meter: improve Gauge

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

.github/workflows/job_sync.yml

@@ -18,34 +18,76 @@ jobs:
         echo "machine git.unistack.org login vtolstov password ${{ secrets.TOKEN_GITEA }}" >> /root/.netrc
         echo "machine github.com login vtolstov password ${{ secrets.TOKEN_GITHUB }}" >> /root/.netrc
 
+    - name: check master
+      id: check_master
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/master | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/master | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
     - name: sync master
+      if: steps.check_master.outputs.sync_needed == 'true'
       run: |
         git clone --filter=blob:none --filter=tree:0 --branch master --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
         cd repo
         git remote add --no-tags --fetch --track master upstream https://github.com/${GITHUB_REPOSITORY}
-        git merge upstream/master
+        git pull --rebase upstream master
         git push upstream master --progress
         git push origin master --progress
         cd ../
         rm -rf repo
 
+    - name: check v3
+      id: check_v3
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/v3 | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/v3 | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
     - name: sync v3
+      if: steps.check_v3.outputs.sync_needed == 'true'
       run: |
         git clone --filter=blob:none --filter=tree:0 --branch v3 --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
         cd repo
         git remote add --no-tags --fetch --track v3 upstream https://github.com/${GITHUB_REPOSITORY}
-        git merge upstream/v3
+        git pull --rebase upstream v3
         git push upstream v3 --progress
         git push origin v3 --progress
         cd ../
         rm -rf repo
 
+    - name: check v4
+      id: check_v4
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/v4 | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/v4 | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
     - name: sync v4
+      if: steps.check_v4.outputs.sync_needed == 'true'
       run: |
         git clone --filter=blob:none --filter=tree:0 --branch v4 --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
         cd repo
         git remote add --no-tags --fetch --track v4 upstream https://github.com/${GITHUB_REPOSITORY}
-        git merge upstream/v4
+        git pull --rebase upstream v4
         git push upstream v4 --progress
         git push origin v4 --progress
         cd ../

README.md

@@ -1,5 +1,5 @@
 # Micro
-![Coverage](https://img.shields.io/badge/Coverage-33.6%25-yellow)
+![Coverage](https://img.shields.io/badge/Coverage-33.8%25-yellow)
 [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/go.unistack.org/micro/v4?tab=overview)
 [![Status](https://git.unistack.org/unistack-org/micro/actions/workflows/job_tests.yml/badge.svg?branch=v4)](https://git.unistack.org/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Av4+event%3Apush)

broker/broker.go

@@ -41,7 +41,7 @@ type Broker interface {
 	// Disconnect disconnect from broker
 	Disconnect(ctx context.Context) error
 	// NewMessage create new broker message to publish.
-	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error)
+	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error)
 	// Publish message to broker topic
 	Publish(ctx context.Context, topic string, messages ...Message) error
 	// Subscribe subscribes to topic message via handler

broker/context.go

@@ -42,9 +42,9 @@ func SetSubscribeOption(k, v interface{}) SubscribeOption {
 	}
 }
 
-// SetPublishOption returns a function to setup a context with given value
+// SetMessageOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
+func SetMessageOption(k, v interface{}) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}

broker/memory/memory.go

@@ -22,7 +22,7 @@ type Broker struct {
 	subscribers   map[string][]*Subscriber
 	addr          string
 	opts          broker.Options
-	sync.RWMutex
+	mu            sync.RWMutex
 	connected     bool
 }
 
@@ -32,7 +32,7 @@ type memoryMessage struct {
 	ctx   context.Context
 	body  []byte
 	hdr   metadata.Metadata
-	opts  broker.PublishOptions
+	opts  broker.MessageOptions
 }
 
 func (m *memoryMessage) Ack() error {
@@ -72,9 +72,9 @@ func (b *Broker) newCodec(ct string) (codec.Codec, error) {
 	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
 		ct = ct[:idx]
 	}
-	b.RLock()
+	b.mu.RLock()
 	c, ok := b.opts.Codecs[ct]
-	b.RUnlock()
+	b.mu.RUnlock()
 	if ok {
 		return c, nil
 	}
@@ -96,8 +96,8 @@ func (b *Broker) Connect(ctx context.Context) error {
 	default:
 	}
 
-	b.Lock()
+	b.mu.Lock()
-	defer b.Unlock()
+	defer b.mu.Unlock()
 
 	if b.connected {
 		return nil
@@ -126,8 +126,8 @@ func (b *Broker) Disconnect(ctx context.Context) error {
 	default:
 	}
 
-	b.Lock()
+	b.mu.Lock()
-	defer b.Unlock()
+	defer b.mu.Unlock()
 
 	if !b.connected {
 		return nil
@@ -157,8 +157,11 @@ func (b *Broker) Init(opts ...broker.Option) error {
 	return nil
 }
 
-func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.PublishOption) (broker.Message, error) {
+func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.MessageOption) (broker.Message, error) {
-	options := broker.NewPublishOptions(opts...)
+	options := broker.NewMessageOptions(opts...)
+	if options.ContentType == "" {
+		options.ContentType = b.opts.ContentType
+	}
 	m := &memoryMessage{ctx: ctx, hdr: hdr, opts: options}
 	c, err := b.newCodec(m.opts.ContentType)
 	if err == nil {
@@ -180,12 +183,12 @@ func (b *Broker) fnPublish(ctx context.Context, topic string, messages ...broker
 }
 
 func (b *Broker) publish(ctx context.Context, topic string, messages ...broker.Message) error {
-	b.RLock()
+	b.mu.RLock()
 	if !b.connected {
-		b.RUnlock()
+		b.mu.RUnlock()
 		return broker.ErrNotConnected
 	}
-	b.RUnlock()
+	b.mu.RUnlock()
 
 	select {
 	case <-ctx.Done():
@@ -193,9 +196,9 @@ func (b *Broker) publish(ctx context.Context, topic string, messages ...broker.M
 	default:
 	}
 
-	b.RLock()
+	b.mu.RLock()
 	subs, ok := b.subscribers[topic]
-	b.RUnlock()
+	b.mu.RUnlock()
 	if !ok {
 		return nil
 	}
@@ -252,12 +255,12 @@ func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interfac
 		return nil, err
 	}
 
-	b.RLock()
+	b.mu.RLock()
 	if !b.connected {
-		b.RUnlock()
+		b.mu.RUnlock()
 		return nil, broker.ErrNotConnected
 	}
-	b.RUnlock()
+	b.mu.RUnlock()
 
 	sid, err := id.New()
 	if err != nil {
@@ -275,13 +278,13 @@ func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interfac
 		ctx:     ctx,
 	}
 
-	b.Lock()
+	b.mu.Lock()
 	b.subscribers[topic] = append(b.subscribers[topic], sub)
-	b.Unlock()
+	b.mu.Unlock()
 
 	go func() {
 		<-sub.exit
-		b.Lock()
+		b.mu.Lock()
 		newSubscribers := make([]*Subscriber, 0, len(b.subscribers)-1)
 		for _, sb := range b.subscribers[topic] {
 			if sb.id == sub.id {
@@ -290,7 +293,7 @@ func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interfac
 			newSubscribers = append(newSubscribers, sb)
 		}
 		b.subscribers[topic] = newSubscribers
-		b.Unlock()
+		b.mu.Unlock()
 	}()
 
 	return sub, nil

broker/memory/memory_test.go

@@ -49,7 +49,7 @@ func TestMemoryBroker(t *testing.T) {
 				"id", fmt.Sprintf("%d", i),
 			),
 			[]byte(`"hello world"`),
-			broker.PublishContentType("application/octet-stream"),
+			broker.MessageContentType("application/octet-stream"),
 		)
 		if err != nil {
 			t.Fatal(err)

broker/noop.go

@@ -14,16 +14,16 @@ type NoopBroker struct {
 	funcPublish   FuncPublish
 	funcSubscribe FuncSubscribe
 	opts          Options
-	sync.RWMutex
+	mu            sync.RWMutex
 }
 
 func (b *NoopBroker) newCodec(ct string) (codec.Codec, error) {
 	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
 		ct = ct[:idx]
 	}
-	b.RLock()
+	b.mu.RLock()
 	c, ok := b.opts.Codecs[ct]
-	b.RUnlock()
+	b.mu.RUnlock()
 	if ok {
 		return c, nil
 	}
@@ -99,7 +99,7 @@ type noopMessage struct {
 	ctx  context.Context
 	body []byte
 	hdr  metadata.Metadata
-	opts PublishOptions
+	opts MessageOptions
 }
 
 func (m *noopMessage) Ack() error {
@@ -126,8 +126,11 @@ func (m *noopMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
 	return m.c.Unmarshal(m.body, dst)
 }
 
-func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error) {
+func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error) {
-	options := NewPublishOptions(opts...)
+	options := NewMessageOptions(opts...)
+	if options.ContentType == "" {
+		options.ContentType = b.opts.ContentType
+	}
 	m := &noopMessage{ctx: ctx, hdr: hdr, opts: options}
 	c, err := b.newCodec(m.opts.ContentType)
 	if err == nil {

broker/options.go

@@ -45,6 +45,9 @@ type Options struct {
 
 	// GracefulTimeout contains time to wait to finish in flight requests
 	GracefulTimeout time.Duration
+
+	// ContentType will be used if no content-type set when creating message
+	ContentType string
 }
 
 // NewOptions create new Options
@@ -57,14 +60,19 @@ func NewOptions(opts ...Option) Options {
 		Codecs:          make(map[string]codec.Codec),
 		Tracer:          tracer.DefaultTracer,
 		GracefulTimeout: DefaultGracefulTimeout,
+		ContentType:     DefaultContentType,
 	}
 
 	for _, o := range opts {
 		o(&options)
 	}
+
 	return options
 }
 
+// DefaultContentType is the default content-type if not specified
+var DefaultContentType = ""
+
 // Context sets the context option
 func Context(ctx context.Context) Option {
 	return func(o *Options) {
@@ -72,8 +80,15 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// PublishOptions struct
+// ContentType used by default if not specified
-type PublishOptions struct {
+func ContentType(ct string) Option {
+	return func(o *Options) {
+		o.ContentType = ct
+	}
+}
+
+// MessageOptions struct
+type MessageOptions struct {
 	// ContentType for message body
 	ContentType string
 	// BodyOnly flag says the message contains raw body bytes and don't need
@@ -83,9 +98,9 @@ type PublishOptions struct {
 	Context context.Context
 }
 
-// NewPublishOptions creates PublishOptions struct
+// NewMessageOptions creates MessageOptions struct
-func NewPublishOptions(opts ...PublishOption) PublishOptions {
+func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := PublishOptions{
+	options := MessageOptions{
 		Context: context.Background(),
 	}
 	for _, o := range opts {
@@ -113,19 +128,19 @@ type SubscribeOptions struct {
 // Option func
 type Option func(*Options)
 
-// PublishOption func
+// MessageOption func
-type PublishOption func(*PublishOptions)
+type MessageOption func(*MessageOptions)
 
-// PublishContentType sets message content-type that used to Marshal
+// MessageContentType sets message content-type that used to Marshal
-func PublishContentType(ct string) PublishOption {
+func MessageContentType(ct string) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		o.ContentType = ct
 	}
 }
 
-// PublishBodyOnly publish only body of the message
+// MessageBodyOnly publish only body of the message
-func PublishBodyOnly(b bool) PublishOption {
+func MessageBodyOnly(b bool) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		o.BodyOnly = b
 	}
 }

cluster/hasql/cluster.go

@@ -0,0 +1,235 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"reflect"
+	"unsafe"
+
+	"golang.yandex/hasql/v2"
+)
+
+func newSQLRowError() *sql.Row {
+	row := &sql.Row{}
+	t := reflect.TypeOf(row).Elem()
+	field, _ := t.FieldByName("err")
+	rowPtr := unsafe.Pointer(row)
+	errFieldPtr := unsafe.Pointer(uintptr(rowPtr) + field.Offset)
+	errPtr := (*error)(errFieldPtr)
+	*errPtr = ErrorNoAliveNodes
+	return row
+}
+
+type ClusterQuerier interface {
+	Querier
+	WaitForNodes(ctx context.Context, criterion ...hasql.NodeStateCriterion) error
+}
+
+type Cluster struct {
+	hasql   *hasql.Cluster[Querier]
+	options ClusterOptions
+}
+
+// NewCluster returns [Querier] that provides cluster of nodes
+func NewCluster[T Querier](opts ...ClusterOption) (ClusterQuerier, error) {
+	options := ClusterOptions{Context: context.Background()}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	if options.NodeChecker == nil {
+		return nil, ErrClusterChecker
+	}
+	if options.NodeDiscoverer == nil {
+		return nil, ErrClusterDiscoverer
+	}
+	if options.NodePicker == nil {
+		return nil, ErrClusterPicker
+	}
+
+	if options.Retries < 1 {
+		options.Retries = 1
+	}
+
+	if options.NodeStateCriterion == 0 {
+		options.NodeStateCriterion = hasql.Primary
+	}
+
+	options.Options = append(options.Options, hasql.WithNodePicker(options.NodePicker))
+	if p, ok := options.NodePicker.(*CustomPicker[Querier]); ok {
+		p.opts.Priority = options.NodePriority
+	}
+
+	c, err := hasql.NewCluster(
+		options.NodeDiscoverer,
+		options.NodeChecker,
+		options.Options...,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Cluster{hasql: c, options: options}, nil
+}
+
+func (c *Cluster) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
+	var tx *sql.Tx
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if tx, err = n.DB().BeginTx(ctx, opts); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if tx == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return tx, err
+}
+
+func (c *Cluster) Close() error {
+	return c.hasql.Close()
+}
+
+func (c *Cluster) Conn(ctx context.Context) (*sql.Conn, error) {
+	var conn *sql.Conn
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if conn, err = n.DB().Conn(ctx); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if conn == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return conn, err
+}
+
+func (c *Cluster) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	var res sql.Result
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().ExecContext(ctx, query, args...); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	var res *sql.Stmt
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().PrepareContext(ctx, query); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	var res *sql.Rows
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().QueryContext(ctx, query); err != nil && err != sql.ErrNoRows && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	var res *sql.Row
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			res = n.DB().QueryRowContext(ctx, query, args...)
+			if res.Err() == nil {
+				return false
+			} else if res.Err() != nil && retries >= c.options.Retries {
+				return false
+			}
+		}
+		return true
+	})
+
+	if res == nil {
+		res = newSQLRowError()
+	}
+
+	return res
+}
+
+func (c *Cluster) PingContext(ctx context.Context) error {
+	var err error
+	var ok bool
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		ok = true
+		for ; retries < c.options.Retries; retries++ {
+			if err = n.DB().PingContext(ctx); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if !ok {
+		err = ErrorNoAliveNodes
+	}
+
+	return err
+}
+
+func (c *Cluster) WaitForNodes(ctx context.Context, criterions ...hasql.NodeStateCriterion) error {
+	for _, criterion := range criterions {
+		if _, err := c.hasql.WaitForNode(ctx, criterion); err != nil {
+			return err
+		}
+	}
+	return nil
+}

