.Close()
+			topicMap[topic] = c
+		}
+
+		if err = c.Send(&transport.Message{
+			Header: msg.Header,
+			Body:   msg.Body,
+		}); err != nil {
+			//	msg.SetError(err)
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (t *tunBroker) Publish(ctx context.Context, topic string, m *broker.Message, opts ...broker.PublishOption) error {
 	// TODO: this is probably inefficient, we might want to just maintain an open connection
 	// it may be easier to add broadcast to the tunnel
@@ -75,6 +116,26 @@ func (t *tunBroker) Publish(ctx context.Context, topic string, m *broker.Message
 	})
 }
 
+func (t *tunBroker) BatchSubscribe(ctx context.Context, topic string, h broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	l, err := t.tunnel.Listen(ctx, topic, tunnel.ListenMode(tunnel.Multicast))
+	if err != nil {
+		return nil, err
+	}
+
+	tunSub := &tunBatchSubscriber{
+		topic:    topic,
+		handler:  h,
+		opts:     broker.NewSubscribeOptions(opts...),
+		closed:   make(chan bool),
+		listener: l,
+	}
+
+	// start processing
+	go tunSub.run()
+
+	return tunSub, nil
+}
+
 func (t *tunBroker) Subscribe(ctx context.Context, topic string, h broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
 	l, err := t.tunnel.Listen(ctx, topic, tunnel.ListenMode(tunnel.Multicast))
 	if err != nil {
@@ -99,6 +160,49 @@ func (t *tunBroker) String() string {
 	return "tunnel"
 }
 
+func (t *tunBatchSubscriber) run() {
+	for {
+		// accept a new connection
+		c, err := t.listener.Accept()
+		if err != nil {
+			select {
+			case <-t.closed:
+				return
+			default:
+				continue
+			}
+		}
+
+		// receive message
+		m := new(transport.Message)
+		if err := c.Recv(m); err != nil {
+			if logger.V(logger.ErrorLevel) {
+				logger.Error(t.opts.Context, err.Error())
+			}
+			if err = c.Close(); err != nil {
+				if logger.V(logger.ErrorLevel) {
+					logger.Error(t.opts.Context, err.Error())
+				}
+			}
+			continue
+		}
+
+		// close the connection
+		c.Close()
+
+		evts := broker.Events{&tunEvent{
+			topic: t.topic,
+			message: &broker.Message{
+				Header: m.Header,
+				Body:   m.Body,
+			},
+		}}
+		// handle the message
+		go t.handler(evts)
+
+	}
+}
+
 func (t *tunSubscriber) run() {
 	for {
 		// accept a new connection
@@ -140,6 +244,24 @@ func (t *tunSubscriber) run() {
 	}
 }
 
+func (t *tunBatchSubscriber) Options() broker.SubscribeOptions {
+	return t.opts
+}
+
+func (t *tunBatchSubscriber) Topic() string {
+	return t.topic
+}
+
+func (t *tunBatchSubscriber) Unsubscribe(ctx context.Context) error {
+	select {
+	case <-t.closed:
+		return nil
+	default:
+		close(t.closed)
+		return t.listener.Close()
+	}
+}
+
 func (t *tunSubscriber) Options() broker.SubscribeOptions {
 	return t.opts
 }
@@ -171,7 +293,11 @@ func (t *tunEvent) Ack() error {
 }
 
 func (t *tunEvent) Error() error {
-	return nil
+	return t.err
+}
+
+func (t *tunEvent) SetError(err error) {
+	t.err = err
 }
 
 // NewBroker returns new tunnel broker

network/tunnel/options.go

@@ -34,8 +34,8 @@ type Options struct {
 	Token string
 	// Name holds the tunnel name
 	Name string
-	// Id holds the tunnel id
-	Id string
+	// ID holds the tunnel id
+	ID string
 	// Address holds the tunnel address
 	Address string
 	// Nodes holds the tunnel nodes
@@ -68,10 +68,10 @@ type ListenOptions struct {
 	Timeout time.Duration
 }
 
-// Id sets the tunnel id
-func Id(id string) Option {
+// ID sets the tunnel id
+func ID(id string) Option {
 	return func(o *Options) {
-		o.Id = id
+		o.ID = id
 	}
 }
 
@@ -164,7 +164,7 @@ func DialWait(b bool) DialOption {
 // NewOptions returns router default options with filled values
 func NewOptions(opts ...Option) Options {
 	options := Options{
-		Id:      uuid.New().String(),
+		ID:      uuid.New().String(),
 		Address: DefaultAddress,
 		Token:   DefaultToken,
 		Logger:  logger.DefaultLogger,

network/tunnel/transport/transport.go

@@ -10,9 +10,8 @@ import (
 )
 
 type tunTransport struct {
+	tunnel  tunnel.Tunnel
 	options transport.Options
-
-	tunnel tunnel.Tunnel
 }
 
 type tunnelKey struct{}
@@ -88,7 +87,7 @@ func NewTransport(opts ...transport.Option) transport.Transport {
 	}
 
 	// initialise
-	//t.Init(opts...)
+	// t.Init(opts...)
 
 	return t
 }

network/tunnel/tunnel.go

@@ -9,10 +9,8 @@ import (
 	"github.com/unistack-org/micro/v3/network/transport"
 )
 
-var (
-	// DefaultTunnel contains default tunnel implementation
-	DefaultTunnel Tunnel
-)
+// DefaultTunnel contains default tunnel implementation
+var DefaultTunnel Tunnel
 
 const (
 	// Unicast send over one link

options.go

@@ -17,8 +17,6 @@ import (
 	"github.com/unistack-org/micro/v3/server"
 	"github.com/unistack-org/micro/v3/store"
 	"github.com/unistack-org/micro/v3/tracer"
-	//	"github.com/unistack-org/micro/v3/profiler"
-	//	"github.com/unistack-org/micro/v3/runtime"
 )
 
 // Options for micro service
@@ -78,8 +76,8 @@ func NewOptions(opts ...Option) Options {
 		Meters:    []meter.Meter{meter.DefaultMeter},
 		Configs:   []config.Config{config.DefaultConfig},
 		Stores:    []store.Store{store.DefaultStore},
-		//Runtime   runtime.Runtime
-		//Profile   profile.Profile
+		// Runtime   runtime.Runtime
+		// Profile   profile.Profile
 	}
 
 	for _, o := range opts {

profiler/http/http.go

@@ -16,10 +16,8 @@ type httpProfile struct {
 	running bool
 }
 
-var (
-	// DefaultAddress for http profiler
-	DefaultAddress = ":6060"
-)
+// DefaultAddress for http profiler
+var DefaultAddress = ":6060"
 
 // Start the profiler
 func (h *httpProfile) Start() error {

profiler/profile.go

@@ -11,10 +11,8 @@ type Profiler interface {
 	String() string
 }
 
-var (
-	// DefaultProfiler holds the default profiler
-	DefaultProfiler Profiler = NewProfiler()
-)
+// DefaultProfiler holds the default profiler
+var DefaultProfiler Profiler = NewProfiler()
 
 // Options holds the options for profiler
 type Options struct {

proxy/proxy.go

@@ -7,10 +7,8 @@ import (
 	"github.com/unistack-org/micro/v3/server"
 )
 
-var (
-	// DefaultEndpoint holds default proxy address
-	DefaultEndpoint = "localhost:9090"
-)
+// DefaultEndpoint holds default proxy address
+var DefaultEndpoint = "localhost:9090"
 
 // Proxy can be used as a proxy server for micro services
 type Proxy interface {

register/extractor.go

@@ -3,7 +3,6 @@ package register
 import (
 	"fmt"
 	"reflect"
-	"strings"
 	"unicode"
 	"unicode/utf8"
 
@@ -11,12 +10,12 @@ import (
 )
 
 // ExtractValue from reflect.Type from specified depth
-func ExtractValue(v reflect.Type, d int) *Value {
+func ExtractValue(v reflect.Type, d int) string {
 	if d == 3 {
-		return nil
+		return ""
 	}
 	if v == nil {
-		return nil
+		return ""
 	}
 
 	if v.Kind() == reflect.Ptr {
@@ -25,7 +24,7 @@ func ExtractValue(v reflect.Type, d int) *Value {
 
 	// slices and maps don't have a defined name
 	if (v.Kind() == reflect.Slice || v.Kind() == reflect.Map) || len(v.Name()) == 0 {
-		return nil
+		return ""
 	}
 
 	// get the rune character
@@ -33,58 +32,10 @@ func ExtractValue(v reflect.Type, d int) *Value {
 
 	// crude check for is unexported field
 	if unicode.IsLower(a) {
-		return nil
+		return ""
 	}
 
-	arg := &Value{
-		Name: v.Name(),
-		Type: v.Name(),
-	}
-
-	switch v.Kind() {
-	case reflect.Struct:
-		for i := 0; i < v.NumField(); i++ {
-			f := v.Field(i)
-			val := ExtractValue(f.Type, d+1)
-			if val == nil {
-				continue
-			}
-
-			// if we can find a json tag use it
-			if tags := f.Tag.Get("json"); len(tags) > 0 {
-				parts := strings.Split(tags, ",")
-				if parts[0] == "-" || parts[0] == "omitempty" {
-					continue
-				}
-				val.Name = parts[0]
-			}
-
-			// if there's no name default it
-			if len(val.Name) == 0 {
-				val.Name = v.Field(i).Name
-			}
-
-			arg.Values = append(arg.Values, val)
-		}
-	case reflect.Slice:
-		p := v.Elem()
-		if p.Kind() == reflect.Ptr {
-			p = p.Elem()
-		}
-		arg.Type = "[]" + p.Name()
-	case reflect.Map:
-		p := v.Elem()
-		if p.Kind() == reflect.Ptr {
-			p = p.Elem()
-		}
-		key := v.Key()
-		if key.Kind() == reflect.Ptr {
-			key = key.Elem()
-		}
-		arg.Type = fmt.Sprintf("map[%s]%s", key.Name(), p.Name())
-	}
-
-	return arg
+	return v.Name()
 }
 