cluster/hasql/cluster_test.go

@@ -0,0 +1,171 @@
+package sql
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"golang.yandex/hasql/v2"
+)
+
+func TestNewCluster(t *testing.T) {
+	dbMaster, dbMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbMaster.Close()
+	dbMasterMock.MatchExpectationsInOrder(false)
+
+	dbMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(1, 0)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("master-dc1"))
+
+	dbDRMaster, dbDRMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbDRMaster.Close()
+	dbDRMasterMock.MatchExpectationsInOrder(false)
+
+	dbDRMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 40)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster1-dc2"))
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster"))
+
+	dbSlaveDC1, dbSlaveDC1Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC1.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC1Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	dbSlaveDC2, dbSlaveDC2Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC2.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC2Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC2Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	tctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
+	defer cancel()
+
+	c, err := NewCluster[Querier](
+		WithClusterContext(tctx),
+		WithClusterNodeChecker(hasql.PostgreSQLChecker),
+		WithClusterNodePicker(NewCustomPicker[Querier](
+			CustomPickerMaxLag(100),
+		)),
+		WithClusterNodes(
+			ClusterNode{"slave-dc1", dbSlaveDC1, 1},
+			ClusterNode{"master-dc1", dbMaster, 1},
+			ClusterNode{"slave-dc2", dbSlaveDC2, 2},
+			ClusterNode{"drmaster1-dc2", dbDRMaster, 0},
+		),
+		WithClusterOptions(
+			hasql.WithUpdateInterval[Querier](2*time.Second),
+			hasql.WithUpdateTimeout[Querier](1*time.Second),
+		),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	if err = c.WaitForNodes(tctx, hasql.Primary, hasql.Standby); err != nil {
+		t.Fatal(err)
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	node1Name := ""
+	fmt.Printf("check for Standby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.Standby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node1Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node1Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node1Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	node2Name := ""
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node2Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node2Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node2Name)
+	}
+
+	node3Name := ""
+	fmt.Printf("check for PreferPrimary\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferPrimary), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node3Name); err != nil {
+		t.Fatal(err)
+	} else if "master-dc1" != node3Name {
+		t.Fatalf("invalid node name %s != %s", "master-dc1", node3Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`.*`).WillReturnRows(sqlmock.NewRows([]string{"role"}).RowError(1, fmt.Errorf("row error")))
+
+	time.Sleep(2 * time.Second)
+
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() == nil {
+		t.Fatal("must return error")
+	}
+
+	if dbMasterErr := dbMasterMock.ExpectationsWereMet(); dbMasterErr != nil {
+		t.Error(dbMasterErr)
+	}
+}

cluster/hasql/db.go

@@ -0,0 +1,25 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+)
+
+type Querier interface {
+	// Basic connection methods
+	PingContext(ctx context.Context) error
+	Close() error
+
+	// Query methods with context
+	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
+	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
+
+	// Prepared statements with context
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+
+	// Transaction management with context
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
+
+	Conn(ctx context.Context) (*sql.Conn, error)
+}

cluster/hasql/driver.go

@@ -0,0 +1,295 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"io"
+	"sync"
+	"time"
+)
+
+// OpenDBWithCluster creates a [*sql.DB] that uses the [ClusterQuerier]
+func OpenDBWithCluster(db ClusterQuerier) (*sql.DB, error) {
+	driver := NewClusterDriver(db)
+	connector, err := driver.OpenConnector("")
+	if err != nil {
+		return nil, err
+	}
+	return sql.OpenDB(connector), nil
+}
+
+// ClusterDriver implements [driver.Driver] and driver.Connector for an existing [Querier]
+type ClusterDriver struct {
+	db ClusterQuerier
+}
+
+// NewClusterDriver creates a new [driver.Driver] that uses an existing [ClusterQuerier]
+func NewClusterDriver(db ClusterQuerier) *ClusterDriver {
+	return &ClusterDriver{db: db}
+}
+
+// Open implements [driver.Driver.Open]
+func (d *ClusterDriver) Open(name string) (driver.Conn, error) {
+	return d.Connect(context.Background())
+}
+
+// OpenConnector implements [driver.DriverContext.OpenConnector]
+func (d *ClusterDriver) OpenConnector(name string) (driver.Connector, error) {
+	return d, nil
+}
+
+// Connect implements [driver.Connector.Connect]
+func (d *ClusterDriver) Connect(ctx context.Context) (driver.Conn, error) {
+	conn, err := d.db.Conn(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return &dbConn{conn: conn}, nil
+}
+
+// Driver implements [driver.Connector.Driver]
+func (d *ClusterDriver) Driver() driver.Driver {
+	return d
+}
+
+// dbConn implements driver.Conn with both context and legacy methods
+type dbConn struct {
+	conn *sql.Conn
+	mu   sync.Mutex
+}
+
+// Prepare implements [driver.Conn.Prepare] (legacy method)
+func (c *dbConn) Prepare(query string) (driver.Stmt, error) {
+	return c.PrepareContext(context.Background(), query)
+}
+
+// PrepareContext implements [driver.ConnPrepareContext.PrepareContext]
+func (c *dbConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	stmt, err := c.conn.PrepareContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbStmt{stmt: stmt}, nil
+}
+
+// Exec implements [driver.Execer.Exec] (legacy method)
+func (c *dbConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return c.ExecContext(context.Background(), query, namedArgs)
+}
+
+// ExecContext implements [driver.ExecerContext.ExecContext]
+func (c *dbConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Convert driver.NamedValue to any
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	return c.conn.ExecContext(ctx, query, interfaceArgs...)
+}
+
+// Query implements [driver.Queryer.Query] (legacy method)
+func (c *dbConn) Query(query string, args []driver.Value) (driver.Rows, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return c.QueryContext(context.Background(), query, namedArgs)
+}
+
+// QueryContext implements [driver.QueryerContext.QueryContext]
+func (c *dbConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Convert driver.NamedValue to any
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	rows, err := c.conn.QueryContext(ctx, query, interfaceArgs...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbRows{rows: rows}, nil
+}
+
+// Begin implements [driver.Conn.Begin] (legacy method)
+func (c *dbConn) Begin() (driver.Tx, error) {
+	return c.BeginTx(context.Background(), driver.TxOptions{})
+}
+
+// BeginTx implements [driver.ConnBeginTx.BeginTx]
+func (c *dbConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	sqlOpts := &sql.TxOptions{
+		Isolation: sql.IsolationLevel(opts.Isolation),
+		ReadOnly:  opts.ReadOnly,
+	}
+
+	tx, err := c.conn.BeginTx(ctx, sqlOpts)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbTx{tx: tx}, nil
+}
+
+// Ping implements [driver.Pinger.Ping]
+func (c *dbConn) Ping(ctx context.Context) error {
+	return c.conn.PingContext(ctx)
+}
+
+// Close implements [driver.Conn.Close]
+func (c *dbConn) Close() error {
+	return c.conn.Close()
+}
+
+// IsValid implements [driver.Validator.IsValid]
+func (c *dbConn) IsValid() bool {
+	// Ping with a short timeout to check if the connection is still valid
+	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel()
+
+	return c.conn.PingContext(ctx) == nil
+}
+
+// dbStmt implements [driver.Stmt] with both context and legacy methods
+type dbStmt struct {
+	stmt *sql.Stmt
+	mu   sync.Mutex
+}
+
+// Close implements [driver.Stmt.Close]
+func (s *dbStmt) Close() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.stmt.Close()
+}
+
+// Close implements [driver.Stmt.NumInput]
+func (s *dbStmt) NumInput() int {
+	return -1 // Number of parameters is unknown
+}
+
+// Exec implements [driver.Stmt.Exec] (legacy method)
+func (s *dbStmt) Exec(args []driver.Value) (driver.Result, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return s.ExecContext(context.Background(), namedArgs)
+}
+
+// ExecContext implements [driver.StmtExecContext.ExecContext]
+func (s *dbStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+	return s.stmt.ExecContext(ctx, interfaceArgs...)
+}
+
+// Query implements [driver.Stmt.Query] (legacy method)
+func (s *dbStmt) Query(args []driver.Value) (driver.Rows, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return s.QueryContext(context.Background(), namedArgs)
+}
+
+// QueryContext implements [driver.StmtQueryContext.QueryContext]
+func (s *dbStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	rows, err := s.stmt.QueryContext(ctx, interfaceArgs...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbRows{rows: rows}, nil
+}
+
+// dbRows implements [driver.Rows]
+type dbRows struct {
+	rows *sql.Rows
+}
+
+// Columns implements [driver.Rows.Columns]
+func (r *dbRows) Columns() []string {
+	cols, err := r.rows.Columns()
+	if err != nil {
+		// This shouldn't happen if the query was successful
+		return []string{}
+	}
+	return cols
+}
+
+// Close implements [driver.Rows.Close]
+func (r *dbRows) Close() error {
+	return r.rows.Close()
+}
+
+// Next implements [driver.Rows.Next]
+func (r *dbRows) Next(dest []driver.Value) error {
+	if !r.rows.Next() {
+		if err := r.rows.Err(); err != nil {
+			return err
+		}
+		return io.EOF
+	}
+
+	// Create a slice of interfaces to scan into
+	scanArgs := make([]any, len(dest))
+	for i := range scanArgs {
+		scanArgs[i] = &dest[i]
+	}
+
+	return r.rows.Scan(scanArgs...)
+}
+
+// dbTx implements [driver.Tx]
+type dbTx struct {
+	tx *sql.Tx
+	mu sync.Mutex
+}
+
+// Commit implements [driver.Tx.Commit]
+func (t *dbTx) Commit() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.tx.Commit()
+}
+
+// Rollback implements [driver.Tx.Rollback]
+func (t *dbTx) Rollback() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.tx.Rollback()
+}

cluster/hasql/driver_test.go

@@ -0,0 +1,141 @@
+package sql
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"golang.yandex/hasql/v2"
+)
+
+func TestDriver(t *testing.T) {
+	dbMaster, dbMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbMaster.Close()
+	dbMasterMock.MatchExpectationsInOrder(false)
+
+	dbMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(1, 0)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("master-dc1"))
+
+	dbDRMaster, dbDRMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbDRMaster.Close()
+	dbDRMasterMock.MatchExpectationsInOrder(false)
+
+	dbDRMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 40)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster1-dc2"))
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster"))
+
+	dbSlaveDC1, dbSlaveDC1Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC1.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC1Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	dbSlaveDC2, dbSlaveDC2Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC2.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC2Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC2Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	tctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
+	defer cancel()
+
+	c, err := NewCluster[Querier](
+		WithClusterContext(tctx),
+		WithClusterNodeChecker(hasql.PostgreSQLChecker),
+		WithClusterNodePicker(NewCustomPicker[Querier](
+			CustomPickerMaxLag(100),
+		)),
+		WithClusterNodes(
+			ClusterNode{"slave-dc1", dbSlaveDC1, 1},
+			ClusterNode{"master-dc1", dbMaster, 1},
+			ClusterNode{"slave-dc2", dbSlaveDC2, 2},
+			ClusterNode{"drmaster1-dc2", dbDRMaster, 0},
+		),
+		WithClusterOptions(
+			hasql.WithUpdateInterval[Querier](2*time.Second),
+			hasql.WithUpdateTimeout[Querier](1*time.Second),
+		),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	if err = c.WaitForNodes(tctx, hasql.Primary, hasql.Standby); err != nil {
+		t.Fatal(err)
+	}
+
+	db, err := OpenDBWithCluster(c)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Use context methods
+	row := db.QueryRowContext(NodeStateCriterion(t.Context(), hasql.Primary), "SELECT node_name as name")
+	if err = row.Err(); err != nil {
+		t.Fatal(err)
+	}
+
+	nodeName := ""
+	if err = row.Scan(&nodeName); err != nil {
+		t.Fatal(err)
+	}
+
+	if nodeName != "master-dc1" {
+		t.Fatalf("invalid node_name %s != %s", "master-dc1", nodeName)
+	}
+}

cluster/hasql/error.go

@@ -0,0 +1,10 @@
+package sql
+
+import "errors"
+
+var (
+	ErrClusterChecker    = errors.New("cluster node checker required")
+	ErrClusterDiscoverer = errors.New("cluster node discoverer required")
+	ErrClusterPicker     = errors.New("cluster node picker required")
+	ErrorNoAliveNodes    = errors.New("cluster no alive nodes")
+)