 // ExtractEndpoint extract *Endpoint from reflect.Method
@@ -116,7 +67,7 @@ func ExtractEndpoint(method reflect.Method) *Endpoint {
 
 	request := ExtractValue(reqType, 0)
 	response := ExtractValue(rspType, 0)
-	if request == nil || response == nil {
+	if request == "" || response == "" {
 		return nil
 	}
 
@@ -135,7 +86,7 @@ func ExtractEndpoint(method reflect.Method) *Endpoint {
 }
 
 // ExtractSubValue exctact *Value from reflect.Type
-func ExtractSubValue(typ reflect.Type) *Value {
+func ExtractSubValue(typ reflect.Type) string {
 	var reqType reflect.Type
 	switch typ.NumIn() {
 	case 1:
@@ -145,7 +96,7 @@ func ExtractSubValue(typ reflect.Type) *Value {
 	case 3:
 		reqType = typ.In(2)
 	default:
-		return nil
+		return ""
 	}
 	return ExtractValue(reqType, 0)
 }

register/extractor_test.go

@@ -36,28 +36,21 @@ func TestExtractEndpoint(t *testing.T) {
 		t.Fatalf("Expected handler Test, got %s", endpoints[0].Name)
 	}
 
-	if endpoints[0].Request == nil {
+	if endpoints[0].Request == "" {
 		t.Fatal("Expected non nil Request")
 	}
 
-	if endpoints[0].Response == nil {
+	if endpoints[0].Response == "" {
 		t.Fatal("Expected non nil Request")
 	}
 
-	if endpoints[0].Request.Name != "TestRequest" {
-		t.Fatalf("Expected TestRequest got %s", endpoints[0].Request.Name)
+	if endpoints[0].Request != "TestRequest" {
+		t.Fatalf("Expected TestRequest got %s", endpoints[0].Request)
 	}
 
-	if endpoints[0].Response.Name != "TestResponse" {
-		t.Fatalf("Expected TestResponse got %s", endpoints[0].Response.Name)
-	}
-
-	if endpoints[0].Request.Type != "TestRequest" {
-		t.Fatalf("Expected TestRequest type got %s", endpoints[0].Request.Type)
-	}
-
-	if endpoints[0].Response.Type != "TestResponse" {
-		t.Fatalf("Expected TestResponse type got %s", endpoints[0].Response.Type)
+	if endpoints[0].Response != "TestResponse" {
+		t.Fatalf("Expected TestResponse got %s", endpoints[0].Response)
 	}
 
+	t.Logf("XXX %#+v\n", endpoints[0])
 }

register/memory.go

@@ -30,10 +30,9 @@ type record struct {
 }
 
 type memory struct {
-	opts Options
-	// records is a KV map with domain name as the key and a services map as the value
 	records  map[string]services
 	watchers map[string]*watcher
+	opts     Options
 	sync.RWMutex
 }
 
@@ -65,7 +64,7 @@ func (m *memory) ttlPrune() {
 					for id, n := range record.Nodes {
 						if n.TTL != 0 && time.Since(n.LastSeen) > n.TTL {
 							if m.opts.Logger.V(logger.DebugLevel) {
-								m.opts.Logger.Debugf(m.opts.Context, "Register TTL expired for node %s of service %s", n.Id, service)
+								m.opts.Logger.Debugf(m.opts.Context, "Register TTL expired for node %s of service %s", n.ID, service)
 							}
 							delete(m.records[domain][service][version].Nodes, id)
 						}
@@ -162,7 +161,7 @@ func (m *memory) Register(ctx context.Context, s *Service, opts ...RegisterOptio
 
 	for _, n := range s.Nodes {
 		// check if already exists
-		if _, ok := srvs[s.Name][s.Version].Nodes[n.Id]; ok {
+		if _, ok := srvs[s.Name][s.Version].Nodes[n.ID]; ok {
 			continue
 		}
 
@@ -177,9 +176,9 @@ func (m *memory) Register(ctx context.Context, s *Service, opts ...RegisterOptio
 		metadata["domain"] = options.Domain
 
 		// add the node
-		srvs[s.Name][s.Version].Nodes[n.Id] = &node{
+		srvs[s.Name][s.Version].Nodes[n.ID] = &node{
 			Node: &Node{
-				Id:       n.Id,
+				ID:       n.ID,
 				Address:  n.Address,
 				Metadata: metadata,
 			},
@@ -201,8 +200,8 @@ func (m *memory) Register(ctx context.Context, s *Service, opts ...RegisterOptio
 			if m.opts.Logger.V(logger.DebugLevel) {
 				m.opts.Logger.Debugf(m.opts.Context, "Updated registration for service: %s, version: %s", s.Name, s.Version)
 			}
-			srvs[s.Name][s.Version].Nodes[n.Id].TTL = options.TTL
-			srvs[s.Name][s.Version].Nodes[n.Id].LastSeen = time.Now()
+			srvs[s.Name][s.Version].Nodes[n.ID].TTL = options.TTL
+			srvs[s.Name][s.Version].Nodes[n.ID].LastSeen = time.Now()
 		}
 	}
 
@@ -242,11 +241,11 @@ func (m *memory) Deregister(ctx context.Context, s *Service, opts ...DeregisterO
 
 	// deregister all of the service nodes from this version
 	for _, n := range s.Nodes {
-		if _, ok := version.Nodes[n.Id]; ok {
+		if _, ok := version.Nodes[n.ID]; ok {
 			if m.opts.Logger.V(logger.DebugLevel) {
 				m.opts.Logger.Debugf(m.opts.Context, "Register removed node from service: %s, version: %s", s.Name, s.Version)
 			}
-			delete(version.Nodes, n.Id)
+			delete(version.Nodes, n.ID)
 		}
 	}
 
@@ -458,7 +457,7 @@ func serviceToRecord(s *Service, ttl time.Duration) *record {
 
 	nodes := make(map[string]*node, len(s.Nodes))
 	for _, n := range s.Nodes {
-		nodes[n.Id] = &node{
+		nodes[n.ID] = &node{
 			Node:     n,
 			TTL:      ttl,
 			LastSeen: time.Now(),
@@ -490,40 +489,31 @@ func recordToService(r *record, domain string) *Service {
 
 	endpoints := make([]*Endpoint, len(r.Endpoints))
 	for i, e := range r.Endpoints {
-		request := new(Value)
-		if e.Request != nil {
-			*request = *e.Request
-		}
-		response := new(Value)
-		if e.Response != nil {
-			*response = *e.Response
-		}
-
-		metadata := make(map[string]string, len(e.Metadata))
+		md := make(map[string]string, len(e.Metadata))
 		for k, v := range e.Metadata {
-			metadata[k] = v
+			md[k] = v
 		}
 
 		endpoints[i] = &Endpoint{
 			Name:     e.Name,
-			Request:  request,
-			Response: response,
-			Metadata: metadata,
+			Request:  e.Request,
+			Response: e.Response,
+			Metadata: md,
 		}
 	}
 
 	nodes := make([]*Node, len(r.Nodes))
 	i := 0
 	for _, n := range r.Nodes {
-		metadata := make(map[string]string, len(n.Metadata))
+		md := make(map[string]string, len(n.Metadata))
 		for k, v := range n.Metadata {
-			metadata[k] = v
+			md[k] = v
 		}
 
 		nodes[i] = &Node{
-			Id:       n.Id,
+			ID:       n.ID,
 			Address:  n.Address,
-			Metadata: metadata,
+			Metadata: md,
 		}
 		i++
 	}

register/memory_test.go

@@ -8,72 +8,70 @@ import (
 	"time"
 )
 
-var (
-	testData = map[string][]*Service{
-		"foo": {
-			{
-				Name:    "foo",
-				Version: "1.0.0",
-				Nodes: []*Node{
-					{
-						Id:      "foo-1.0.0-123",
-						Address: "localhost:9999",
-					},
-					{
-						Id:      "foo-1.0.0-321",
-						Address: "localhost:9999",
-					},
+var testData = map[string][]*Service{
+	"foo": {
+		{
+			Name:    "foo",
+			Version: "1.0.0",
+			Nodes: []*Node{
+				{
+					ID:      "foo-1.0.0-123",
+					Address: "localhost:9999",
 				},
-			},
-			{
-				Name:    "foo",
-				Version: "1.0.1",
-				Nodes: []*Node{
-					{
-						Id:      "foo-1.0.1-321",
-						Address: "localhost:6666",
-					},
-				},
-			},
-			{
-				Name:    "foo",
-				Version: "1.0.3",
-				Nodes: []*Node{
-					{
-						Id:      "foo-1.0.3-345",
-						Address: "localhost:8888",
-					},
+				{
+					ID:      "foo-1.0.0-321",
+					Address: "localhost:9999",
 				},
 			},
 		},
-		"bar": {
-			{
-				Name:    "bar",
-				Version: "default",
-				Nodes: []*Node{
-					{
-						Id:      "bar-1.0.0-123",
-						Address: "localhost:9999",
-					},
-					{
-						Id:      "bar-1.0.0-321",
-						Address: "localhost:9999",
-					},
-				},
-			},
-			{
-				Name:    "bar",
-				Version: "latest",
-				Nodes: []*Node{
-					{
-						Id:      "bar-1.0.1-321",
-						Address: "localhost:6666",
-					},
+		{
+			Name:    "foo",
+			Version: "1.0.1",
+			Nodes: []*Node{
+				{
+					ID:      "foo-1.0.1-321",
+					Address: "localhost:6666",
 				},
 			},
 		},
-	}
-)
+		{
+			Name:    "foo",
+			Version: "1.0.3",
+			Nodes: []*Node{
+				{
+					ID:      "foo-1.0.3-345",
+					Address: "localhost:8888",
+				},
+			},
+		},
+	},
+	"bar": {
+		{
+			Name:    "bar",
+			Version: "default",
+			Nodes: []*Node{
+				{
+					ID:      "bar-1.0.0-123",
+					Address: "localhost:9999",
+				},
+				{
+					ID:      "bar-1.0.0-321",
+					Address: "localhost:9999",
+				},
+			},
+		},
+		{
+			Name:    "bar",
+			Version: "latest",
+			Nodes: []*Node{
+				{
+					ID:      "bar-1.0.1-321",
+					Address: "localhost:6666",
+				},
+			},
+		},
+	},
+}
 
 //nolint:gocyclo
 func TestMemoryRegistry(t *testing.T) {

register/options.go

@@ -44,6 +44,7 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// nolint: golint
 // RegisterOptions holds options for register method
 type RegisterOptions struct {
 	Context  context.Context
@@ -196,6 +197,7 @@ func TLSConfig(t *tls.Config) Option {
 	}
 }
 
+// nolint: golint
 // RegisterAttempts specifies register atempts count
 func RegisterAttempts(t int) RegisterOption {
 	return func(o *RegisterOptions) {
@@ -203,6 +205,7 @@ func RegisterAttempts(t int) RegisterOption {
 	}
 }
 
+// nolint: golint
 // RegisterTTL specifies register ttl
 func RegisterTTL(t time.Duration) RegisterOption {
 	return func(o *RegisterOptions) {
@@ -210,6 +213,7 @@ func RegisterTTL(t time.Duration) RegisterOption {
 	}
 }
 
+// nolint: golint
 // RegisterContext sets the register context
 func RegisterContext(ctx context.Context) RegisterOption {
 	return func(o *RegisterOptions) {
@@ -217,6 +221,7 @@ func RegisterContext(ctx context.Context) RegisterOption {
 	}
 }
 
+// nolint: golint
 // RegisterDomain secifies register domain
 func RegisterDomain(d string) RegisterOption {
 	return func(o *RegisterOptions) {

register/register.go

@@ -53,29 +53,23 @@ type Service struct {
 // Node holds node register info
 type Node struct {
 	Metadata metadata.Metadata `json:"metadata"`
-	Id       string            `json:"id"`
+	ID       string            `json:"id"`
 	Address  string            `json:"address"`
 }
 
 // Endpoint holds endpoint register info
 type Endpoint struct {
-	Request  *Value            `json:"request"`
-	Response *Value            `json:"response"`
+	Request  string            `json:"request"`
+	Response string            `json:"response"`
 	Metadata metadata.Metadata `json:"metadata"`
 	Name     string            `json:"name"`
 }
 
-// Value holds additional kv stuff
-type Value struct {
-	Name   string   `json:"name"`
-	Type   string   `json:"type"`
-	Values []*Value `json:"values"`
-}
-
 // Option func signature
 type Option func(*Options)
 
 // RegisterOption option is used to register service
+// nolint: golint
 type RegisterOption func(*RegisterOptions)
 
 // WatchOption option is used to watch service changes

register/watcher.go

@@ -52,8 +52,8 @@ type Event struct {
 	Timestamp time.Time
 	// Service is register service
 	Service *Service
-	// Id is register id
-	Id string
+	// ID is register id
+	ID string
 	// Type defines type of event
 	Type EventType
 }

router/dns.go

@@ -0,0 +1,91 @@
+package router
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+)
+
+// NewRouter returns an initialized dns router
+func NewRouter(opts ...Option) Router {
+	options := NewOptions(opts...)
+	return &dns{options}
+}
+
+type dns struct {
+	options Options
+}
+
+func (d *dns) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&d.options)
+	}
+	return nil
+}
+
+func (d *dns) Options() Options {
+	return d.options
+}
+
+func (d *dns) Table() Table {
+	return nil
+}
+
+func (d *dns) Close() error {
+	return nil
+}
+
+func (d *dns) Lookup(opts ...QueryOption) ([]Route, error) {
+	options := NewQuery(opts...)
+	// check to see if we have the port provided in the service, e.g. go-micro-srv-foo:8000
+	host, port, err := net.SplitHostPort(options.Service)
+	if err == nil {
+		// lookup the service using A records
+		ips, err := net.LookupHost(host)
+		if err != nil {
+			return nil, err
+		}
+
+		p, _ := strconv.Atoi(port)
+
+		// convert the ip addresses to routes
+		result := make([]Route, len(ips))
+		for i, ip := range ips {
+			result[i] = Route{
+				Service: options.Service,
+				Address: fmt.Sprintf("%s:%d", ip, uint16(p)),
+			}
+		}
+		return result, nil
+	}
+
+	// we didn't get the port so we'll lookup the service using SRV records. If we can't lookup the
+	// service using the SRV record, we return the error.
+	_, nodes, err := net.LookupSRV(options.Service, "tcp", d.options.Network)
+	if err != nil {
+		return nil, err
+	}
+
+	// convert the nodes (net services) to routes
+	result := make([]Route, len(nodes))
+	for i, n := range nodes {
+		result[i] = Route{
+			Service: options.Service,
+			Address: fmt.Sprintf("%s:%d", n.Target, n.Port),
+			Network: d.options.Network,
+		}
+	}
+	return result, nil
+}
+
+func (d *dns) Watch(opts ...WatchOption) (Watcher, error) {
+	return nil, nil
+}
+
+func (d *dns) Name() string {
+	return d.options.Name
+}
+
+func (d *dns) String() string {
+	return "dns"
+}

router/router.go

@@ -7,7 +7,7 @@ import (
 
 var (
 	// DefaultRouter is the global default router
-	DefaultRouter Router
+	DefaultRouter Router = NewRouter()
 	// DefaultNetwork is default micro network
 	DefaultNetwork = "micro"
 	// ErrRouteNotFound is returned when no route was found in the routing table

router/watcher.go

@@ -5,10 +5,8 @@ import (
 	"time"
 )
 
-var (
-	// ErrWatcherStopped is returned when routing table watcher has been stopped
-	ErrWatcherStopped = errors.New("watcher stopped")
-)
+// ErrWatcherStopped is returned when routing table watcher has been stopped
+var ErrWatcherStopped = errors.New("watcher stopped")
 
 // EventType defines routing table event
 type EventType int
@@ -38,12 +36,12 @@ func (t EventType) String() string {
 
 // Event is returned by a call to Next on the watcher.
 type Event struct {
-	// Route is table route
-	Route Route
 	// Timestamp is event timestamp
 	Timestamp time.Time
 	// Id of the event
 	Id string
+	// Route is table route
+	Route Route
 	// Type defines type of event
 	Type EventType
 }

runtime/runtime.go

@@ -8,10 +8,8 @@ import (
 	"github.com/unistack-org/micro/v3/metadata"
 )
 
-var (
-	// ErrAlreadyExists error
-	ErrAlreadyExists = errors.New("already exists")
-)
+// ErrAlreadyExists error
+var ErrAlreadyExists = errors.New("already exists")
 
 // Runtime is a service runtime manager
 type Runtime interface {

selector/selector.go

@@ -5,10 +5,8 @@ import (
 	"errors"
 )
 
-var (
-	// ErrNoneAvailable is returned by select when no routes were provided to select from
-	ErrNoneAvailable = errors.New("none available")
-)
+// ErrNoneAvailable is returned by select when no routes were provided to select from
+var ErrNoneAvailable = errors.New("none available")
 
 // Selector selects a route from a pool
 type Selector interface {

server/generate.go

@@ -0,0 +1,3 @@
+package server
+
+//go:generate protoc -I./health -I../ -I/home/vtolstov/.cache/go-path/pkg/mod/github.com/unistack-org/micro-proto@v0.0.1 --micro_out=components=micro|http|server,standalone=false,debug=true,paths=source_relative:./health health/health.proto

server/handler.go

@@ -13,7 +13,7 @@ type rpcHandler struct {
 	endpoints []*register.Endpoint
 }
 
-func newRpcHandler(handler interface{}, opts ...HandlerOption) Handler {
+func newRPCHandler(handler interface{}, opts ...HandlerOption) Handler {
 	options := NewHandlerOptions(opts...)
 