cluster/hasql/options.go

@@ -0,0 +1,110 @@
+package sql
+
+import (
+	"context"
+	"math"
+
+	"golang.yandex/hasql/v2"
+)
+
+// ClusterOptions contains cluster specific options
+type ClusterOptions struct {
+	NodeChecker        hasql.NodeChecker
+	NodePicker         hasql.NodePicker[Querier]
+	NodeDiscoverer     hasql.NodeDiscoverer[Querier]
+	Options            []hasql.ClusterOpt[Querier]
+	Context            context.Context
+	Retries            int
+	NodePriority       map[string]int32
+	NodeStateCriterion hasql.NodeStateCriterion
+}
+
+// ClusterOption apply cluster options to ClusterOptions
+type ClusterOption func(*ClusterOptions)
+
+// WithClusterNodeChecker pass hasql.NodeChecker to cluster options
+func WithClusterNodeChecker(c hasql.NodeChecker) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeChecker = c
+	}
+}
+
+// WithClusterNodePicker pass hasql.NodePicker to cluster options
+func WithClusterNodePicker(p hasql.NodePicker[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodePicker = p
+	}
+}
+
+// WithClusterNodeDiscoverer pass hasql.NodeDiscoverer to cluster options
+func WithClusterNodeDiscoverer(d hasql.NodeDiscoverer[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeDiscoverer = d
+	}
+}
+
+// WithRetries retry count on other nodes in case of error
+func WithRetries(n int) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Retries = n
+	}
+}
+
+// WithClusterContext pass context.Context to cluster options and used for checks
+func WithClusterContext(ctx context.Context) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Context = ctx
+	}
+}
+
+// WithClusterOptions pass hasql.ClusterOpt
+func WithClusterOptions(opts ...hasql.ClusterOpt[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Options = append(o.Options, opts...)
+	}
+}
+
+// WithClusterNodeStateCriterion pass default hasql.NodeStateCriterion
+func WithClusterNodeStateCriterion(c hasql.NodeStateCriterion) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeStateCriterion = c
+	}
+}
+
+type ClusterNode struct {
+	Name     string
+	DB       Querier
+	Priority int32
+}
+
+// WithClusterNodes create cluster with static NodeDiscoverer
+func WithClusterNodes(cns ...ClusterNode) ClusterOption {
+	return func(o *ClusterOptions) {
+		nodes := make([]*hasql.Node[Querier], 0, len(cns))
+		if o.NodePriority == nil {
+			o.NodePriority = make(map[string]int32, len(cns))
+		}
+		for _, cn := range cns {
+			nodes = append(nodes, hasql.NewNode(cn.Name, cn.DB))
+			if cn.Priority == 0 {
+				cn.Priority = math.MaxInt32
+			}
+			o.NodePriority[cn.Name] = cn.Priority
+		}
+		o.NodeDiscoverer = hasql.NewStaticNodeDiscoverer(nodes...)
+	}
+}
+
+type nodeStateCriterionKey struct{}
+
+// NodeStateCriterion inject hasql.NodeStateCriterion to context
+func NodeStateCriterion(ctx context.Context, c hasql.NodeStateCriterion) context.Context {
+	return context.WithValue(ctx, nodeStateCriterionKey{}, c)
+}
+
+func (c *Cluster) getNodeStateCriterion(ctx context.Context) hasql.NodeStateCriterion {
+	if v, ok := ctx.Value(nodeStateCriterionKey{}).(hasql.NodeStateCriterion); ok {
+		return v
+	}
+	return c.options.NodeStateCriterion
+}

cluster/hasql/picker.go

@@ -0,0 +1,113 @@
+package sql
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	"golang.yandex/hasql/v2"
+)
+
+// compile time guard
+var _ hasql.NodePicker[Querier] = (*CustomPicker[Querier])(nil)
+
+// CustomPickerOptions holds options to pick nodes
+type CustomPickerOptions struct {
+	MaxLag   int
+	Priority map[string]int32
+	Retries  int
+}
+
+// CustomPickerOption func apply option to CustomPickerOptions
+type CustomPickerOption func(*CustomPickerOptions)
+
+// CustomPickerMaxLag specifies max lag for which node can be used
+func CustomPickerMaxLag(n int) CustomPickerOption {
+	return func(o *CustomPickerOptions) {
+		o.MaxLag = n
+	}
+}
+
+// NewCustomPicker creates new node picker
+func NewCustomPicker[T Querier](opts ...CustomPickerOption) *CustomPicker[Querier] {
+	options := CustomPickerOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &CustomPicker[Querier]{opts: options}
+}
+
+// CustomPicker holds node picker options
+type CustomPicker[T Querier] struct {
+	opts CustomPickerOptions
+}
+
+// PickNode used to return specific node
+func (p *CustomPicker[T]) PickNode(cnodes []hasql.CheckedNode[T]) hasql.CheckedNode[T] {
+	for _, n := range cnodes {
+		fmt.Printf("node %s\n", n.Node.String())
+	}
+	return cnodes[0]
+}
+
+func (p *CustomPicker[T]) getPriority(nodeName string) int32 {
+	if prio, ok := p.opts.Priority[nodeName]; ok {
+		return prio
+	}
+	return math.MaxInt32 // Default to lowest priority
+}
+
+// CompareNodes used to sort nodes
+func (p *CustomPicker[T]) CompareNodes(a, b hasql.CheckedNode[T]) int {
+	// Get replication lag values
+	aLag := a.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+	bLag := b.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+
+	// First check that lag lower then MaxLag
+	if aLag > p.opts.MaxLag && bLag > p.opts.MaxLag {
+		return 0 // both are equal
+	}
+
+	// If one node exceeds MaxLag and the other doesn't, prefer the one that doesn't
+	if aLag > p.opts.MaxLag {
+		return 1 // b is better
+	}
+	if bLag > p.opts.MaxLag {
+		return -1 // a is better
+	}
+
+	// Get node priorities
+	aPrio := p.getPriority(a.Node.String())
+	bPrio := p.getPriority(b.Node.String())
+
+	// if both priority equals
+	if aPrio == bPrio {
+		// First compare by replication lag
+		if aLag < bLag {
+			return -1
+		}
+		if aLag > bLag {
+			return 1
+		}
+		// If replication lag is equal, compare by latency
+		aLatency := a.Info.(interface{ Latency() time.Duration }).Latency()
+		bLatency := b.Info.(interface{ Latency() time.Duration }).Latency()
+
+		if aLatency < bLatency {
+			return -1
+		}
+		if aLatency > bLatency {
+			return 1
+		}
+
+		// If lag and latency is equal
+		return 0
+	}
+
+	// If priorities are different, prefer the node with lower priority value
+	if aPrio < bPrio {
+		return -1
+	}
+
+	return 1
+}

codec/codec.go

@@ -3,8 +3,6 @@ package codec
 
 import (
 	"errors"
-
-	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -68,10 +66,10 @@ func (m *RawMessage) MarshalYAML() ([]byte, error) {
 }
 
 // UnmarshalYAML sets *m to a copy of data.
-func (m *RawMessage) UnmarshalYAML(n *yaml.Node) error {
+func (m *RawMessage) UnmarshalYAML(data []byte) error {
 	if m == nil {
 		return errors.New("RawMessage UnmarshalYAML on nil pointer")
 	}
-	*m = append((*m)[0:0], []byte(n.Value)...)
+	*m = append((*m)[0:0], data...)
 	return nil
 }

codec/frame.go

@@ -1,7 +1,5 @@
 package codec
 
-import "gopkg.in/yaml.v3"
-
 // Frame gives us the ability to define raw data to send over the pipes
 type Frame struct {
 	Data []byte
@@ -28,8 +26,8 @@ func (m *Frame) MarshalYAML() ([]byte, error) {
 }
 
 // UnmarshalYAML set frame data
-func (m *Frame) UnmarshalYAML(n *yaml.Node) error {
+func (m *Frame) UnmarshalYAML(data []byte) error {
-	m.Data = []byte(n.Value)
+	m.Data = append((m.Data)[0:0], data...)
 	return nil
 }
 

go.mod

@@ -1,12 +1,12 @@
 module go.unistack.org/micro/v4
 
-go 1.22.0
+go 1.24
 
 require (
 	dario.cat/mergo v1.0.1
 	github.com/DATA-DOG/go-sqlmock v1.5.2
 	github.com/KimMachineGun/automemlimit v0.7.0
-	github.com/ash3in/uuidv8 v1.2.0
+	github.com/goccy/go-yaml v1.17.1
 	github.com/google/uuid v1.6.0
 	github.com/matoous/go-nanoid v1.5.1
 	github.com/patrickmn/go-cache v2.1.0+incompatible
@@ -17,9 +17,9 @@ require (
 	go.uber.org/automaxprocs v1.6.0
 	go.unistack.org/micro-proto/v4 v4.1.0
 	golang.org/x/sync v0.10.0
+	golang.yandex/hasql/v2 v2.1.0
 	google.golang.org/grpc v1.69.4
 	google.golang.org/protobuf v1.36.3
-	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
@@ -31,4 +31,5 @@ require (
 	golang.org/x/sys v0.29.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -4,12 +4,12 @@ github.com/DATA-DOG/go-sqlmock v1.5.2 h1:OcvFkGmslmlZibjAjaHm3L//6LiuBgolP7Oputl
 github.com/DATA-DOG/go-sqlmock v1.5.2/go.mod h1:88MAG/4G7SMwSE3CeA0ZKzrT5CiOU3OJ+JlNzwDqpNU=
 github.com/KimMachineGun/automemlimit v0.7.0 h1:7G06p/dMSf7G8E6oq+f2uOPuVncFyIlDI/pBWK49u88=
 github.com/KimMachineGun/automemlimit v0.7.0/go.mod h1:QZxpHaGOQoYvFhv/r4u3U0JTC2ZcOwbSr11UZF46UBM=
-github.com/ash3in/uuidv8 v1.2.0 h1:2oogGdtCPwaVtyvPPGin4TfZLtOGE5F+W++E880G6SI=
-github.com/ash3in/uuidv8 v1.2.0/go.mod h1:BnU0wJBxnzdEKmVg4xckBkD+VZuecTFTUP3M0dWgyY4=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
+github.com/goccy/go-yaml v1.17.1 h1:LI34wktB2xEE3ONG/2Ar54+/HJVBriAGJ55PHls4YuY=
+github.com/goccy/go-yaml v1.17.1/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
@@ -56,6 +56,8 @@ golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
 golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+golang.yandex/hasql/v2 v2.1.0 h1:7CaFFWeHoK5TvA+QvZzlKHlIN5sqNpqM8NSrXskZD/k=
+golang.yandex/hasql/v2 v2.1.0/go.mod h1:3Au1AxuJDCTXmS117BpbI6e+70kGWeyLR1qJAH6HdtA=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 h1:Z7FRVJPSMaHQxD0uXU8WdgFh8PseLM8Q8NzhnpMrBhQ=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484/go.mod h1:lcTa1sDdWEIHMWlITnIczmw5w60CF9ffkb8Z+DVmmjA=
 google.golang.org/grpc v1.69.4 h1:MF5TftSMkd8GLw/m0KM6V8CMOCY6NZ1NQDPGFgbTt4A=

hooks/sql/stats.go

@@ -3,6 +3,7 @@ package sql
 import (
 	"context"
 	"database/sql"
+	"sync"
 	"time"
 )
 
@@ -11,31 +12,84 @@ type Statser interface {
 }
 
 func NewStatsMeter(ctx context.Context, db Statser, opts ...Option) {
-	options := NewOptions(opts...)
-
-	go func() {
-		ticker := time.NewTicker(options.MeterStatsInterval)
-		defer ticker.Stop()
-
-		for {
-			select {
-			case <-ctx.Done():
-				return
-			case <-ticker.C:
 	if db == nil {
 		return
 	}
+
+	options := NewOptions(opts...)
+
+	var (
+		statsMu                                                     sync.Mutex
+		lastUpdated                                                 time.Time
+		maxOpenConnections, openConnections, inUse, idle, waitCount float64
+		maxIdleClosed, maxIdleTimeClosed, maxLifetimeClosed         float64
+		waitDuration                                                float64
+	)
+
+	updateFn := func() {
+		statsMu.Lock()
+		defer statsMu.Unlock()
+
+		if time.Since(lastUpdated) < options.MeterStatsInterval {
+			return
+		}
+
 		stats := db.Stats()
-				options.Meter.Counter(MaxOpenConnections).Set(uint64(stats.MaxOpenConnections))
+		maxOpenConnections = float64(stats.MaxOpenConnections)
-				options.Meter.Counter(OpenConnections).Set(uint64(stats.OpenConnections))
+		openConnections = float64(stats.OpenConnections)
-				options.Meter.Counter(InuseConnections).Set(uint64(stats.InUse))
+		inUse = float64(stats.InUse)
-				options.Meter.Counter(IdleConnections).Set(uint64(stats.Idle))
+		idle = float64(stats.Idle)
-				options.Meter.Counter(WaitConnections).Set(uint64(stats.WaitCount))
+		waitCount = float64(stats.WaitCount)
-				options.Meter.FloatCounter(BlockedSeconds).Set(stats.WaitDuration.Seconds())
+		maxIdleClosed = float64(stats.MaxIdleClosed)
-				options.Meter.Counter(MaxIdleClosed).Set(uint64(stats.MaxIdleClosed))
+		maxIdleTimeClosed = float64(stats.MaxIdleTimeClosed)
-				options.Meter.Counter(MaxIdletimeClosed).Set(uint64(stats.MaxIdleTimeClosed))
+		maxLifetimeClosed = float64(stats.MaxLifetimeClosed)
-				options.Meter.Counter(MaxLifetimeClosed).Set(uint64(stats.MaxLifetimeClosed))
+		waitDuration = float64(stats.WaitDuration.Seconds())
+
+		lastUpdated = time.Now()
 	}
-		}
+
-	}()
+	options.Meter.Gauge(MaxOpenConnections, func() float64 {
+		updateFn()
+		return maxOpenConnections
+	})
+
+	options.Meter.Gauge(OpenConnections, func() float64 {
+		updateFn()
+		return openConnections
+	})
+
+	options.Meter.Gauge(InuseConnections, func() float64 {
+		updateFn()
+		return inUse
+	})
+
+	options.Meter.Gauge(IdleConnections, func() float64 {
+		updateFn()
+		return idle
+	})
+
+	options.Meter.Gauge(WaitConnections, func() float64 {
+		updateFn()
+		return waitCount
+	})
+
+	options.Meter.Gauge(BlockedSeconds, func() float64 {
+		updateFn()
+		return waitDuration
+	})
+
+	options.Meter.Gauge(MaxIdleClosed, func() float64 {
+		updateFn()
+		return maxIdleClosed
+	})
+
+	options.Meter.Gauge(MaxIdletimeClosed, func() float64 {
+		updateFn()
+		return maxIdleTimeClosed
+	})
+
+	options.Meter.Gauge(MaxLifetimeClosed, func() float64 {
+		updateFn()
+		return maxLifetimeClosed
+	})
 }

logger/level.go

@@ -4,18 +4,20 @@ package logger
 type Level int8
 
 const (
-	// TraceLevel level usually used to find bugs, very verbose
+	// TraceLevel usually used to find bugs, very verbose
 	TraceLevel Level = iota - 2
-	// DebugLevel level used only when enabled debugging
+	// DebugLevel used only when enabled debugging
 	DebugLevel
-	// InfoLevel level used for general info about what's going on inside the application
+	// InfoLevel used for general info about what's going on inside the application
 	InfoLevel
-	// WarnLevel level used for non-critical entries
+	// WarnLevel used for non-critical entries
 	WarnLevel
-	// ErrorLevel level used for errors that should definitely be noted
+	// ErrorLevel used for errors that should definitely be noted
 	ErrorLevel
-	// FatalLevel level used for critical errors and then calls `os.Exit(1)`
+	// FatalLevel used for critical errors and then calls `os.Exit(1)`
 	FatalLevel
+	// NoneLevel used to disable logging
+	NoneLevel
 )
 