 	typ := reflect.TypeOf(handler)

server/health/health.go

@@ -0,0 +1,82 @@
+package health
+
+import (
+	"context"
+
+	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/errors"
+)
+
+var _ HealthServer = &Handler{}
+
+type Handler struct {
+	opts Options
+}
+
+type CheckFunc func(context.Context) error
+
+type Option func(*Options)
+
+type Options struct {
+	Version     string
+	Name        string
+	LiveChecks  []CheckFunc
+	ReadyChecks []CheckFunc
+}
+
+func LiveChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.LiveChecks = append(o.LiveChecks, fns...)
+	}
+}
+
+func ReadyChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.ReadyChecks = append(o.ReadyChecks, fns...)
+	}
+}
+
+func Name(name string) Option {
+	return func(o *Options) {
+		o.Name = name
+	}
+}
+
+func Version(version string) Option {
+	return func(o *Options) {
+		o.Version = version
+	}
+}
+
+func NewHandler(opts ...Option) *Handler {
+	options := Options{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &Handler{opts: options}
+}
+
+func (h *Handler) Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	var err error
+	for _, fn := range h.opts.LiveChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *Handler) Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	var err error
+	for _, fn := range h.opts.ReadyChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *Handler) Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	rsp.Data = []byte(h.opts.Version)
+	return nil
+}

server/health/health.proto

@@ -0,0 +1,62 @@
+syntax = "proto3";
+
+package micro.server.health;
+option go_package = "github.com/unistack-org/micro/v3/server/health;health";
+
+import "api/annotations.proto";
+import "openapiv2/annotations.proto";
+import "codec/frame.proto";
+
+service Health {
+	rpc Live(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Live";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/live"; };
+  };
+	rpc Ready(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Ready";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/ready"; };
+  };
+	rpc Version(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Version";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/version"; };
+  };
+};

server/health/health_micro.pb.go

@@ -0,0 +1,38 @@
+// Code generated by protoc-gen-micro
+// source: health.proto
+package health
+
+import (
+	context "context"
+	api "github.com/unistack-org/micro/v3/api"
+	codec "github.com/unistack-org/micro/v3/codec"
+)
+
+func NewHealthEndpoints() []*api.Endpoint {
+	return []*api.Endpoint{
+		&api.Endpoint{
+			Name:    "Health.Live",
+			Path:    []string{"/live"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+		&api.Endpoint{
+			Name:    "Health.Ready",
+			Path:    []string{"/ready"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+		&api.Endpoint{
+			Name:    "Health.Version",
+			Path:    []string{"/version"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+	}
+}
+
+type HealthServer interface {
+	Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+}

server/health/health_micro_http.pb.go

@@ -0,0 +1,43 @@
+// Code generated by protoc-gen-micro
+// source: health.proto
+package health
+
+import (
+	context "context"
+	api "github.com/unistack-org/micro/v3/api"
+	codec "github.com/unistack-org/micro/v3/codec"
+	server "github.com/unistack-org/micro/v3/server"
+)
+
+type healthServer struct {
+	HealthServer
+}
+
+func (h *healthServer) Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Live(ctx, req, rsp)
+}
+
+func (h *healthServer) Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Ready(ctx, req, rsp)
+}
+
+func (h *healthServer) Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Version(ctx, req, rsp)
+}
+
+func RegisterHealthServer(s server.Server, sh HealthServer, opts ...server.HandlerOption) error {
+	type health interface {
+		Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	}
+	type Health struct {
+		health
+	}
+	h := &healthServer{sh}
+	var nopts []server.HandlerOption
+	for _, endpoint := range NewHealthEndpoints() {
+		nopts = append(nopts, api.WithEndpoint(endpoint))
+	}
+	return s.Handle(s.NewHandler(&Health{h}, append(nopts, opts...)...))
+}

server/noop.go

@@ -6,39 +6,32 @@ import (
 	"sync"
 	"time"
 
-	//	cjson "github.com/unistack-org/micro-codec-json"
-	//	cjsonrpc "github.com/unistack-org/micro-codec-jsonrpc"
-	//	cproto "github.com/unistack-org/micro-codec-proto"
-	//	cprotorpc "github.com/unistack-org/micro-codec-protorpc"
 	"github.com/unistack-org/micro/v3/broker"
 	"github.com/unistack-org/micro/v3/codec"
 	"github.com/unistack-org/micro/v3/logger"
 	"github.com/unistack-org/micro/v3/register"
+	maddr "github.com/unistack-org/micro/v3/util/addr"
+	mnet "github.com/unistack-org/micro/v3/util/net"
+	"github.com/unistack-org/micro/v3/util/rand"
 )
 
-var (
-	// DefaultCodecs will be used to encode/decode
-	DefaultCodecs = map[string]codec.Codec{
-		//"application/json":         cjson.NewCodec,
-		//"application/json-rpc":     cjsonrpc.NewCodec,
-		//"application/protobuf":     cproto.NewCodec,
-		//"application/proto-rpc":    cprotorpc.NewCodec,
-		"application/octet-stream": codec.NewCodec(),
-	}
-)
+// DefaultCodecs will be used to encode/decode
+var DefaultCodecs = map[string]codec.Codec{
+	"application/octet-stream": codec.NewCodec(),
+}
 
 const (
 	defaultContentType = "application/json"
 )
 
 type noopServer struct {
-	opts        Options
 	h           Handler
+	wg          *sync.WaitGroup
 	rsvc        *register.Service
 	handlers    map[string]Handler
 	subscribers map[*subscriber][]broker.Subscriber
 	exit        chan chan error
-	wg          *sync.WaitGroup
+	opts        Options
 	sync.RWMutex
 	registered bool
 	started    bool
@@ -82,8 +75,7 @@ func (n *noopServer) Subscribe(sb Subscriber) error {
 	sub, ok := sb.(*subscriber)
 	if !ok {
 		return fmt.Errorf("invalid subscriber: expected *subscriber")
-	}
-	if len(sub.handlers) == 0 {
+	} else if len(sub.handlers) == 0 {
 		return fmt.Errorf("invalid subscriber: no handler functions")
 	}
 
@@ -103,7 +95,7 @@ func (n *noopServer) Subscribe(sb Subscriber) error {
 }
 
 func (n *noopServer) NewHandler(h interface{}, opts ...HandlerOption) Handler {
-	return newRpcHandler(h, opts...)
+	return newRPCHandler(h, opts...)
 }
 
 func (n *noopServer) NewSubscriber(topic string, sb interface{}, opts ...SubscriberOption) Subscriber {
@@ -116,11 +108,12 @@ func (n *noopServer) Init(opts ...Option) error {
 	}
 
 	if n.handlers == nil {
-		n.handlers = make(map[string]Handler)
+		n.handlers = make(map[string]Handler, 1)
 	}
 	if n.subscribers == nil {
-		n.subscribers = make(map[*subscriber][]broker.Subscriber)
+		n.subscribers = make(map[*subscriber][]broker.Subscriber, 1)
 	}
+
 	if n.exit == nil {
 		n.exit = make(chan chan error)
 	}
@@ -158,23 +151,16 @@ func (n *noopServer) Register() error {
 	}
 
 	n.RLock()
-	// Maps are ordered randomly, sort the keys for consistency
-	var handlerList []string
-	for n, e := range n.handlers {
-		// Only advertise non internal handlers
-		if !e.Options().Internal {
-			handlerList = append(handlerList, n)
-		}
+	handlerList := make([]string, 0, len(n.handlers))
+	for n := range n.handlers {
+		handlerList = append(handlerList, n)
 	}
 
 	sort.Strings(handlerList)
 
-	var subscriberList []*subscriber
+	subscriberList := make([]*subscriber, 0, len(n.subscribers))
 	for e := range n.subscribers {
-		// Only advertise non internal subscribers
-		if !e.Options().Internal {
-			subscriberList = append(subscriberList, e)
-		}
+		subscriberList = append(subscriberList, e)
 	}
 	sort.Slice(subscriberList, func(i, j int) bool {
 		return subscriberList[i].topic > subscriberList[j].topic
@@ -190,7 +176,7 @@ func (n *noopServer) Register() error {
 	n.RUnlock()
 
 	service.Nodes[0].Metadata["protocol"] = "noop"
-	service.Nodes[0].Metadata["transport"] = "noop"
+	service.Nodes[0].Metadata["transport"] = service.Nodes[0].Metadata["protocol"]
 	service.Endpoints = endpoints
 
 	n.RLock()
@@ -199,7 +185,7 @@ func (n *noopServer) Register() error {
 
 	if !registered {
 		if config.Logger.V(logger.InfoLevel) {
-			config.Logger.Infof(n.opts.Context, "register [%s] Registering node: %s", config.Register.String(), service.Nodes[0].Id)
+			config.Logger.Infof(n.opts.Context, "register [%s] Registering node: %s", config.Register.String(), service.Nodes[0].ID)
 		}
 	}
 
@@ -218,26 +204,34 @@ func (n *noopServer) Register() error {
 
 	cx := config.Context
 
-	for sb := range n.subscribers {
-		handler := n.createSubHandler(sb, config)
-		var opts []broker.SubscribeOption
-		if queue := sb.Options().Queue; len(queue) > 0 {
-			opts = append(opts, broker.SubscribeGroup(queue))
-		}
+	var sub broker.Subscriber
 
+	for sb := range n.subscribers {
 		if sb.Options().Context != nil {
 			cx = sb.Options().Context
 		}
 