 // String returns logger level string representation
@@ -33,6 +35,8 @@ func (l Level) String() string {
 		return "error"
 	case FatalLevel:
 		return "fatal"
+	case NoneLevel:
+		return "none"
 	}
 	return "info"
 }
@@ -58,6 +62,8 @@ func ParseLevel(lvl string) Level {
 		return ErrorLevel
 	case FatalLevel.String():
 		return FatalLevel
+	case NoneLevel.String():
+		return NoneLevel
 	}
 	return InfoLevel
 }

logger/options.go

@@ -52,6 +52,12 @@ type Options struct {
 	AddStacktrace bool
 	// DedupKeys deduplicate keys in log output
 	DedupKeys bool
+	// FatalFinalizers runs in order in [logger.Fatal] method
+	FatalFinalizers []func(context.Context)
+}
+
+var DefaultFatalFinalizer = func(ctx context.Context) {
+	os.Exit(1)
 }
 
 // NewOptions creates new options struct
@@ -65,6 +71,7 @@ func NewOptions(opts ...Option) Options {
 		AddSource:        true,
 		TimeFunc:         time.Now,
 		Meter:            meter.DefaultMeter,
+		FatalFinalizers:  []func(context.Context){DefaultFatalFinalizer},
 	}
 
 	WithMicroKeys()(&options)
@@ -76,6 +83,13 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// WithFatalFinalizers set logger.Fatal finalizers
+func WithFatalFinalizers(fncs ...func(context.Context)) Option {
+	return func(o *Options) {
+		o.FatalFinalizers = fncs
+	}
+}
+
 // WithContextAttrFuncs appends default funcs for the context attrs filler
 func WithContextAttrFuncs(fncs ...ContextAttrFunc) Option {
 	return func(o *Options) {

logger/slog/slog.go

@@ -4,14 +4,12 @@ import (
 	"context"
 	"io"
 	"log/slog"
-	"os"
 	"reflect"
 	"regexp"
 	"runtime"
 	"strconv"
 	"sync"
 	"sync/atomic"
-	"time"
 
 	"go.unistack.org/micro/v4/logger"
 	"go.unistack.org/micro/v4/semconv"
@@ -34,6 +32,7 @@ var (
 	warnValue  = slog.StringValue("warn")
 	errorValue = slog.StringValue("error")
 	fatalValue = slog.StringValue("fatal")
+	noneValue  = slog.StringValue("none")
 )
 
 type wrapper struct {
@@ -85,6 +84,8 @@ func (s *slogLogger) renameAttr(_ []string, a slog.Attr) slog.Attr {
 			a.Value = errorValue
 		case lvl >= logger.FatalLevel:
 			a.Value = fatalValue
+		case lvl >= logger.NoneLevel:
+			a.Value = noneValue
 		default:
 			a.Value = infoValue
 		}
@@ -228,11 +229,12 @@ func (s *slogLogger) Error(ctx context.Context, msg string, attrs ...interface{}
 
 func (s *slogLogger) Fatal(ctx context.Context, msg string, attrs ...interface{}) {
 	s.printLog(ctx, logger.FatalLevel, msg, attrs...)
+	for _, fn := range s.opts.FatalFinalizers {
+		fn(ctx)
+	}
 	if closer, ok := s.opts.Out.(io.Closer); ok {
 		closer.Close()
 	}
-	time.Sleep(1 * time.Second)
-	os.Exit(1)
 }
 
 func (s *slogLogger) Warn(ctx context.Context, msg string, attrs ...interface{}) {
@@ -316,6 +318,8 @@ func loggerToSlogLevel(level logger.Level) slog.Level {
 		return slog.LevelDebug - 1
 	case logger.FatalLevel:
 		return slog.LevelError + 1
+	case logger.NoneLevel:
+		return slog.LevelError + 2
 	default:
 		return slog.LevelInfo
 	}
@@ -333,6 +337,8 @@ func slogToLoggerLevel(level slog.Level) logger.Level {
 		return logger.TraceLevel
 	case slog.LevelError + 1:
 		return logger.FatalLevel
+	case slog.LevelError + 2:
+		return logger.NoneLevel
 	default:
 		return logger.InfoLevel
 	}

logger/slog/slog_test.go

@@ -36,6 +36,24 @@ func TestStacktrace(t *testing.T) {
 	}
 }
 
+func TestNoneLevel(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.NoneLevel), logger.WithOutput(buf),
+		WithHandlerFunc(slog.NewTextHandler),
+		logger.WithAddStacktrace(true),
+	)
+	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Error(ctx, "msg1", errors.New("err"))
+
+	if buf.Len() != 0 {
+		t.Fatalf("logger none level not works, buf contains: %s", buf.Bytes())
+	}
+}
+
 func TestDelayedBuffer(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)
@@ -62,7 +80,7 @@ func TestTime(t *testing.T) {
 		WithHandlerFunc(slog.NewTextHandler),
 		logger.WithAddStacktrace(true),
 		logger.WithTimeFunc(func() time.Time {
-			return time.Unix(0, 0)
+			return time.Unix(0, 0).UTC()
 		}),
 	)
 	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
@@ -71,8 +89,7 @@ func TestTime(t *testing.T) {
 
 	l.Error(ctx, "msg1", errors.New("err"))
 
-	if !bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T03:00:00.000000000+03:00`)) &&
+	if !bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T00:00:00.000000000Z`)) {
-		!bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T00:00:00.000000000Z`)) {
 		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
 	}
 }
@@ -452,3 +469,25 @@ func Test_WithContextAttrFunc(t *testing.T) {
 
 	// t.Logf("xxx %s", buf.Bytes())
 }
+
+func TestFatalFinalizers(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(
+		logger.WithLevel(logger.TraceLevel),
+		logger.WithOutput(buf),
+	)
+	if err := l.Init(
+		logger.WithFatalFinalizers(func(ctx context.Context) {
+			l.Info(ctx, "fatal finalizer")
+		})); err != nil {
+		t.Fatal(err)
+	}
+	l.Fatal(ctx, "info_msg1")
+	if !bytes.Contains(buf.Bytes(), []byte("fatal finalizer")) {
+		t.Fatalf("logger dont have fatal message, buf %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte("info_msg1")) {
+		t.Fatalf("logger dont have info_msg1 message, buf %s", buf.Bytes())
+	}
+}

metadata/context.go

@@ -0,0 +1,294 @@
+package metadata
+
+import (
+	"context"
+	"fmt"
+	"strings"
+)
+
+// In the metadata package, context and metadata are treated as immutable.
+// Deep copies of metadata are made to keep things safe and correct.
+// If a user takes a map and changes it across threads, it's their responsibility.
+//
+// 1. Incoming Context
+//
+// This context is provided by an external system and populated by the server or broker of the micro framework.
+// It should not be modified. The idea is to extract all necessary data from it,
+// validate the data, and transfer it into the current context.
+// After that, only the current context should be used throughout the code.
+//
+// 2. Current Context
+//
+// This is the context used during the execution flow.
+// You can add any needed metadata to it and pass it through your code.
+//
+// 3. Outgoing Context
+//
+// This context is for sending data to external systems.
+// You can add what you need before sending it out.
+// But it’s usually better to build and prepare this context right before making the external call,
+// instead of changing it in many places.
+//
+// Execution Flow:
+//
+// [External System]
+//       ↓
+// [Incoming Context]
+//       ↓
+// [Extract & Validate Metadata from Incoming Context]
+//       ↓
+// [Prepare Current Context]
+//       ↓
+// [Enrich Current Context]
+//       ↓
+// [Business Logic]
+//       ↓
+// [Prepare Outgoing Context]
+//       ↓
+// [External System Call]
+
+type (
+	metadataCurrentKey  struct{}
+	metadataIncomingKey struct{}
+	metadataOutgoingKey struct{}
+
+	rawMetadata struct {
+		md    Metadata
+		added [][]string
+	}
+)
+
+// NewContext creates a new context with the provided Metadata attached.
+// The Metadata must not be modified after calling this function.
+func NewContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md})
+}
+
+// NewIncomingContext creates a new context with the provided incoming Metadata attached.
+// The Metadata must not be modified after calling this function.
+func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataIncomingKey{}, rawMetadata{md: md})
+}
+
+// NewOutgoingContext creates a new context with the provided outgoing Metadata attached.
+// The Metadata must not be modified after calling this function.
+func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md})
+}
+
+// AppendContext returns a new context with the provided key-value pairs (kv)
+// merged with any existing metadata in the context. For a description of kv,
+// please refer to the Pairs documentation.
+func AppendContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// AppendOutgoingContext returns a new context with the provided key-value pairs (kv)
+// merged with any existing metadata in the context. For a description of kv,
+// please refer to the Pairs documentation.
+func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendOutgoingContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// FromContext retrieves a deep copy of the metadata from the context and returns it
+// with a boolean indicating if it was found.
+func FromContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
+}
+
+// MustContext retrieves a deep copy of the metadata from the context and panics
+// if the metadata is not found.
+func MustContext(ctx context.Context) Metadata {
+	md, ok := FromContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// FromIncomingContext retrieves a deep copy of the metadata from the context and returns it
+// with a boolean indicating if it was found.
+func FromIncomingContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromIncomingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
+}
+
+// MustIncomingContext retrieves a deep copy of the metadata from the context and panics
+// if the metadata is not found.
+func MustIncomingContext(ctx context.Context) Metadata {
+	md, ok := FromIncomingContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// FromOutgoingContext retrieves a deep copy of the metadata from the context and returns it
+// with a boolean indicating if it was found.
+func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, ok
+}
+
+// MustOutgoingContext retrieves a deep copy of the metadata from the context and panics
+// if the metadata is not found.
+func MustOutgoingContext(ctx context.Context) Metadata {
+	md, ok := FromOutgoingContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// ValueFromCurrentContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromCurrentContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// ValueFromIncomingContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromIncomingContext(ctx context.Context, key string) []string {
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := raw.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range raw.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// ValueFromOutgoingContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromOutgoingContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}

metadata/headers.go

@@ -2,18 +2,18 @@
 package metadata
 
 var (
-	// HeaderTopic is the header name that contains topic name
+	// HeaderTopic is the header name that contains topic name.
 	HeaderTopic = "Micro-Topic"
-	// HeaderContentType specifies content type of message
+	// HeaderContentType specifies content type of message.
 	HeaderContentType = "Content-Type"
-	// HeaderEndpoint specifies endpoint in service
+	// HeaderEndpoint specifies endpoint in service.
 	HeaderEndpoint = "Micro-Endpoint"
-	// HeaderService specifies service
+	// HeaderService specifies service.
 	HeaderService = "Micro-Service"
-	// HeaderTimeout specifies timeout of operation
+	// HeaderTimeout specifies timeout of operation.
 	HeaderTimeout = "Micro-Timeout"
-	// HeaderAuthorization specifies Authorization header
+	// HeaderAuthorization specifies Authorization header.
 	HeaderAuthorization = "Authorization"
-	// HeaderXRequestID specifies request id
+	// HeaderXRequestID specifies request id.
 	HeaderXRequestID = "X-Request-Id"
 )

metadata/helpers.go

@@ -0,0 +1,7 @@
+package metadata
+
+func copyOf(v []string) []string {
+	vals := make([]string, len(v))
+	copy(vals, v)
+	return vals
+}

metadata/iterator.go

@@ -0,0 +1,37 @@
+package metadata
+
+import "sort"
+
+type Iterator struct {
+	md   Metadata
+	keys []string
+	cur  int
+	cnt  int
+}
+
+// Next advances the iterator to the next element.
+func (iter *Iterator) Next(k *string, v *[]string) bool {
+	if iter.cur+1 > iter.cnt {
+		return false
+	}
+
+	if k != nil && v != nil {
+		*k = iter.keys[iter.cur]
+		vv := iter.md[*k]
+		*v = make([]string, len(vv))
+		copy(*v, vv)
+		iter.cur++
+	}
+	return true
+}
+
+// Iterator returns an iterator for iterating over metadata in sorted order.
+func (md Metadata) Iterator() *Iterator {
+	iter := &Iterator{md: md, cnt: len(md)}
+	iter.keys = make([]string, 0, iter.cnt)
+	for k := range md {
+		iter.keys = append(iter.keys, k)
+	}
+	sort.Strings(iter.keys)
+	return iter
+}

metadata/metadata.go

@@ -1,21 +1,18 @@
 package metadata
 
 import (
-	"context"
 	"fmt"
 	"net/textproto"
-	"sort"
 	"strings"
 )
 
-// defaultMetadataSize used when need to init new Metadata
+// defaultMetadataSize is used when initializing new Metadata.
 var defaultMetadataSize = 2
 
-// Metadata is a mapping from metadata keys to values. Users should use the following
+// Metadata maps keys to values. Use the New, NewWithMetadata and Pairs functions to create it.
-// two convenience functions New and Pairs to generate Metadata.
 type Metadata map[string][]string
 
-// New creates an zero Metadata.
+// New creates a zero-value Metadata with the specified size.
 func New(l int) Metadata {
 	if l == 0 {
 		l = defaultMetadataSize
@@ -24,7 +21,7 @@ func New(l int) Metadata {
 	return md
 }
 
-// NewWithMetadata creates an Metadata from a given key-value map.
+// NewWithMetadata creates a Metadata from the provided key-value map.
 func NewWithMetadata(m map[string]string) Metadata {
 	md := make(Metadata, len(m))
 	for key, val := range m {
@@ -33,8 +30,7 @@ func NewWithMetadata(m map[string]string) Metadata {
 	return md
 }
 
-// Pairs returns an Metadata formed by the mapping of key, value ...
+// Pairs returns a Metadata formed from the key-value mapping. It panics if the length of kv is odd.
-// Pairs panics if len(kv) is odd.
 func Pairs(kv ...string) Metadata {
 	if len(kv)%2 == 1 {
 		panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv)))
@@ -46,12 +42,19 @@ func Pairs(kv ...string) Metadata {
 	return md
 }
 
-// Len returns the number of items in Metadata.
+// Join combines multiple Metadatas into a single Metadata.
-func (md Metadata) Len() int {
+// The order of values for each key is determined by the order in which the Metadatas are provided to Join.
-	return len(md)
+func Join(mds ...Metadata) Metadata {
+	out := Metadata{}
+	for _, md := range mds {
+		for k, v := range md {
+			out[k] = append(out[k], v...)
+		}
+	}
+	return out
 }
 
-// Copy returns a copy of Metadata.
+// Copy returns a deep copy of Metadata.
 func Copy(src Metadata) Metadata {
 	out := make(Metadata, len(src))
 	for k, v := range src {
@@ -60,7 +63,7 @@ func Copy(src Metadata) Metadata {
 	return out
 }
 