-		opts = append(opts, broker.SubscribeContext(cx), broker.SubscribeAutoAck(sb.Options().AutoAck))
+		opts := []broker.SubscribeOption{broker.SubscribeContext(cx), broker.SubscribeAutoAck(sb.Options().AutoAck)}
+		if queue := sb.Options().Queue; len(queue) > 0 {
+			opts = append(opts, broker.SubscribeGroup(queue))
+		}
+
+		if sb.Options().Batch {
+			// batch processing handler
+			sub, err = config.Broker.BatchSubscribe(cx, sb.Topic(), n.newBatchSubHandler(sb, config), opts...)
+		} else {
+			// single processing handler
+			sub, err = config.Broker.Subscribe(cx, sb.Topic(), n.newSubHandler(sb, config), opts...)
+		}
+
+		if err != nil {
+			return err
+		}
 
 		if config.Logger.V(logger.InfoLevel) {
 			config.Logger.Infof(n.opts.Context, "subscribing to topic: %s", sb.Topic())
 		}
-		sub, err := config.Broker.Subscribe(cx, sb.Topic(), handler, opts...)
-		if err != nil {
-			return err
-		}
+
 		n.subscribers[sb] = []broker.Subscriber{sub}
 	}
 
@@ -262,7 +256,7 @@ func (n *noopServer) Deregister() error {
 	}
 
 	if config.Logger.V(logger.InfoLevel) {
-		config.Logger.Infof(n.opts.Context, "deregistering node: %s", service.Nodes[0].Id)
+		config.Logger.Infof(n.opts.Context, "deregistering node: %s", service.Nodes[0].ID)
 	}
 
 	if err := DefaultDeregisterFunc(service, config); err != nil {
@@ -319,9 +313,22 @@ func (n *noopServer) Start() error {
 	config := n.Options()
 	n.RUnlock()
 
+	// use 127.0.0.1 to avoid scan of all network interfaces
+	addr, err := maddr.Extract("127.0.0.1")
+	if err != nil {
+		return err
+	}
+	var rng rand.Rand
+	i := rng.Intn(20000)
+	// set addr with port
+	addr = mnet.HostPort(addr, 10000+i)
+
+	config.Address = addr
+
 	if config.Logger.V(logger.InfoLevel) {
 		config.Logger.Infof(n.opts.Context, "server [noop] Listening on %s", config.Address)
 	}
+
 	n.Lock()
 	if len(config.Advertise) == 0 {
 		config.Advertise = config.Address
@@ -344,9 +351,10 @@ func (n *noopServer) Start() error {
 	}
 
 	// use RegisterCheck func before register
+	// nolint: nestif
 	if err := config.RegisterCheck(config.Context); err != nil {
 		if config.Logger.V(logger.ErrorLevel) {
-			config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s", config.Name, config.Id, err)
+			config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s", config.Name, config.ID, err)
 		}
 	} else {
 		// announce self to the world
@@ -378,25 +386,26 @@ func (n *noopServer) Start() error {
 				registered := n.registered
 				n.RUnlock()
 				rerr := config.RegisterCheck(config.Context)
+				// nolint: nestif
 				if rerr != nil && registered {
 					if config.Logger.V(logger.ErrorLevel) {
-						config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s, deregister it", config.Name, config.Id, rerr)
+						config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s, deregister it", config.Name, config.ID, rerr)
 					}
 					// deregister self in case of error
 					if err := n.Deregister(); err != nil {
 						if config.Logger.V(logger.ErrorLevel) {
-							config.Logger.Errorf(n.opts.Context, "server %s-%s deregister error: %s", config.Name, config.Id, err)
+							config.Logger.Errorf(n.opts.Context, "server %s-%s deregister error: %s", config.Name, config.ID, err)
 						}
 					}
 				} else if rerr != nil && !registered {
 					if config.Logger.V(logger.ErrorLevel) {
-						config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s", config.Name, config.Id, rerr)
+						config.Logger.Errorf(n.opts.Context, "server %s-%s register check error: %s", config.Name, config.ID, rerr)
 					}
 					continue
 				}
 				if err := n.Register(); err != nil {
 					if config.Logger.V(logger.ErrorLevel) {
-						config.Logger.Errorf(n.opts.Context, "server %s-%s register error: %s", config.Name, config.Id, err)
+						config.Logger.Errorf(n.opts.Context, "server %s-%s register error: %s", config.Name, config.ID, err)
 					}
 				}
 			// wait for exit

server/noop_test.go

@@ -0,0 +1,106 @@
+package server_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/unistack-org/micro/v3/broker"
+	"github.com/unistack-org/micro/v3/client"
+	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/metadata"
+	"github.com/unistack-org/micro/v3/server"
+)
+
+type TestHandler struct {
+	t *testing.T
+}
+
+type TestMessage struct {
+	Name string
+}
+
+var (
+	numMsg int = 8
+)
+
+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)
+	}
+
+	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

@@ -57,8 +57,8 @@ type Options struct {
 	RegisterCheck func(context.Context) error
 	// Codecs map to handle content-type
 	Codecs map[string]codec.Codec
-	// Id holds the id of the server
-	Id string
+	// ID holds the id of the server
+	ID string
 	// Namespace for te server
 	Namespace string
 	// Name holds the server name
@@ -71,6 +71,8 @@ type Options struct {
 	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
@@ -104,7 +106,7 @@ func NewOptions(opts ...Option) Options {
 		Address:          DefaultAddress,
 		Name:             DefaultName,
 		Version:          DefaultVersion,
-		Id:               DefaultId,
+		ID:               DefaultID,
 		Namespace:        DefaultNamespace,
 	}
 
@@ -143,10 +145,10 @@ func Meter(m meter.Meter) Option {
 	}
 }
 
-// Id unique server id
-func Id(id string) Option {
+// ID unique server id
+func ID(id string) Option {
 	return func(o *Options) {
-		o.Id = id
+		o.ID = id
 	}
 }
 
@@ -302,6 +304,13 @@ func WrapSubscriber(w SubscriberWrapper) Option {
 	}
 }
 
+// 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) {
@@ -325,8 +334,6 @@ type HandlerOptions struct {
 	Context context.Context
 	// Metadata for hondler
 	Metadata map[string]metadata.Metadata
-	// Internal flag limits exporting to other nodes via register
-	Internal bool
 }
 
 // NewHandlerOptions creates new HandlerOptions
@@ -354,10 +361,14 @@ type SubscriberOptions struct {
 	Queue string
 	// AutoAck flag for auto ack messages after processing
 	AutoAck bool
-	// Internal flag limit exporting info via register
-	Internal 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
@@ -382,23 +393,6 @@ func EndpointMetadata(name string, md metadata.Metadata) HandlerOption {
 	}
 }
 
-// InternalHandler options specifies that a handler is not advertised
-// to the discovery system. In the future this may also limit request
-// to the internal network or authorised user.
-func InternalHandler(b bool) HandlerOption {
-	return func(o *HandlerOptions) {
-		o.Internal = b
-	}
-}
-
-// InternalSubscriber options specifies that a subscriber is not advertised
-// to the discovery system.
-func InternalSubscriber(b bool) SubscriberOption {
-	return func(o *SubscriberOptions) {
-		o.Internal = b
-	}
-}
-
 // DisableAutoAck will disable auto acking of messages
 // after they have been handled.
 func DisableAutoAck() SubscriberOption {
@@ -434,3 +428,32 @@ func SubscriberContext(ctx context.Context) SubscriberOption {
 		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

@@ -72,7 +72,7 @@ func NewRegisterService(s Server) (*register.Service, error) {
 	}
 
 	node := &register.Node{
-		Id:      opts.Name + "-" + opts.Id,
+		ID:      opts.Name + "-" + opts.ID,
 		Address: net.JoinHostPort(addr, port),
 	}
 	node.Metadata = metadata.Copy(opts.Metadata)

server/server.go

@@ -11,20 +11,18 @@ import (
 	"github.com/unistack-org/micro/v3/register"
 )
 
-var (
-	// DefaultServer default server
-	DefaultServer Server = NewServer()
-)
+// DefaultServer default server
+var DefaultServer Server = NewServer()
 
 var (
-	// DefaultAddress will be used if no address passed
-	DefaultAddress = ":0"
+	// DefaultAddress will be used if no address passed, use secure localhost
+	DefaultAddress = "127.0.0.1:0"
 	// DefaultName will be used if no name passed
 	DefaultName = "server"
 	// DefaultVersion will be used if no version passed
 	DefaultVersion = "latest"
-	// DefaultId will be used if no id passed
-	DefaultId = uuid.New().String()
+	// DefaultID will be used if no id passed
+	DefaultID = uuid.New().String()
 	// DefaultRegisterCheck holds func that run before register server
 	DefaultRegisterCheck = func(context.Context) error { return nil }
 	// DefaultRegisterInterval holds interval for register

server/subscriber.go

@@ -18,14 +18,13 @@ import (
 )
 
 const (
-	subSig = "func(context.Context, interface{}) error"
+	subSig      = "func(context.Context, interface{}) error"
+	batchSubSig = "func([]context.Context, []interface{}) error"
 )
 
-var (
-	// Precompute the reflect type for error. Can't use error directly
-	// because Typeof takes an empty interface value. This is annoying.
-	typeOfError = reflect.TypeOf((*error)(nil)).Elem()
-)
+// 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
@@ -59,42 +58,49 @@ func isExportedOrBuiltinType(t reflect.Type) bool {
 	return isExported(t.Name()) || t.PkgPath() == ""
 }
 