-// Copy returns a copy of Metadata.
+// Copy returns a deep copy of Metadata.
 func (md Metadata) Copy() Metadata {
 	out := make(Metadata, len(md))
 	for k, v := range md {
@@ -69,7 +72,19 @@ func (md Metadata) Copy() Metadata {
 	return out
 }
 
-// AsMap returns a copy of Metadata with map[string]string.
+// CopyTo performs a deep copy of Metadata to the out.
+func (md Metadata) CopyTo(out Metadata) {
+	for k, v := range md {
+		out[k] = copyOf(v)
+	}
+}
+
+// Len returns the number of items in Metadata.
+func (md Metadata) Len() int {
+	return len(md)
+}
+
+// AsMap returns a deep copy of Metadata as a map[string]string
 func (md Metadata) AsMap() map[string]string {
 	out := make(map[string]string, len(md))
 	for k, v := range md {
@@ -78,8 +93,7 @@ func (md Metadata) AsMap() map[string]string {
 	return out
 }
 
-// AsHTTP1 returns a copy of Metadata
+// AsHTTP1 returns a deep copy of Metadata with keys converted to canonical MIME header key format.
-// with CanonicalMIMEHeaderKey.
 func (md Metadata) AsHTTP1() map[string][]string {
 	out := make(map[string][]string, len(md))
 	for k, v := range md {
@@ -88,8 +102,7 @@ func (md Metadata) AsHTTP1() map[string][]string {
 	return out
 }
 
-// AsHTTP1 returns a copy of Metadata
+// AsHTTP2 returns a deep copy of Metadata with keys converted to lowercase.
-// with strings.ToLower.
 func (md Metadata) AsHTTP2() map[string][]string {
 	out := make(map[string][]string, len(md))
 	for k, v := range md {
@@ -98,14 +111,10 @@ func (md Metadata) AsHTTP2() map[string][]string {
 	return out
 }
 
-// CopyTo copies Metadata to out.
+// Get retrieves the values for a given key, checking the key in three formats:
-func (md Metadata) CopyTo(out Metadata) {
+// - exact case,
-	for k, v := range md {
+// - lower case,
-		out[k] = copyOf(v)
+// - canonical MIME header key format.
-	}
-}
-
-// Get obtains the values for a given key.
 func (md Metadata) Get(k string) []string {
 	v, ok := md[k]
 	if !ok {
@@ -117,13 +126,12 @@ func (md Metadata) Get(k string) []string {
 	return v
 }
 
-// GetJoined obtains the values for a given key
+// GetJoined retrieves the values for a given key and joins them into a single string, separated by commas.
-// with joined values with "," symbol
 func (md Metadata) GetJoined(k string) string {
 	return strings.Join(md.Get(k), ",")
 }
 
-// Set sets the value of a given key with a slice of values.
+// Set assigns the values to the given key.
 func (md Metadata) Set(key string, vals ...string) {
 	if len(vals) == 0 {
 		return
@@ -131,8 +139,7 @@ func (md Metadata) Set(key string, vals ...string) {
 	md[key] = vals
 }
 
-// Append adds the values to key k, not overwriting what was already stored at
+// Append adds values to the existing values for the given key.
-// that key.
 func (md Metadata) Append(key string, vals ...string) {
 	if len(vals) == 0 {
 		return
@@ -140,7 +147,10 @@ func (md Metadata) Append(key string, vals ...string) {
 	md[key] = append(md[key], vals...)
 }
 
-// Del removes the values for a given keys k.
+// Del removes the values for the given keys k. It checks and removes the keys in the following formats:
+// - exact case,
+// - lower case,
+// - canonical MIME header key format.
 func (md Metadata) Del(k ...string) {
 	for i := range k {
 		delete(md, k[i])
@@ -148,303 +158,3 @@ func (md Metadata) Del(k ...string) {
 		delete(md, textproto.CanonicalMIMEHeaderKey(k[i]))
 	}
 }
-
-// Join joins any number of Metadatas into a single Metadata.
-//
-// The order of values for each key is determined by the order in which the Metadatas
-// containing those values are presented to Join.
-func Join(mds ...Metadata) Metadata {
-	out := Metadata{}
-	for _, Metadata := range mds {
-		for k, v := range Metadata {
-			out[k] = append(out[k], v...)
-		}
-	}
-	return out
-}
-
-type (
-	metadataIncomingKey struct{}
-	metadataOutgoingKey struct{}
-	metadataCurrentKey  struct{}
-)
-
-// NewContext creates a new context with Metadata attached. Metadata must
-// not be modified after calling this function.
-func NewContext(ctx context.Context, md Metadata) context.Context {
-	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md})
-}
-
-// NewIncomingContext creates a new context with incoming Metadata attached. Metadata must
-// not be modified after calling this function.
-func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
-	return context.WithValue(ctx, metadataIncomingKey{}, rawMetadata{md: md})
-}
-
-// NewOutgoingContext creates a new context with outgoing Metadata attached. If used
-// in conjunction with AppendOutgoingContext, NewOutgoingContext will
-// overwrite any previously-appended metadata. Metadata must not be modified after
-// calling this function.
-func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
-	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md})
-}
-
-// AppendContext returns a new context with the provided kv merged
-// with any existing metadata in the context. Please refer to the documentation
-// of Pairs for a description of kv.
-func AppendContext(ctx context.Context, kv ...string) context.Context {
-	if len(kv)%2 == 1 {
-		panic(fmt.Sprintf("metadata: AppendContext got an odd number of input pairs for metadata: %d", len(kv)))
-	}
-	md, _ := ctx.Value(metadataCurrentKey{}).(rawMetadata)
-	added := make([][]string, len(md.added)+1)
-	copy(added, md.added)
-	kvCopy := make([]string, 0, len(kv))
-	for i := 0; i < len(kv); i += 2 {
-		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
-	}
-	added[len(added)-1] = kvCopy
-	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md.md, added: added})
-}
-
-// AppendOutgoingContext returns a new context with the provided kv merged
-// with any existing metadata in the context. Please refer to the documentation
-// of Pairs for a description of kv.
-func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
-	if len(kv)%2 == 1 {
-		panic(fmt.Sprintf("metadata: AppendOutgoingContext got an odd number of input pairs for metadata: %d", len(kv)))
-	}
-	md, _ := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
-	added := make([][]string, len(md.added)+1)
-	copy(added, md.added)
-	kvCopy := make([]string, 0, len(kv))
-	for i := 0; i < len(kv); i += 2 {
-		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
-	}
-	added[len(added)-1] = kvCopy
-	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md.md, added: added})
-}
-
-// FromContext returns the metadata in ctx if it exists.
-func FromContext(ctx context.Context) (Metadata, bool) {
-	raw, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
-	if !ok {
-		return nil, false
-	}
-	metadataSize := len(raw.md)
-	for i := range raw.added {
-		metadataSize += len(raw.added[i]) / 2
-	}
-
-	out := make(Metadata, metadataSize)
-	for k, v := range raw.md {
-		out[k] = copyOf(v)
-	}
-	for _, added := range raw.added {
-		if len(added)%2 == 1 {
-			panic(fmt.Sprintf("metadata: FromContext got an odd number of input pairs for metadata: %d", len(added)))
-		}
-
-		for i := 0; i < len(added); i += 2 {
-			out[added[i]] = append(out[added[i]], added[i+1])
-		}
-	}
-	return out, true
-}
-
-// MustContext returns the metadata in ctx.
-func MustContext(ctx context.Context) Metadata {
-	md, ok := FromContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// FromIncomingContext returns the incoming metadata in ctx if it exists.
-func FromIncomingContext(ctx context.Context) (Metadata, bool) {
-	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
-	if !ok {
-		return nil, false
-	}
-	metadataSize := len(raw.md)
-	for i := range raw.added {
-		metadataSize += len(raw.added[i]) / 2
-	}
-
-	out := make(Metadata, metadataSize)
-	for k, v := range raw.md {
-		out[k] = copyOf(v)
-	}
-	for _, added := range raw.added {
-		if len(added)%2 == 1 {
-			panic(fmt.Sprintf("metadata: FromIncomingContext got an odd number of input pairs for metadata: %d", len(added)))
-		}
-
-		for i := 0; i < len(added); i += 2 {
-			out[added[i]] = append(out[added[i]], added[i+1])
-		}
-	}
-	return out, true
-}
-
-// MustIncomingContext returns the incoming metadata in ctx.
-func MustIncomingContext(ctx context.Context) Metadata {
-	md, ok := FromIncomingContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// ValueFromIncomingContext returns the metadata value corresponding to the metadata
-// key from the incoming metadata if it exists. Keys are matched in a case insensitive
-// manner.
-func ValueFromIncomingContext(ctx context.Context, key string) []string {
-	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
-	if !ok {
-		return nil
-	}
-
-	if v, ok := raw.md[key]; ok {
-		return copyOf(v)
-	}
-	for k, v := range raw.md {
-		// Case insensitive comparison: Metadata is a map, and there's no guarantee
-		// that the Metadata attached to the context is created using our helper
-		// functions.
-		if strings.EqualFold(k, key) {
-			return copyOf(v)
-		}
-	}
-	return nil
-}
-
-// ValueFromCurrentContext returns the metadata value corresponding to the metadata
-// key from the incoming metadata if it exists. Keys are matched in a case insensitive
-// manner.
-func ValueFromCurrentContext(ctx context.Context, key string) []string {
-	md, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
-	if !ok {
-		return nil
-	}
-
-	if v, ok := md.md[key]; ok {
-		return copyOf(v)
-	}
-	for k, v := range md.md {
-		// Case insensitive comparison: Metadata is a map, and there's no guarantee
-		// that the Metadata attached to the context is created using our helper
-		// functions.
-		if strings.EqualFold(k, key) {
-			return copyOf(v)
-		}
-	}
-	return nil
-}
-
-// MustOutgoingContext returns the outgoing metadata in ctx.
-func MustOutgoingContext(ctx context.Context) Metadata {
-	md, ok := FromOutgoingContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// ValueFromOutgoingContext returns the metadata value corresponding to the metadata
-// key from the incoming metadata if it exists. Keys are matched in a case insensitive
-// manner.
-func ValueFromOutgoingContext(ctx context.Context, key string) []string {
-	md, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
-	if !ok {
-		return nil
-	}
-
-	if v, ok := md.md[key]; ok {
-		return copyOf(v)
-	}
-	for k, v := range md.md {
-		// Case insensitive comparison: Metadata is a map, and there's no guarantee
-		// that the Metadata attached to the context is created using our helper
-		// functions.
-		if strings.EqualFold(k, key) {
-			return copyOf(v)
-		}
-	}
-	return nil
-}
-
-func copyOf(v []string) []string {
-	vals := make([]string, len(v))
-	copy(vals, v)
-	return vals
-}
-
-// FromOutgoingContext returns the outgoing metadata in ctx if it exists.
-func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
-	raw, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
-	if !ok {
-		return nil, false
-	}
-
-	metadataSize := len(raw.md)
-	for i := range raw.added {
-		metadataSize += len(raw.added[i]) / 2
-	}
-
-	out := make(Metadata, metadataSize)
-	for k, v := range raw.md {
-		out[k] = copyOf(v)
-	}
-	for _, added := range raw.added {
-		if len(added)%2 == 1 {
-			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
-		}
-
-		for i := 0; i < len(added); i += 2 {
-			out[added[i]] = append(out[added[i]], added[i+1])
-		}
-	}
-	return out, ok
-}
-
-type rawMetadata struct {
-	md    Metadata
-	added [][]string
-}
-
-// Iterator used to iterate over metadata with order
-type Iterator struct {
-	md   Metadata
-	keys []string
-	cur  int
-	cnt  int
-}
-
-// Next advance iterator to next element
-func (iter *Iterator) Next(k *string, v *[]string) bool {
-	if iter.cur+1 > iter.cnt {
-		return false
-	}
-
-	if k != nil && v != nil {
-		*k = iter.keys[iter.cur]
-		vv := iter.md[*k]
-		*v = make([]string, len(vv))
-		copy(*v, vv)
-		iter.cur++
-	}
-	return true
-}
-
-// Iterator returns the itarator for metadata in sorted order
-func (md Metadata) Iterator() *Iterator {
-	iter := &Iterator{md: md, cnt: len(md)}
-	iter.keys = make([]string, 0, iter.cnt)
-	for k := range md {
-		iter.keys = append(iter.keys, k)
-	}
-	sort.Strings(iter.keys)
-	return iter
-}

meter/meter.go

@@ -4,8 +4,8 @@ package meter
 import (
 	"io"
 	"sort"
-	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -59,6 +59,8 @@ type Meter interface {
 	Options() Options
 	// String return meter type
 	String() string
+	// Unregister metric name and drop all data
+	Unregister(name string, labels ...string) bool
 }
 
 // Counter is a counter
@@ -80,7 +82,11 @@ type FloatCounter interface {
 
 // Gauge is a float64 gauge
 type Gauge interface {
+	Add(float64)
 	Get() float64
+	Set(float64)
+	Dec()
+	Inc()
 }
 
 // Histogram is a histogram for non-negative values with automatically created buckets
@@ -117,6 +123,39 @@ func BuildLabels(labels ...string) []string {
 	return labels
 }
 
+var spool = newStringsPool(500)
+
+type stringsPool struct {
+	p *sync.Pool
+	c int
+}
+
+func newStringsPool(size int) *stringsPool {
+	p := &stringsPool{c: size}
+	p.p = &sync.Pool{
+		New: func() interface{} {
+			return &strings.Builder{}
+		},
+	}
+	return p
+}
+
+func (p *stringsPool) Cap() int {
+	return p.c
+}
+
+func (p *stringsPool) Get() *strings.Builder {
+	return p.p.Get().(*strings.Builder)
+}
+
+func (p *stringsPool) Put(b *strings.Builder) {
+	if b.Cap() > p.c {
+		return
+	}
+	b.Reset()
+	p.p.Put(b)
+}
+
 // BuildName used to combine metric with labels.
 // If labels count is odd, drop last element
 func BuildName(name string, labels ...string) string {
@@ -125,8 +164,6 @@ func BuildName(name string, labels ...string) string {
 	}
 
 	if len(labels) > 2 {
-		sort.Sort(byKey(labels))
-
 		idx := 0
 		for {
 			if labels[idx] == labels[idx+2] {
@@ -141,7 +178,9 @@ func BuildName(name string, labels ...string) string {
 		}
 	}
 