-// ValidateSubscriber func
+// ValidateSubscriber func signature
 func ValidateSubscriber(sub Subscriber) error {
 	typ := reflect.TypeOf(sub.Subscriber())
 	var argType reflect.Type
-
-	if typ.Kind() == reflect.Func {
+	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("%s", 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", name, typ.NumIn(), subSig)
+			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 outs: %v require signature %s",
-				name, typ.NumOut(), subSig)
+			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())
 		}
-	} else {
+	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",
-					name, method.Name, method.Type.NumIn(), subSig)
+				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) {
@@ -102,8 +108,8 @@ func ValidateSubscriber(sub Subscriber) error {
 			}
 			if method.Type.NumOut() != 1 {
 				return fmt.Errorf(
-					"subscriber %v.%v has wrong number of outs: %v require signature %s",
-					name, method.Name, method.Type.NumOut(), subSig)
+					"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())
@@ -184,7 +190,125 @@ func newSubscriber(topic string, sub interface{}, opts ...SubscriberOption) Subs
 }
 
 //nolint:gocyclo
-func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handler {
+func (n *noopServer) newBatchSubHandler(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
+
+			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.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.Payload()))
+				}
+				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) newSubHandler(sb *subscriber, opts Options) broker.Handler {
 	return func(p broker.Event) (err error) {
 		defer func() {
 			if r := recover(); r != nil {
@@ -202,12 +326,12 @@ func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handl
 		msg := p.Message()
 		// if we don't have headers, create empty map
 		if msg.Header == nil {
-			msg.Header = make(map[string]string)
+			msg.Header = metadata.New(2)
 		}
 
 		ct := msg.Header["Content-Type"]
 		if len(ct) == 0 {
-			msg.Header["Content-Type"] = defaultContentType
+			msg.Header.Set(metadata.HeaderContentType, defaultContentType)
 			ct = defaultContentType
 		}
 		cf, err := n.newCodec(ct)
@@ -215,12 +339,12 @@ func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handl
 			return err
 		}
 
-		hdr := make(map[string]string, len(msg.Header))
+		hdr := metadata.New(len(msg.Header))
 		for k, v := range msg.Header {
 			if k == "Content-Type" {
 				continue
 			}
-			hdr[k] = v
+			hdr.Set(k, v)
 		}
 
 		ctx := metadata.NewIncomingContext(sb.opts.Context, hdr)
@@ -276,14 +400,14 @@ func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handl
 				if n.wg != nil {
 					defer n.wg.Done()
 				}
-				err := fn(ctx, &rpcMessage{
+				cerr := fn(ctx, &rpcMessage{
 					topic:       sb.topic,
 					contentType: ct,
 					payload:     req.Interface(),
 					header:      msg.Header,
 					body:        msg.Body,
 				})
-				results <- err
+				results <- cerr
 			}()
 		}
 		var errors []string
@@ -295,7 +419,6 @@ func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handl
 		if len(errors) > 0 {
 			err = fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n"))
 		}
-
 		return err
 	}
 }

server/wrapper.go

@@ -14,12 +14,20 @@ type HandlerFunc func(ctx context.Context, req Request, rsp interface{}) error
 // 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

@@ -103,48 +103,48 @@ func (s *service) Init(opts ...Option) error {
 			// skip config as the struct not passed
 			continue
 		}
-		if err = cfg.Init(config.Context(s.opts.Context)); err != nil {
+		if err = cfg.Init(config.Context(cfg.Options().Context)); err != nil {
 			return err
 		}
 
-		if err = cfg.Load(s.opts.Context); err != nil {
+		if err = cfg.Load(cfg.Options().Context); err != nil {
 			return err
 		}
 
 	}
 
 	for _, log := range s.opts.Loggers {
-		if err = log.Init(logger.WithContext(s.opts.Context)); err != nil {
+		if err = log.Init(logger.WithContext(log.Options().Context)); err != nil {
 			return err
 		}
 	}
 
 	for _, reg := range s.opts.Registers {
-		if err = reg.Init(register.Context(s.opts.Context)); err != nil {
+		if err = reg.Init(register.Context(reg.Options().Context)); err != nil {
 			return err
 		}
 	}
 
 	for _, brk := range s.opts.Brokers {
-		if err = brk.Init(broker.Context(s.opts.Context)); err != nil {
+		if err = brk.Init(broker.Context(brk.Options().Context)); err != nil {
 			return err
 		}
 	}
 
 	for _, str := range s.opts.Stores {
-		if err = str.Init(store.Context(s.opts.Context)); err != nil {
+		if err = str.Init(store.Context(str.Options().Context)); err != nil {
 			return err
 		}
 	}
 
 	for _, srv := range s.opts.Servers {
-		if err = srv.Init(server.Context(s.opts.Context)); err != nil {
+		if err = srv.Init(server.Context(srv.Options().Context)); err != nil {
 			return err
 		}
 	}
 
 	for _, cli := range s.opts.Clients {
-		if err = cli.Init(client.Context(s.opts.Context)); err != nil {
+		if err = cli.Init(client.Context(cli.Options().Context)); err != nil {
 			return err
 		}
 	}
@@ -162,7 +162,6 @@ func (s *service) Broker(names ...string) broker.Broker {
 		idx = getNameIndex(names[0], s.opts.Brokers)
 	}
 	return s.opts.Brokers[idx]
-
 }
 
 func (s *service) Tracer(names ...string) tracer.Tracer {

store/memory.go

@@ -28,24 +28,14 @@ func (m *memoryStore) Disconnect(ctx context.Context) error {
 }
 
 type memoryStore struct {
-	opts  Options
 	store *cache.Cache
+	opts  Options
 }
 
 func (m *memoryStore) key(prefix, key string) string {
 	return filepath.Join(prefix, key)
 }
 
-func (m *memoryStore) prefix(database, table string) string {
-	if len(database) == 0 {
-		database = m.opts.Database
-	}
-	if len(table) == 0 {
-		table = m.opts.Table
-	}
-	return filepath.Join(database, table)
-}
-
 func (m *memoryStore) exists(prefix, key string) error {
 	key = m.key(prefix, key)
 
@@ -80,15 +70,17 @@ func (m *memoryStore) delete(prefix, key string) {
 
 func (m *memoryStore) list(prefix string, limit, offset uint) []string {
 	allItems := m.store.Items()
-	allKeys := make([]string, len(allItems))
-	i := 0
+	allKeys := make([]string, 0, len(allItems))
 
 	for k := range allItems {
-		if !strings.HasPrefix(k, prefix+"/") {
+		if !strings.HasPrefix(k, prefix) {
 			continue
 		}
-		allKeys[i] = strings.TrimPrefix(k, prefix+"/")
-		i++
+		k = strings.TrimPrefix(k, prefix)
+		if k[0] == '/' {
+			k = k[1:]
+		}
+		allKeys = append(allKeys, k)
 	}
 
 	if limit != 0 || offset != 0 {
@@ -107,7 +99,6 @@ func (m *memoryStore) list(prefix string, limit, offset uint) []string {
 		}
 		return allKeys[offset:end]
 	}
-
 	return allKeys
 }
 
@@ -127,37 +118,48 @@ func (m *memoryStore) Name() string {
 }
 
 func (m *memoryStore) Exists(ctx context.Context, key string, opts ...ExistsOption) error {
-	prefix := m.prefix(m.opts.Database, m.opts.Table)
-	return m.exists(prefix, key)
+	options := NewExistsOptions(opts...)
+	if options.Namespace == "" {
+		options.Namespace = m.opts.Namespace
+	}
+	return m.exists(options.Namespace, key)
 }
 
 func (m *memoryStore) Read(ctx context.Context, key string, val interface{}, opts ...ReadOption) error {
-	readOpts := NewReadOptions(opts...)
-	prefix := m.prefix(readOpts.Database, readOpts.Table)
-	return m.get(prefix, key, val)
+	options := NewReadOptions(opts...)
+	if options.Namespace == "" {
+		options.Namespace = m.opts.Namespace
+	}
+	return m.get(options.Namespace, key, val)
 }
 
 func (m *memoryStore) Write(ctx context.Context, key string, val interface{}, opts ...WriteOption) error {
-	writeOpts := NewWriteOptions(opts...)
+	options := NewWriteOptions(opts...)
+	if options.Namespace == "" {
+		options.Namespace = m.opts.Namespace
+	}
+	if options.TTL == 0 {
+		options.TTL = cache.NoExpiration
+	}
 
-	prefix := m.prefix(writeOpts.Database, writeOpts.Table)
-
-	key = m.key(prefix, key)
+	key = m.key(options.Namespace, key)
 
 	buf, err := m.opts.Codec.Marshal(val)
 	if err != nil {
 		return err
 	}
 
-	m.store.Set(key, buf, writeOpts.TTL)
+	m.store.Set(key, buf, options.TTL)
 	return nil
 }
 
 func (m *memoryStore) Delete(ctx context.Context, key string, opts ...DeleteOption) error {
-	deleteOptions := NewDeleteOptions(opts...)
+	options := NewDeleteOptions(opts...)
+	if options.Namespace == "" {
+		options.Namespace = m.opts.Namespace
+	}
 
-	prefix := m.prefix(deleteOptions.Database, deleteOptions.Table)
-	m.delete(prefix, key)
+	m.delete(options.Namespace, key)
 	return nil
 }
 
@@ -166,25 +168,27 @@ func (m *memoryStore) Options() Options {
 }
 
 func (m *memoryStore) List(ctx context.Context, opts ...ListOption) ([]string, error) {
-	listOptions := NewListOptions(opts...)
+	options := NewListOptions(opts...)
+	if options.Namespace == "" {
+		options.Namespace = m.opts.Namespace
+	}
 
-	prefix := m.prefix(listOptions.Database, listOptions.Table)
-	keys := m.list(prefix, listOptions.Limit, listOptions.Offset)
+	keys := m.list(options.Namespace, options.Limit, options.Offset)
 
-	if len(listOptions.Prefix) > 0 {
+	if len(options.Prefix) > 0 {
 		var prefixKeys []string
 		for _, k := range keys {
-			if strings.HasPrefix(k, listOptions.Prefix) {
+			if strings.HasPrefix(k, options.Prefix) {
 				prefixKeys = append(prefixKeys, k)
 			}
 		}
 		keys = prefixKeys
 	}
 
-	if len(listOptions.Suffix) > 0 {
+	if len(options.Suffix) > 0 {
 		var suffixKeys []string
 		for _, k := range keys {
-			if strings.HasSuffix(k, listOptions.Suffix) {
+			if strings.HasSuffix(k, options.Suffix) {
 				suffixKeys = append(suffixKeys, k)
 			}
 		}

store/memory_test.go

@@ -9,11 +9,11 @@ import (
 )
 
 func TestMemoryReInit(t *testing.T) {
-	s := store.NewStore(store.Table("aaa"))
-	if err := s.Init(store.Table("")); err != nil {
+	s := store.NewStore(store.Namespace("aaa"))
+	if err := s.Init(store.Namespace("")); err != nil {
 		t.Fatal(err)
 	}
-	if len(s.Options().Table) > 0 {
+	if len(s.Options().Namespace) > 0 {
 		t.Error("Init didn't reinitialise the store")
 	}
 }
@@ -28,7 +28,7 @@ func TestMemoryBasic(t *testing.T) {
 
 func TestMemoryPrefix(t *testing.T) {
 	s := store.NewStore()
-	if err := s.Init(store.Table("some-prefix")); err != nil {
+	if err := s.Init(store.Namespace("some-prefix")); err != nil {
 		t.Fatal(err)
 	}
 	basictest(s, t)
@@ -36,7 +36,7 @@ func TestMemoryPrefix(t *testing.T) {
 
 func TestMemoryNamespace(t *testing.T) {
 	s := store.NewStore()
-	if err := s.Init(store.Database("some-namespace")); err != nil {
+	if err := s.Init(store.Namespace("some-namespace")); err != nil {
 		t.Fatal(err)
 	}
 	basictest(s, t)
@@ -44,7 +44,7 @@ func TestMemoryNamespace(t *testing.T) {
 
 func TestMemoryNamespacePrefix(t *testing.T) {
 	s := store.NewStore()
-	if err := s.Init(store.Table("some-prefix"), store.Database("some-namespace")); err != nil {
+	if err := s.Init(store.Namespace("some-namespace")); err != nil {
 		t.Fatal(err)
 	}
 	basictest(s, t)

store/options.go

@@ -28,13 +28,12 @@ type Options struct {
 	TLSConfig *tls.Config
 	// Name specifies store name
 	Name string
-	// Database specifies store database
-	Database string
-	// Table specifies store table
-	Table string
-	// Nodes contains store address
-	// TODO: replace with Addrs
-	Nodes []string
+	// Namespace of the records
+	Namespace string
+	// Addrs contains store address
+	Addrs []string
+	//Wrappers store wrapper that called before actual functions
+	//Wrappers []Wrapper
 }
 
 // NewOptions creates options struct
@@ -90,13 +89,20 @@ func Meter(m meter.Meter) Option {
 	}
 }
 
-// Name the name
+// Name the name of the store
 func Name(n string) Option {
 	return func(o *Options) {
 		o.Name = n
 	}
 }
 
+// Namespace sets namespace of the store
+func Namespace(ns string) Option {
+	return func(o *Options) {
+		o.Namespace = ns
+	}
+}
+
 // Tracer sets the tracer
 func Tracer(t tracer.Tracer) Option {
 	return func(o *Options) {
@@ -104,27 +110,21 @@ func Tracer(t tracer.Tracer) Option {
 	}
 }
 
-// Nodes contains the addresses or other connection information of the backing storage.
+// Addrs contains the addresses or other connection information of the backing storage.
 // For example, an etcd implementation would contain the nodes of the cluster.
 // A SQL implementation could contain one or more connection strings.
-func Nodes(a ...string) Option {
+func Addrs(addrs ...string) Option {
 	return func(o *Options) {
-		o.Nodes = a
+		o.Addrs = addrs
 	}
 }
 
-// Database allows multiple isolated stores to be kept in one backend, if supported.
-func Database(db string) Option {
-	return func(o *Options) {
-		o.Database = db
-	}
-}
-
-// Table is analag for a table in database backends or a key prefix in KV backends
-func Table(t string) Option {
-	return func(o *Options) {
-		o.Table = t
-	}
+// ReadOptions configures an individual Read operation
+type ReadOptions struct {
+	// Context holds external options
+	Context context.Context
+	// Namespace holds namespace
+	Namespace string
 }
 
 // NewReadOptions fills ReadOptions struct with opts slice
@@ -136,29 +136,35 @@ func NewReadOptions(opts ...ReadOption) ReadOptions {
 	return options
 }
 
-// ReadOptions configures an individual Read operation
-type ReadOptions struct {
-	// Context holds external options
-	Context context.Context
-	// Database holds the database name
-	Database string
-	// Table holds table name
-	Table string
-	// Namespace holds namespace
-	Namespace string
-}
-
 // ReadOption sets values in ReadOptions
 type ReadOption func(r *ReadOptions)
 
-// ReadFrom the database and table
-func ReadFrom(database, table string) ReadOption {
-	return func(r *ReadOptions) {
-		r.Database = database
-		r.Table = table
+// ReadContext pass context.Context to ReadOptions
+func ReadContext(ctx context.Context) ReadOption {
+	return func(o *ReadOptions) {
+		o.Context = ctx
 	}
 }
 
+// ReadNamespace pass namespace to ReadOptions
+func ReadNamespace(ns string) ReadOption {
+	return func(o *ReadOptions) {
+		o.Namespace = ns
+	}
+}
+
+// WriteOptions configures an individual Write operation
+type WriteOptions struct {
+	// Context holds external options
+	Context context.Context
+	// Metadata contains additional metadata
+	Metadata metadata.Metadata
+	// Namespace holds namespace
+	Namespace string
+	// TTL specifies key TTL
+	TTL time.Duration
+}
+
 // NewWriteOptions fills WriteOptions struct with opts slice
 func NewWriteOptions(opts ...WriteOption) WriteOptions {
 	options := WriteOptions{}
@@ -168,47 +174,45 @@ func NewWriteOptions(opts ...WriteOption) WriteOptions {
 	return options
 }
 
-// WriteOptions configures an individual Write operation
-type WriteOptions struct {
-	// Context holds external options
-	Context context.Context
-	// Metadata contains additional metadata
-	Metadata metadata.Metadata
-	// Database holds database name
-	Database string
-	// Table holds table name
-	Table string
-	// Namespace holds namespace
-	Namespace string
-	// TTL specifies key TTL
-	TTL time.Duration
-}
-
 // WriteOption sets values in WriteOptions
 type WriteOption func(w *WriteOptions)
 
-// WriteTo the database and table
-func WriteTo(database, table string) WriteOption {
-	return func(w *WriteOptions) {
-		w.Database = database
-		w.Table = table
-	}
-}
-
-// WriteTTL is the time the record expires
-func WriteTTL(d time.Duration) WriteOption {
-	return func(w *WriteOptions) {
-		w.TTL = d
+// WriteContext pass context.Context to wirte options
+func WriteContext(ctx context.Context) WriteOption {
+	return func(o *WriteOptions) {
+		o.Context = ctx
 	}
 }
 
 // WriteMetadata add metadata.Metadata
 func WriteMetadata(md metadata.Metadata) WriteOption {
-	return func(w *WriteOptions) {
-		w.Metadata = metadata.Copy(md)
+	return func(o *WriteOptions) {
+		o.Metadata = metadata.Copy(md)
 	}
 }
 
+// WriteTTL is the time the record expires
+func WriteTTL(d time.Duration) WriteOption {
+	return func(o *WriteOptions) {
+		o.TTL = d
+	}
+}
+
+// WriteNamespace pass namespace to write options
+func WriteNamespace(ns string) WriteOption {
+	return func(o *WriteOptions) {
+		o.Namespace = ns
+	}
+}
+
+// DeleteOptions configures an individual Delete operation
+type DeleteOptions struct {
+	// Context holds external options
+	Context context.Context
+	// Namespace holds namespace
+	Namespace string
+}
+
 // NewDeleteOptions fills DeleteOptions struct with opts slice
 func NewDeleteOptions(opts ...DeleteOption) DeleteOptions {
 	options := DeleteOptions{}
@@ -218,29 +222,33 @@ func NewDeleteOptions(opts ...DeleteOption) DeleteOptions {
 	return options
 }
 
-// DeleteOptions configures an individual Delete operation
-type DeleteOptions struct {
-	// Context holds external options
-	Context context.Context
-	// Database holds database name
-	Database string
-	// Table holds table name
-	Table string
-	// Namespace holds namespace
-	Namespace string
-}
-
 // DeleteOption sets values in DeleteOptions
 type DeleteOption func(d *DeleteOptions)
 