-	var b strings.Builder
+	b := spool.Get()
+	defer spool.Put(b)
+
 	_, _ = b.WriteString(name)
 	_, _ = b.WriteRune('{')
 	for idx := 0; idx < len(labels); idx += 2 {
@@ -149,8 +188,9 @@ func BuildName(name string, labels ...string) string {
 			_, _ = b.WriteRune(',')
 		}
 		_, _ = b.WriteString(labels[idx])
-		_, _ = b.WriteString(`=`)
+		_, _ = b.WriteString(`="`)
-		_, _ = b.WriteString(strconv.Quote(labels[idx+1]))
+		_, _ = b.WriteString(labels[idx+1])
+		_, _ = b.WriteRune('"')
 	}
 	_, _ = b.WriteRune('}')
 

meter/meter_test.go

@@ -50,11 +50,12 @@ func TestBuildName(t *testing.T) {
 	data := map[string][]string{
 		`my_metric{firstlabel="value2",zerolabel="value3"}`: {
 			"my_metric",
-			"zerolabel", "value3", "firstlabel", "value2",
+			"firstlabel", "value2",
+			"zerolabel", "value3",
 		},
 		`my_metric{broker="broker2",register="mdns",server="tcp"}`: {
 			"my_metric",
-			"broker", "broker1", "broker", "broker2", "server", "http", "server", "tcp", "register", "mdns",
+			"broker", "broker1", "broker", "broker2", "register", "mdns", "server", "http", "server", "tcp",
 		},
 		`my_metric{aaa="aaa"}`: {
 			"my_metric",

meter/noop.go

@@ -28,6 +28,10 @@ func (r *noopMeter) Name() string {
 	return r.opts.Name
 }
 
+func (r *noopMeter) Unregister(name string, labels ...string) bool {
+	return true
+}
+
 // Init initialize options
 func (r *noopMeter) Init(opts ...Option) error {
 	for _, o := range opts {
@@ -132,6 +136,18 @@ type noopGauge struct {
 	labels []string
 }
 
+func (r *noopGauge) Add(float64) {
+}
+
+func (r *noopGauge) Set(float64) {
+}
+
+func (r *noopGauge) Inc() {
+}
+
+func (r *noopGauge) Dec() {
+}
+
 func (r *noopGauge) Get() float64 {
 	return 0
 }

micro_test.go

@@ -91,7 +91,7 @@ func (p *bro) Connect(_ context.Context) error { return nil }
 func (p *bro) Disconnect(_ context.Context) error { return nil }
 
 // NewMessage creates new message
-func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.PublishOption) (broker.Message, error) {
+func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.MessageOption) (broker.Message, error) {
 	return nil, nil
 }
 

profiler/http/http.go

@@ -12,7 +12,7 @@ import (
 
 type httpProfile struct {
 	server  *http.Server
-	sync.Mutex
+	mu      sync.Mutex
 	running bool
 }
 
@@ -21,8 +21,8 @@ var DefaultAddress = ":6060"
 
 // Start the profiler
 func (h *httpProfile) Start() error {
-	h.Lock()
+	h.mu.Lock()
-	defer h.Unlock()
+	defer h.mu.Unlock()
 
 	if h.running {
 		return nil
@@ -30,9 +30,9 @@ func (h *httpProfile) Start() error {
 
 	go func() {
 		if err := h.server.ListenAndServe(); err != nil {
-			h.Lock()
+			h.mu.Lock()
 			h.running = false
-			h.Unlock()
+			h.mu.Unlock()
 		}
 	}()
 
@@ -43,8 +43,8 @@ func (h *httpProfile) Start() error {
 
 // Stop the profiler
 func (h *httpProfile) Stop() error {
-	h.Lock()
+	h.mu.Lock()
-	defer h.Unlock()
+	defer h.mu.Unlock()
 
 	if !h.running {
 		return nil

profiler/pprof/pprof.go

@@ -17,7 +17,7 @@ type profiler struct {
 	cpuFile *os.File
 	memFile *os.File
 	opts    profile.Options
-	sync.Mutex
+	mu      sync.Mutex
 	running bool
 }
 
@@ -39,8 +39,8 @@ func (p *profiler) writeHeap(f *os.File) {
 }
 
 func (p *profiler) Start() error {
-	p.Lock()
+	p.mu.Lock()
-	defer p.Unlock()
+	defer p.mu.Unlock()
 
 	if p.running {
 		return nil
@@ -86,8 +86,8 @@ func (p *profiler) Start() error {
 }
 
 func (p *profiler) Stop() error {
-	p.Lock()
+	p.mu.Lock()
-	defer p.Unlock()
+	defer p.mu.Unlock()
 
 	select {
 	case <-p.exit:

register/memory/memory.go

@@ -33,7 +33,7 @@ type memory struct {
 	records  map[string]services
 	watchers map[string]*watcher
 	opts     register.Options
-	sync.RWMutex
+	mu       sync.RWMutex
 }
 
 // services is a KV map with service name as the key and a map of records as the value
@@ -57,7 +57,7 @@ func (m *memory) ttlPrune() {
 	defer prune.Stop()
 
 	for range prune.C {
-		m.Lock()
+		m.mu.Lock()
 		for namespace, services := range m.records {
 			for service, versions := range services {
 				for version, record := range versions {
@@ -72,24 +72,24 @@ func (m *memory) ttlPrune() {
 				}
 			}
 		}
-		m.Unlock()
+		m.mu.Unlock()
 	}
 }
 
 func (m *memory) sendEvent(r *register.Result) {
-	m.RLock()
+	m.mu.RLock()
 	watchers := make([]*watcher, 0, len(m.watchers))
 	for _, w := range m.watchers {
 		watchers = append(watchers, w)
 	}
-	m.RUnlock()
+	m.mu.RUnlock()
 
 	for _, w := range watchers {
 		select {
 		case <-w.exit:
-			m.Lock()
+			m.mu.Lock()
 			delete(m.watchers, w.id)
-			m.Unlock()
+			m.mu.Unlock()
 		default:
 			select {
 			case w.res <- r:
@@ -113,8 +113,8 @@ func (m *memory) Init(opts ...register.Option) error {
 	}
 
 	// add services
-	m.Lock()
+	m.mu.Lock()
-	defer m.Unlock()
+	defer m.mu.Unlock()
 
 	return nil
 }
@@ -124,8 +124,8 @@ func (m *memory) Options() register.Options {
 }
 
 func (m *memory) Register(_ context.Context, s *register.Service, opts ...register.RegisterOption) error {
-	m.Lock()
+	m.mu.Lock()
-	defer m.Unlock()
+	defer m.mu.Unlock()
 
 	options := register.NewRegisterOptions(opts...)
 
@@ -197,8 +197,8 @@ func (m *memory) Register(_ context.Context, s *register.Service, opts ...regist
 }
 
 func (m *memory) Deregister(ctx context.Context, s *register.Service, opts ...register.DeregisterOption) error {
-	m.Lock()
+	m.mu.Lock()
-	defer m.Unlock()
+	defer m.mu.Unlock()
 
 	options := register.NewDeregisterOptions(opts...)
 
@@ -264,9 +264,9 @@ func (m *memory) LookupService(ctx context.Context, name string, opts ...registe
 
 	// if it's a wildcard domain, return from all domains
 	if options.Namespace == register.WildcardNamespace {
-		m.RLock()
+		m.mu.RLock()
 		recs := m.records
-		m.RUnlock()
+		m.mu.RUnlock()
 
 		var services []*register.Service
 
@@ -286,8 +286,8 @@ func (m *memory) LookupService(ctx context.Context, name string, opts ...registe
 		return services, nil
 	}
 
-	m.RLock()
+	m.mu.RLock()
-	defer m.RUnlock()
+	defer m.mu.RUnlock()
 
 	// check the domain exists
 	services, ok := m.records[options.Namespace]
@@ -319,9 +319,9 @@ func (m *memory) ListServices(ctx context.Context, opts ...register.ListOption)
 
 	// if it's a wildcard domain, list from all domains
 	if options.Namespace == register.WildcardNamespace {
-		m.RLock()
+		m.mu.RLock()
 		recs := m.records
-		m.RUnlock()
+		m.mu.RUnlock()
 
 		var services []*register.Service
 
@@ -336,8 +336,8 @@ func (m *memory) ListServices(ctx context.Context, opts ...register.ListOption)
 		return services, nil
 	}
 
-	m.RLock()
+	m.mu.RLock()
-	defer m.RUnlock()
+	defer m.mu.RUnlock()
 
 	// ensure the domain exists
 	services, ok := m.records[options.Namespace]
@@ -371,9 +371,9 @@ func (m *memory) Watch(ctx context.Context, opts ...register.WatchOption) (regis
 		wo:   wo,
 	}
 
-	m.Lock()
+	m.mu.Lock()
 	m.watchers[w.id] = w
-	m.Unlock()
+	m.mu.Unlock()
 
 	return w, nil
 }

register/register.go

@@ -69,6 +69,7 @@ type Service struct {
 type Node struct {
 	Metadata metadata.Metadata `json:"metadata,omitempty"`
 	ID       string            `json:"id,omitempty"`
+	// Address also prefixed with scheme like grpc://xx.xx.xx.xx:1234
 	Address string `json:"address,omitempty"`
 }
 

server/noop.go

@@ -57,7 +57,7 @@ type noopServer struct {
 	handlers   map[string]Handler
 	exit       chan chan error
 	opts       Options
-	sync.RWMutex
+	mu         sync.RWMutex
 	registered bool
 	started    bool
 }
@@ -125,10 +125,10 @@ func (n *noopServer) String() string {
 
 //nolint:gocyclo
 func (n *noopServer) Register() error {
-	n.RLock()
+	n.mu.RLock()
 	rsvc := n.rsvc
 	config := n.opts
-	n.RUnlock()
+	n.mu.RUnlock()
 
 	// if service already filled, reuse it and return early
 	if rsvc != nil {
@@ -144,9 +144,9 @@ func (n *noopServer) Register() error {
 		return err
 	}
 
-	n.RLock()
+	n.mu.RLock()
 	registered := n.registered
-	n.RUnlock()
+	n.mu.RUnlock()
 
 	if !registered {
 		if config.Logger.V(logger.InfoLevel) {
@@ -164,8 +164,8 @@ func (n *noopServer) Register() error {
 		return nil
 	}
 
-	n.Lock()
+	n.mu.Lock()
-	defer n.Unlock()
+	defer n.mu.Unlock()
 
 	n.registered = true
 	if cacheService {
@@ -178,9 +178,9 @@ func (n *noopServer) Register() error {
 func (n *noopServer) Deregister() error {
 	var err error
 
-	n.RLock()
+	n.mu.RLock()
 	config := n.opts
-	n.RUnlock()
+	n.mu.RUnlock()
 
 	service, err := NewRegisterService(n)
 	if err != nil {
@@ -195,29 +195,29 @@ func (n *noopServer) Deregister() error {
 		return err
 	}
 
-	n.Lock()
+	n.mu.Lock()
 	n.rsvc = nil
 
 	if !n.registered {
-		n.Unlock()
+		n.mu.Unlock()
 		return nil
 	}
 
 	n.registered = false
 
-	n.Unlock()
+	n.mu.Unlock()
 	return nil
 }
 
 //nolint:gocyclo
 func (n *noopServer) Start() error {
-	n.RLock()
+	n.mu.RLock()
 	if n.started {
-		n.RUnlock()
+		n.mu.RUnlock()
 		return nil
 	}
 	config := n.Options()
-	n.RUnlock()
+	n.mu.RUnlock()
 
 	// use 127.0.0.1 to avoid scan of all network interfaces
 	addr, err := maddr.Extract("127.0.0.1")
@@ -235,11 +235,11 @@ func (n *noopServer) Start() error {
 		config.Logger.Info(n.opts.Context, "server [noop] Listening on "+config.Address)
 	}
 
-	n.Lock()
+	n.mu.Lock()
 	if len(config.Advertise) == 0 {
 		config.Advertise = config.Address
 	}
-	n.Unlock()
+	n.mu.Unlock()
 
 	// use RegisterCheck func before register
 	// nolint: nestif
@@ -273,9 +273,9 @@ func (n *noopServer) Start() error {
 			select {
 			// register self on interval
 			case <-t.C:
-				n.RLock()
+				n.mu.RLock()
 				registered := n.registered
-				n.RUnlock()
+				n.mu.RUnlock()
 				rerr := config.RegisterCheck(config.Context)
 				// nolint: nestif
 				if rerr != nil && registered {
@@ -332,29 +332,29 @@ func (n *noopServer) Start() error {
 	}()
 
 	// mark the server as started
-	n.Lock()
+	n.mu.Lock()
 	n.started = true
-	n.Unlock()
+	n.mu.Unlock()
 
 	return nil
 }
 
 func (n *noopServer) Stop() error {
-	n.RLock()
+	n.mu.RLock()
 	if !n.started {
-		n.RUnlock()
+		n.mu.RUnlock()
 		return nil
 	}
-	n.RUnlock()
+	n.mu.RUnlock()
 
 	ch := make(chan error)
 	n.exit <- ch
 
 	err := <-ch
-	n.Lock()
+	n.mu.Lock()
 	n.rsvc = nil
 	n.started = false
-	n.Unlock()
+	n.mu.Unlock()
 
 	return err
 }

service.go

@@ -98,7 +98,7 @@ func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOptio
 type service struct {
 	done    chan struct{}
 	opts    Options
-	sync.RWMutex
+	mu      sync.RWMutex
 	stopped bool
 }
 
@@ -321,9 +321,9 @@ func (s *service) Health() bool {
 func (s *service) Start() error {
 	var err error
 
-	s.RLock()
+	s.mu.RLock()
 	config := s.opts
-	s.RUnlock()
+	s.mu.RUnlock()
 
 	for _, cfg := range s.opts.Configs {
 		if cfg.Options().Struct == nil {
@@ -380,9 +380,9 @@ func (s *service) Start() error {
 }
 
 func (s *service) Stop() error {
-	s.RLock()
+	s.mu.RLock()
 	config := s.opts
-	s.RUnlock()
+	s.mu.RUnlock()
 
 	if config.Loggers[0].V(logger.InfoLevel) {
 		config.Loggers[0].Info(s.opts.Context, fmt.Sprintf("stoppping [service] %s", s.Name()))
@@ -457,13 +457,13 @@ func (s *service) Run() error {
 // notifyShutdown marks the service as stopped and closes the done channel.
 // It ensures the channel is closed only once, preventing multiple closures.
 func (s *service) notifyShutdown() {
-	s.Lock()
+	s.mu.Lock()
 	if s.stopped {
-		s.Unlock()
+		s.mu.Unlock()
 		return
 	}
 	s.stopped = true
-	s.Unlock()
+	s.mu.Unlock()
 
 	close(s.done)
 }

store/noop.go

@@ -139,7 +139,7 @@ func (n *noopStore) fnExists(ctx context.Context, _ string, _ ...ExistsOption) e
 		return ctx.Err()
 	default:
 	}
-	return nil
+	return ErrNotFound
 }
 
 func (n *noopStore) Write(ctx context.Context, key string, val interface{}, opts ...WriteOption) error {

store/noop_test.go

@@ -2,6 +2,7 @@ package store
 
 import (
 	"context"
+	"errors"
 	"testing"
 )
 
@@ -25,7 +26,8 @@ func TestHook(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := s.Exists(context.TODO(), "test"); err != nil {
+	err := s.Exists(context.TODO(), "test")
+	if !errors.Is(err, ErrNotFound) {
 		t.Fatal(err)
 	}
 

sync/memory.go

@@ -9,7 +9,7 @@ type memorySync struct {
 	locks   map[string]*memoryLock
 	options Options
 
-	mtx gosync.RWMutex
+	mu gosync.RWMutex
 }
 
 type memoryLock struct {
@@ -74,7 +74,7 @@ func (m *memorySync) Options() Options {
 
 func (m *memorySync) Lock(id string, opts ...LockOption) error {
 	// lock our access
-	m.mtx.Lock()
+	m.mu.Lock()
 
 	var options LockOptions
 	for _, o := range opts {
@@ -90,11 +90,11 @@ func (m *memorySync) Lock(id string, opts ...LockOption) error {
 			release: make(chan bool),
 		}
 		// unlock
-		m.mtx.Unlock()
+		m.mu.Unlock()
 		return nil
 	}
 
-	m.mtx.Unlock()
+	m.mu.Unlock()
 
 	// set wait time
 	var wait <-chan time.Time
@@ -124,12 +124,12 @@ lockLoop:
 		// wait for the lock to be released
 		select {
 		case <-lk.release:
-			m.mtx.Lock()
+			m.mu.Lock()
 
 			// someone locked before us
 			lk, ok = m.locks[id]
 			if ok {
-				m.mtx.Unlock()
+				m.mu.Unlock()
 				continue
 			}
 
@@ -141,7 +141,7 @@ lockLoop:
 				release: make(chan bool),
 			}
 
-			m.mtx.Unlock()
+			m.mu.Unlock()
 
 			break lockLoop
 		case <-ttl:
@@ -160,8 +160,8 @@ lockLoop:
 }
 
 func (m *memorySync) Unlock(id string) error {
-	m.mtx.Lock()
+	m.mu.Lock()
-	defer m.mtx.Unlock()
+	defer m.mu.Unlock()
 
 	lk, ok := m.locks[id]
 	// no lock exists

tracer/memory/memory.go

@@ -46,6 +46,10 @@ func (s memoryStringer) String() string {
 	return s.s
 }
 
+func (t *Tracer) Enabled() bool {
+	return t.opts.Enabled
+}
+
 func (t *Tracer) Flush(_ context.Context) error {
 	return nil
 }

tracer/noop.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v4/util/id"
+	"github.com/google/uuid"
 )
 
 var _ Tracer = (*noopTracer)(nil)
@@ -18,6 +18,12 @@ func (t *noopTracer) Spans() []Span {
 	return t.spans
 }
 
+var uuidNil = uuid.Nil.String()
+
+func (t *noopTracer) Enabled() bool {
+	return t.opts.Enabled
+}
+
 func (t *noopTracer) Start(ctx context.Context, name string, opts ...SpanOption) (context.Context, Span) {
 	options := NewSpanOptions(opts...)
 	span := &noopSpan{
@@ -28,8 +34,8 @@ func (t *noopTracer) Start(ctx context.Context, name string, opts ...SpanOption)
 		labels:    options.Labels,
 		kind:      options.Kind,
 	}
-	span.spanID.s, _ = id.New()
+	span.spanID.s = uuidNil
-	span.traceID.s, _ = id.New()
+	span.traceID.s = uuidNil
 	if span.ctx == nil {
 		span.ctx = context.Background()
 	}

tracer/options.go

@@ -142,6 +142,8 @@ type Options struct {
 	Name string
 	// ContextAttrFuncs contains funcs that provides tracing
 	ContextAttrFuncs []ContextAttrFunc
+	// Enabled specify trace status
+	Enabled bool
 }
 
 // Option func signature
@@ -181,6 +183,7 @@ func NewOptions(opts ...Option) Options {
 		Logger:           logger.DefaultLogger,
 		Context:          context.Background(),
 		ContextAttrFuncs: DefaultContextAttrFuncs,
+		Enabled:          true,
 	}
 	for _, o := range opts {
 		o(&options)
@@ -194,3 +197,10 @@ func Name(n string) Option {
 		o.Name = n
 	}
 }
+
+// Disabled disable tracer
+func Disabled(b bool) Option {
+	return func(o *Options) {
+		o.Enabled = !b
+	}
+}

tracer/tracer.go

@@ -29,10 +29,10 @@ type ContextAttrFunc func(ctx context.Context) []interface{}
 func init() {
 	logger.DefaultContextAttrFuncs = append(logger.DefaultContextAttrFuncs,
 		func(ctx context.Context) []interface{} {
-			if span, ok := SpanFromContext(ctx); ok {
+			if sp, ok := SpanFromContext(ctx); ok && sp != nil && sp.IsRecording() {
 				return []interface{}{
-					TraceIDKey, span.TraceID(),
+					TraceIDKey, sp.TraceID(),
-					SpanIDKey, span.SpanID(),
+					SpanIDKey, sp.SpanID(),
 				}
 			}
 			return nil
@@ -51,6 +51,8 @@ type Tracer interface {
 	// Extract(ctx context.Context)
 	// Flush flushes spans
 	Flush(ctx context.Context) error
+	// Enabled returns tracer status
+	Enabled() bool
 }
 
 type Span interface {

util/buffer/seeker_buffer.go

@@ -1,13 +1,16 @@
 package buffer
 
-import "io"
+import (
+	"fmt"
+	"io"
+)
 
 var _ interface {
 	io.ReadCloser
 	io.ReadSeeker
 } = (*SeekerBuffer)(nil)
 
-// Buffer is a ReadWriteCloser that supports seeking. It's intended to
+// SeekerBuffer is a ReadWriteCloser that supports seeking. It's intended to
 // replicate the functionality of bytes.Buffer that I use in my projects.
 //
 // Note that the seeking is limited to the read marker; all writes are
@@ -23,6 +26,7 @@ func NewSeekerBuffer(data []byte) *SeekerBuffer {
 	}
 }
 
+// Read reads up to len(p) bytes into p from the current read position.
 func (b *SeekerBuffer) Read(p []byte) (int, error) {
 	if b.pos >= int64(len(b.data)) {
 		return 0, io.EOF
@@ -30,29 +34,51 @@ func (b *SeekerBuffer) Read(p []byte) (int, error) {
 
 	n := copy(p, b.data[b.pos:])
 	b.pos += int64(n)
+
 	return n, nil
 }
 
+// Write appends the contents of p to the end of the buffer. It does not affect the read position.
 func (b *SeekerBuffer) Write(p []byte) (int, error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
+
 	b.data = append(b.data, p...)
+
 	return len(p), nil
 }
 
-// Seek sets the read pointer to pos.
+// Seek sets the offset for the next Read operation.
+// The offset is interpreted according to whence:
+// - io.SeekStart: relative to the beginning of the buffer
+// - io.SeekCurrent: relative to the current position
+// - io.SeekEnd: relative to the end of the buffer
+//
+// Returns an error if the resulting position is negative or if whence is invalid.
 func (b *SeekerBuffer) Seek(offset int64, whence int) (int64, error) {
+	var newPos int64
+
 	switch whence {
 	case io.SeekStart:
-		b.pos = offset
+		newPos = offset
 	case io.SeekEnd:
-		b.pos = int64(len(b.data)) + offset
+		newPos = int64(len(b.data)) + offset
 	case io.SeekCurrent:
-		b.pos += offset
+		newPos = b.pos + offset
+	default:
+		return 0, fmt.Errorf("invalid whence: %d", whence)
 	}
 
+	if newPos < 0 {
+		return 0, fmt.Errorf("invalid seek: resulting position %d is negative", newPos)
+	}
+
+	b.pos = newPos
 	return b.pos, nil
 }
 
-// Rewind resets the read pointer to 0.
+// Rewind resets the read position to 0.
 func (b *SeekerBuffer) Rewind() error {
 	if _, err := b.Seek(0, io.SeekStart); err != nil {
 		return err
@@ -67,12 +93,24 @@ func (b *SeekerBuffer) Close() error {
 	return nil
 }
 
+// Reset clears all the data out of the buffer and sets the read position to 0.
+func (b *SeekerBuffer) Reset() {
+	b.data = nil
+	b.pos = 0
+}
+
 // Len returns the length of data remaining to be read.
 func (b *SeekerBuffer) Len() int {
+	if b.pos >= int64(len(b.data)) {
+		return 0
+	}
 	return len(b.data[b.pos:])
 }
 
 // Bytes returns the underlying bytes from the current position.
 func (b *SeekerBuffer) Bytes() []byte {
+	if b.pos >= int64(len(b.data)) {
+		return []byte{}
+	}
 	return b.data[b.pos:]
 }

util/buffer/seeker_buffer_test.go

@@ -2,54 +2,384 @@ package buffer
 
 import (
 	"fmt"
-	"strings"
+	"io"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
-func noErrorT(t *testing.T, err error) {
+func TestNewSeekerBuffer(t *testing.T) {
-	if nil != err {
+	input := []byte{'a', 'b', 'c', 'd', 'e'}
-		t.Fatalf("%s", err)
+	expected := &SeekerBuffer{data: []byte{'a', 'b', 'c', 'd', 'e'}, pos: 0}
+	require.Equal(t, expected, NewSeekerBuffer(input))
+}
+
+func TestSeekerBuffer_Read(t *testing.T) {
+	tests := []struct {
+		name         string
+		data         []byte
+		initPos      int64
+		readBuf      []byte
+		expectedN    int
+		expectedData []byte
+		expectedErr  error
+		expectedPos  int64
+	}{
+		{
+			name:         "read with empty buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      []byte{},
+			expectedN:    0,
+			expectedData: []byte{},
+			expectedErr:  nil,
+			expectedPos:  0,
+		},
+		{
+			name:         "read with nil buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      nil,
+			expectedN:    0,
+			expectedData: nil,
+			expectedErr:  nil,
+			expectedPos:  0,
+		},
+		{
+			name:         "read full buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      make([]byte, 5),
+			expectedN:    5,
+			expectedData: []byte("hello"),
+			expectedErr:  nil,
+			expectedPos:  5,
+		},
+		{
+			name:         "read partial buffer",
+			data:         []byte("hello"),
+			initPos:      2,
+			readBuf:      make([]byte, 2),
+			expectedN:    2,
+			expectedData: []byte("ll"),
+			expectedErr:  nil,
+			expectedPos:  4,
+		},
+		{
+			name:         "read after end",
+			data:         []byte("hello"),
+			initPos:      5,
+			readBuf:      make([]byte, 5),
+			expectedN:    0,
+			expectedData: make([]byte, 5),
+			expectedErr:  io.EOF,
+			expectedPos:  5,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.data)
+			sb.pos = tt.initPos
+
+			n, err := sb.Read(tt.readBuf)
+
+			if tt.expectedErr != nil {
+				require.Equal(t, err, tt.expectedErr)
+			} else {
+				require.NoError(t, err)
+			}
+
+			require.Equal(t, tt.expectedN, n)
+			require.Equal(t, tt.expectedData, tt.readBuf)
+			require.Equal(t, tt.expectedPos, sb.pos)
+		})
 	}
 }
 
-func boolT(t *testing.T, cond bool, s ...string) {
+func TestSeekerBuffer_Write(t *testing.T) {
-	if !cond {
+	tests := []struct {
-		what := strings.Join(s, ", ")
+		name         string
-		if len(what) > 0 {
+		initialData  []byte
-			what = ": " + what
+		initialPos   int64
+		writeData    []byte
+		expectedData []byte
+		expectedN    int
+	}{
+		{
+			name:         "write empty slice",
+			initialData:  []byte("data"),
+			initialPos:   0,
+			writeData:    []byte{},
+			expectedData: []byte("data"),
+			expectedN:    0,
+		},
+		{
+			name:         "write nil slice",
+			initialData:  []byte("data"),
+			initialPos:   0,
+			writeData:    nil,
+			expectedData: []byte("data"),
+			expectedN:    0,
+		},
+		{
+			name:         "write to empty buffer",
+			initialData:  nil,
+			initialPos:   0,
+			writeData:    []byte("abc"),
+			expectedData: []byte("abc"),
+			expectedN:    3,
+		},
+		{
+			name:         "write to existing buffer",
+			initialData:  []byte("hello"),
+			initialPos:   0,
+			writeData:    []byte(" world"),
+			expectedData: []byte("hello world"),
+			expectedN:    6,
+		},
+		{
+			name:         "write after read",
+			initialData:  []byte("abc"),
+			initialPos:   2,
+			writeData:    []byte("XYZ"),
+			expectedData: []byte("abcXYZ"),
+			expectedN:    3,
+		},
 	}
-		t.Fatalf("assert.Bool failed%s", what)
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.initialData)
+			sb.pos = tt.initialPos
+
+			n, err := sb.Write(tt.writeData)
+			require.NoError(t, err)
+			require.Equal(t, tt.expectedN, n)
+			require.Equal(t, tt.expectedData, sb.data)
+			require.Equal(t, tt.initialPos, sb.pos)
+		})
 	}
 }
 