-// DeleteFrom the database and table
-func DeleteFrom(database, table string) DeleteOption {
-	return func(d *DeleteOptions) {
-		d.Database = database
-		d.Table = table
+// DeleteContext pass context.Context to delete options
+func DeleteContext(ctx context.Context) DeleteOption {
+	return func(o *DeleteOptions) {
+		o.Context = ctx
 	}
 }
 
+// DeleteNamespace pass namespace to delete options
+func DeleteNamespace(ns string) DeleteOption {
+	return func(o *DeleteOptions) {
+		o.Namespace = ns
+	}
+}
+
+// ListOptions configures an individual List operation
+type ListOptions struct {
+	Context   context.Context
+	Prefix    string
+	Suffix    string
+	Namespace string
+	Limit     uint
+	Offset    uint
+}
+
 // NewListOptions fills ListOptions struct with opts slice
 func NewListOptions(opts ...ListOption) ListOptions {
 	options := ListOptions{}
@@ -250,59 +258,50 @@ func NewListOptions(opts ...ListOption) ListOptions {
 	return options
 }
 
-// ListOptions configures an individual List operation
-type ListOptions struct {
-	Context   context.Context
-	Database  string
-	Prefix    string
-	Suffix    string
-	Namespace string
-	Table     string
-	Limit     uint
-	Offset    uint
-}
-
 // ListOption sets values in ListOptions
 type ListOption func(l *ListOptions)
 
-// ListFrom the database and table
-func ListFrom(database, table string) ListOption {
-	return func(l *ListOptions) {
-		l.Database = database
-		l.Table = table
+// ListContext pass context.Context to list options
+func ListContext(ctx context.Context) ListOption {
+	return func(o *ListOptions) {
+		o.Context = ctx
 	}
 }
 
 // ListPrefix returns all keys that are prefixed with key
-func ListPrefix(p string) ListOption {
-	return func(l *ListOptions) {
-		l.Prefix = p
+func ListPrefix(s string) ListOption {
+	return func(o *ListOptions) {
+		o.Prefix = s
 	}
 }
 
 // ListSuffix returns all keys that end with key
 func ListSuffix(s string) ListOption {
-	return func(l *ListOptions) {
-		l.Suffix = s
+	return func(o *ListOptions) {
+		o.Suffix = s
 	}
 }
 
-// ListLimit limits the number of returned keys to l
-func ListLimit(l uint) ListOption {
-	return func(lo *ListOptions) {
-		lo.Limit = l
+// ListLimit limits the number of returned keys
+func ListLimit(n uint) ListOption {
+	return func(o *ListOptions) {
+		o.Limit = n
 	}
 }
 
-// ListOffset starts returning responses from o. Use in conjunction with Limit for pagination.
-func ListOffset(o uint) ListOption {
-	return func(l *ListOptions) {
-		l.Offset = o
+// ListOffset use with Limit for pagination
+func ListOffset(n uint) ListOption {
+	return func(o *ListOptions) {
+		o.Offset = n
 	}
 }
 
-// ExistsOption specifies Exists call options
-type ExistsOption func(*ExistsOptions)
+// ListNamespace pass namespace to list options
+func ListNamespace(ns string) ListOption {
+	return func(o *ListOptions) {
+		o.Namespace = ns
+	}
+}
 
 // ExistsOptions holds options for Exists method
 type ExistsOptions struct {
@@ -312,6 +311,9 @@ type ExistsOptions struct {
 	Namespace string
 }
 
+// ExistsOption specifies Exists call options
+type ExistsOption func(*ExistsOptions)
+
 // NewExistsOptions helper for Exists method
 func NewExistsOptions(opts ...ExistsOption) ExistsOptions {
 	options := ExistsOptions{
@@ -322,3 +324,24 @@ func NewExistsOptions(opts ...ExistsOption) ExistsOptions {
 	}
 	return options
 }
+
+// ExistsContext pass context.Context to exist options
+func ExistsContext(ctx context.Context) ExistsOption {
+	return func(o *ExistsOptions) {
+		o.Context = ctx
+	}
+}
+
+// ExistsNamespace pass namespace to exist options
+func ExistsNamespace(ns string) ExistsOption {
+	return func(o *ExistsOptions) {
+		o.Namespace = ns
+	}
+}
+
+// WrapStore adds a store Wrapper to a list of options passed into the store
+//func WrapStore(w Wrapper) Option {
+//	return func(o *Options) {
+//		o.Wrappers = append(o.Wrappers, w)
+//	}
+//}

store/store.go

@@ -5,8 +5,6 @@ package store
 import (
 	"context"
 	"errors"
-
-	"github.com/unistack-org/micro/v3/metadata"
 )
 
 var (
@@ -42,12 +40,3 @@ type Store interface {
 	// String returns the name of the implementation.
 	String() string
 }
-
-// Value is an item stored or retrieved from a Store
-// may be used in store implementations to provide metadata
-type Value struct {
-	// Data holds underline struct
-	Data interface{} `json:"data"`
-	// Metadata associated with data for indexing
-	Metadata metadata.Metadata `json:"metadata"`
-}

store/wrapper.go

@@ -0,0 +1,84 @@
+package store
+
+import (
+	"context"
+)
+
+// LogfFunc function used for Logf method
+//type LogfFunc func(ctx context.Context, level Level, msg string, args ...interface{})
+
+//type Wrapper interface {
+// Logf logs message with needed level
+//Logf(LogfFunc) LogfFunc
+//}
+
+type NamespaceStore struct {
+	s  Store
+	ns string
+}
+
+var (
+	_ Store = &NamespaceStore{}
+)
+
+func NewNamespaceStore(s Store, ns string) Store {
+	return &NamespaceStore{s: s, ns: ns}
+}
+
+func (w *NamespaceStore) Init(opts ...Option) error {
+	return w.s.Init(opts...)
+}
+
+func (w *NamespaceStore) Connect(ctx context.Context) error {
+	return w.s.Connect(ctx)
+}
+
+func (w *NamespaceStore) Disconnect(ctx context.Context) error {
+	return w.s.Disconnect(ctx)
+}
+
+func (w *NamespaceStore) Read(ctx context.Context, key string, val interface{}, opts ...ReadOption) error {
+	return w.s.Read(ctx, key, val, append(opts, ReadNamespace(w.ns))...)
+}
+
+func (w *NamespaceStore) Write(ctx context.Context, key string, val interface{}, opts ...WriteOption) error {
+	return w.s.Write(ctx, key, val, append(opts, WriteNamespace(w.ns))...)
+}
+
+func (w *NamespaceStore) Delete(ctx context.Context, key string, opts ...DeleteOption) error {
+	return w.s.Delete(ctx, key, append(opts, DeleteNamespace(w.ns))...)
+}
+
+func (w *NamespaceStore) Exists(ctx context.Context, key string, opts ...ExistsOption) error {
+	return w.s.Exists(ctx, key, append(opts, ExistsNamespace(w.ns))...)
+}
+
+func (w *NamespaceStore) List(ctx context.Context, opts ...ListOption) ([]string, error) {
+	return w.s.List(ctx, append(opts, ListNamespace(w.ns))...)
+}
+
+func (w *NamespaceStore) Options() Options {
+	return w.s.Options()
+}
+
+func (w *NamespaceStore) Name() string {
+	return w.s.Name()
+}
+
+func (w *NamespaceStore) String() string {
+	return w.s.String()
+}
+
+//type NamespaceWrapper struct{}
+
+//func NewNamespaceWrapper() Wrapper {
+//	return &NamespaceWrapper{}
+//}
+
+/*
+func (w *OmitWrapper) Logf(fn LogfFunc) LogfFunc {
+	return func(ctx context.Context, level Level, msg string, args ...interface{}) {
+		fn(ctx, level, msg, getArgs(args)...)
+	}
+}
+*/

sync/memory.go

@@ -6,8 +6,8 @@ import (
 )
 
 type memorySync struct {
-	options Options
 	locks   map[string]*memoryLock
+	options Options
 	mtx     gosync.RWMutex
 }
 

sync/sync.go

@@ -5,10 +5,8 @@ import (
 	"errors"
 )
 
-var (
-	// ErrLockTimeout error
-	ErrLockTimeout = errors.New("lock timeout")
-)
+// ErrLockTimeout error
+var ErrLockTimeout = errors.New("lock timeout")
 
 // Sync is an interface for distributed synchronization
 type Sync interface {

tracer/noop.go

@@ -38,7 +38,6 @@ type noopSpan struct {
 }
 
 func (s *noopSpan) Finish(opts ...SpanOption) {
-
 }
 
 func (s *noopSpan) Context() context.Context {
@@ -50,7 +49,6 @@ func (s *noopSpan) Tracer() Tracer {
 }
 
 func (s *noopSpan) AddEvent(name string, opts ...EventOption) {
-
 }
 
 func (s *noopSpan) SetName(name string) {
@@ -58,7 +56,6 @@ func (s *noopSpan) SetName(name string) {
 }
 
 func (s *noopSpan) SetLabels(labels ...Label) {
-
 }
 
 // NewTracer returns new memory tracer

tracer/options.go

@@ -2,13 +2,11 @@ package tracer
 
 import "github.com/unistack-org/micro/v3/logger"
 
-type SpanOptions struct {
-}
+type SpanOptions struct{}
 
 type SpanOption func(o *SpanOptions)
 
-type EventOptions struct {
-}
+type EventOptions struct{}
 
 type EventOption func(o *EventOptions)