-func TestSeeking(t *testing.T) {
+func TestSeekerBuffer_Seek(t *testing.T) {
-	partA := []byte("hello, ")
+	tests := []struct {
-	partB := []byte("world!")
+		name        string
-
+		initialData []byte
-	buf := NewSeekerBuffer(partA)
+		initialPos  int64
-
+		offset      int64
-	boolT(t, buf.Len() == len(partA), fmt.Sprintf("on init: have length %d, want length %d", buf.Len(), len(partA)))
+		whence      int
-
+		expectedPos int64
-	b := make([]byte, 32)
+		expectedErr error
-
+	}{
-	n, err := buf.Read(b)
+		{
-	noErrorT(t, err)
+			name:        "seek with invalid whence",
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after reading 1: have length %d, want length 0", buf.Len()))
+			initialData: []byte("abcdef"),
-	boolT(t, n == len(partA), fmt.Sprintf("after reading 2: have length %d, want length %d", n, len(partA)))
+			initialPos:  0,
-
+			offset:      1,
-	n, err = buf.Write(partB)
+			whence:      12345,
-	noErrorT(t, err)
+			expectedPos: 0,
-	boolT(t, n == len(partB), fmt.Sprintf("after writing: have length %d, want length %d", n, len(partB)))
+			expectedErr: fmt.Errorf("invalid whence: %d", 12345),
-
+		},
-	n, err = buf.Read(b)
+		{
-	noErrorT(t, err)
+			name:        "seek negative from start",
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after rereading 1: have length %d, want length 0", buf.Len()))
+			initialData: []byte("abcdef"),
-	boolT(t, n == len(partB), fmt.Sprintf("after rereading 2: have length %d, want length %d", n, len(partB)))
+			initialPos:  0,
-
+			offset:      -1,
-	partsLen := len(partA) + len(partB)
+			whence:      io.SeekStart,
-	_ = buf.Rewind()
+			expectedPos: 0,
-	boolT(t, buf.Len() == partsLen, fmt.Sprintf("after rewinding: have length %d, want length %d", buf.Len(), partsLen))
+			expectedErr: fmt.Errorf("invalid seek: resulting position %d is negative", -1),
-
+		},
-	buf.Close()
+		{
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after closing, have length %d, want length 0", buf.Len()))
+			name:        "seek from start to 0",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      0,
+			whence:      io.SeekStart,
+			expectedPos: 0,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from start to 3",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      3,
+			whence:      io.SeekStart,
+			expectedPos: 3,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from end to -1 (last byte)",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      -1,
+			whence:      io.SeekEnd,
+			expectedPos: 5,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from current forward",
+			initialData: []byte("abcdef"),
+			initialPos:  2,
+			offset:      2,
+			whence:      io.SeekCurrent,
+			expectedPos: 4,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from current backward",
+			initialData: []byte("abcdef"),
+			initialPos:  4,
+			offset:      -2,
+			whence:      io.SeekCurrent,
+			expectedPos: 2,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek to end exactly",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      0,
+			whence:      io.SeekEnd,
+			expectedPos: 6,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek to out of range",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      2,
+			whence:      io.SeekEnd,
+			expectedPos: 8,
+			expectedErr: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.initialData)
+			sb.pos = tt.initialPos
+
+			newPos, err := sb.Seek(tt.offset, tt.whence)
+
+			if tt.expectedErr != nil {
+				require.Equal(t, tt.expectedErr, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tt.expectedPos, newPos)
+				require.Equal(t, tt.expectedPos, sb.pos)
+			}
+		})
+	}
+}
+
+func TestSeekerBuffer_Rewind(t *testing.T) {
+	buf := NewSeekerBuffer([]byte("hello world"))
+	buf.pos = 4
+
+	require.NoError(t, buf.Rewind())
+	require.Equal(t, []byte("hello world"), buf.data)
+	require.Equal(t, int64(0), buf.pos)
+}
+
+func TestSeekerBuffer_Close(t *testing.T) {
+	buf := NewSeekerBuffer([]byte("hello world"))
+	buf.pos = 2
+
+	require.NoError(t, buf.Close())
+	require.Nil(t, buf.data)
+	require.Equal(t, int64(0), buf.pos)
+}
+
+func TestSeekerBuffer_Reset(t *testing.T) {
+	buf := NewSeekerBuffer([]byte("hello world"))
+	buf.pos = 2
+
+	buf.Reset()
+	require.Nil(t, buf.data)
+	require.Equal(t, int64(0), buf.pos)
+}
+
+func TestSeekerBuffer_Len(t *testing.T) {
+	tests := []struct {
+		name     string
+		data     []byte
+		pos      int64
+		expected int
+	}{
+		{
+			name:     "full buffer",
+			data:     []byte("abcde"),
+			pos:      0,
+			expected: 5,
+		},
+		{
+			name:     "partial read",
+			data:     []byte("abcde"),
+			pos:      2,
+			expected: 3,
+		},
+		{
+			name:     "fully read",
+			data:     []byte("abcde"),
+			pos:      5,
+			expected: 0,
+		},
+		{
+			name:     "pos > len",
+			data:     []byte("abcde"),
+			pos:      10,
+			expected: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := NewSeekerBuffer(tt.data)
+			buf.pos = tt.pos
+			require.Equal(t, tt.expected, buf.Len())
+		})
+	}
+}
+
+func TestSeekerBuffer_Bytes(t *testing.T) {
+	tests := []struct {
+		name     string
+		data     []byte
+		pos      int64
+		expected []byte
+	}{
+		{
+			name:     "start of buffer",
+			data:     []byte("abcde"),
+			pos:      0,
+			expected: []byte("abcde"),
+		},
+		{
+			name:     "middle of buffer",
+			data:     []byte("abcde"),
+			pos:      2,
+			expected: []byte("cde"),
+		},
+		{
+			name:     "end of buffer",
+			data:     []byte("abcde"),
+			pos:      5,
+			expected: []byte{},
+		},
+		{
+			name:     "pos beyond end",
+			data:     []byte("abcde"),
+			pos:      10,
+			expected: []byte{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := NewSeekerBuffer(tt.data)
+			buf.pos = tt.pos
+			require.Equal(t, tt.expected, buf.Bytes())
+		})
+	}
 }

util/dns/cache.go

@@ -137,7 +137,7 @@ type cache struct {
 
 	opts Options
 
-	sync.RWMutex
+	mu sync.RWMutex
 }
 
 type cacheEntry struct {
@@ -171,7 +171,7 @@ func (c *cache) put(req string, res string) {
 		ttl = c.opts.MaxCacheTTL
 	}
 
-	c.Lock()
+	c.mu.Lock()
 	if c.entries == nil {
 		c.entries = make(map[string]cacheEntry)
 	}
@@ -207,7 +207,7 @@ func (c *cache) put(req string, res string) {
 	}
 
 	c.opts.Meter.Counter(semconv.CacheItemsTotal, "type", "dns").Inc()
-	c.Unlock()
+	c.mu.Unlock()
 }
 
 func (c *cache) get(req string) (res string) {
@@ -219,8 +219,8 @@ func (c *cache) get(req string) (res string) {
 		return ""
 	}
 
-	c.RLock()
+	c.mu.RLock()
-	defer c.RUnlock()
+	defer c.mu.RUnlock()
 
 	if c.entries == nil {
 		return ""

util/dns/conn.go

@@ -20,7 +20,7 @@ type dnsConn struct {
 	ibuf bytes.Buffer
 	obuf bytes.Buffer
 
-	sync.Mutex
+	mu sync.Mutex
 }
 
 type roundTripper func(ctx context.Context, req string) (res string, err error)
@@ -42,15 +42,15 @@ func (c *dnsConn) Read(b []byte) (n int, err error) {
 }
 
 func (c *dnsConn) Write(b []byte) (n int, err error) {
-	c.Lock()
+	c.mu.Lock()
-	defer c.Unlock()
+	defer c.mu.Unlock()
 	return c.ibuf.Write(b)
 }
 
 func (c *dnsConn) Close() error {
-	c.Lock()
+	c.mu.Lock()
 	cancel := c.cancel
-	c.Unlock()
+	c.mu.Unlock()
 
 	if cancel != nil {
 		cancel()
@@ -78,9 +78,9 @@ func (c *dnsConn) SetDeadline(t time.Time) error {
 }
 
 func (c *dnsConn) SetReadDeadline(t time.Time) error {
-	c.Lock()
+	c.mu.Lock()
 	c.deadline = t
-	c.Unlock()
+	c.mu.Unlock()
 	return nil
 }
 
@@ -90,8 +90,8 @@ func (c *dnsConn) SetWriteDeadline(_ time.Time) error {
 }
 
 func (c *dnsConn) drainBuffers(b []byte) (string, int, error) {
-	c.Lock()
+	c.mu.Lock()
-	defer c.Unlock()
+	defer c.mu.Unlock()
 
 	// drain the output buffer
 	if c.obuf.Len() > 0 {
@@ -119,8 +119,8 @@ func (c *dnsConn) drainBuffers(b []byte) (string, int, error) {
 }
 
 func (c *dnsConn) fillBuffer(b []byte, str string) (int, error) {
-	c.Lock()
+	c.mu.Lock()
-	defer c.Unlock()
+	defer c.mu.Unlock()
 	c.obuf.WriteByte(byte(len(str) >> 8))
 	c.obuf.WriteByte(byte(len(str)))
 	c.obuf.WriteString(str)
@@ -128,8 +128,8 @@ func (c *dnsConn) fillBuffer(b []byte, str string) (int, error) {
 }
 
 func (c *dnsConn) childContext() (context.Context, context.CancelFunc) {
-	c.Lock()
+	c.mu.Lock()
-	defer c.Unlock()
+	defer c.mu.Unlock()
 	if c.ctx == nil {
 		c.ctx, c.cancel = context.WithCancel(context.Background())
 	}

util/http/clienttracer.go

@@ -52,7 +52,7 @@ type clientTracer struct {
 	tr          tracer.Tracer
 	activeHooks map[string]context.Context
 	root        tracer.Span
-	mtx         sync.Mutex
+	mu          sync.Mutex
 }
 
 func NewClientTrace(ctx context.Context, tr tracer.Tracer) *httptrace.ClientTrace {
@@ -83,8 +83,8 @@ func NewClientTrace(ctx context.Context, tr tracer.Tracer) *httptrace.ClientTrac
 }
 
 func (ct *clientTracer) start(hook, spanName string, attrs ...interface{}) {
-	ct.mtx.Lock()
+	ct.mu.Lock()
-	defer ct.mtx.Unlock()
+	defer ct.mu.Unlock()
 
 	if hookCtx, found := ct.activeHooks[hook]; !found {
 		var sp tracer.Span
@@ -104,8 +104,8 @@ func (ct *clientTracer) start(hook, spanName string, attrs ...interface{}) {
 }
 
 func (ct *clientTracer) end(hook string, err error, attrs ...interface{}) {
-	ct.mtx.Lock()
+	ct.mu.Lock()
-	defer ct.mtx.Unlock()
+	defer ct.mu.Unlock()
 	if ctx, ok := ct.activeHooks[hook]; ok { // nolint:nestif
 		if span, ok := tracer.SpanFromContext(ctx); ok {
 			if err != nil {
@@ -136,8 +136,8 @@ func (ct *clientTracer) getParentContext(hook string) context.Context {
 }
 
 func (ct *clientTracer) span(hook string) (tracer.Span, bool) {
-	ct.mtx.Lock()
+	ct.mu.Lock()
-	defer ct.mtx.Unlock()
+	defer ct.mu.Unlock()
 	if ctx, ok := ct.activeHooks[hook]; ok {
 		return tracer.SpanFromContext(ctx)
 	}

util/id/id.go

@@ -2,12 +2,8 @@ package id
 
 import (
 	"crypto/rand"
-	"encoding/binary"
 	"errors"
-	"fmt"
-	"time"
 
-	uuidv8 "github.com/ash3in/uuidv8"
 	"github.com/google/uuid"
 	nanoid "github.com/matoous/go-nanoid"
 )
@@ -25,6 +21,7 @@ type Type int
 const (
 	TypeUnspecified Type = iota
 	TypeNanoid
+	TypeUUIDv7
 	TypeUUIDv8
 )
 
@@ -58,14 +55,14 @@ func (g *Generator) New() (string, error) {
 		}
 
 		return nanoid.Generate(g.opts.NanoidAlphabet, g.opts.NanoidSize)
-	case TypeUUIDv8:
+	case TypeUUIDv7:
-		timestamp := uint64(time.Now().UnixNano())
+		uid, err := uuid.NewV7()
-		clockSeq := make([]byte, 2)
+		if err != nil {
-		if _, err := rand.Read(clockSeq); err != nil {
+			return "", err
-			return "", fmt.Errorf("failed to generate random clock sequence: %w", err)
 		}
-		clockSeqValue := binary.BigEndian.Uint16(clockSeq) & 0x0FFF // Mask to 12 bits
+		return uid.String(), nil
-		return uuidv8.NewWithParams(timestamp, clockSeqValue, g.opts.UUIDNode[:], uuidv8.TimestampBits48)
+	case TypeUUIDv8:
+		return "", errors.New("unsupported uuid version v8")
 	}
 	return "", errors.New("invalid option, Type unspecified")
 }
@@ -82,16 +79,15 @@ func New(opts ...Option) (string, error) {
 		if options.NanoidSize <= 0 {
 			return "", errors.New("invalid option, NanoidSize must be positive integer")
 		}
-
 		return nanoid.Generate(options.NanoidAlphabet, options.NanoidSize)
-	case TypeUUIDv8:
+	case TypeUUIDv7:
-		timestamp := uint64(time.Now().UnixNano())
+		uid, err := uuid.NewV7()
-		clockSeq := make([]byte, 2)
+		if err != nil {
-		if _, err := rand.Read(clockSeq); err != nil {
+			return "", err
-			return "", fmt.Errorf("failed to generate random clock sequence: %w", err)
 		}
-		clockSeqValue := binary.BigEndian.Uint16(clockSeq) & 0x0FFF // Mask to 12 bits
+		return uid.String(), nil
-		return uuidv8.NewWithParams(timestamp, clockSeqValue, options.UUIDNode[:], uuidv8.TimestampBits48)
+	case TypeUUIDv8:
+		return "", errors.New("unsupported uuid version v8")
 	}
 
 	return "", errors.New("invalid option, Type unspecified")
@@ -145,7 +141,7 @@ func WithUUIDNode(node [6]byte) Option {
 // NewOptions returns new Options struct filled by opts
 func NewOptions(opts ...Option) Options {
 	options := Options{
-		Type:           TypeUUIDv8,
+		Type:           TypeUUIDv7,
 		NanoidAlphabet: DefaultNanoidAlphabet,
 		NanoidSize:     DefaultNanoidSize,
 		UUIDNode:       generatedNode,

util/ring/buffer.go

@@ -14,7 +14,7 @@ type Buffer struct {
 	vals    []*Entry
 	size    int
 
-	sync.RWMutex
+	mu sync.RWMutex
 }
 
 // Entry is ring buffer data entry
@@ -35,8 +35,8 @@ type Stream struct {
 
 // Put adds a new value to ring buffer
 func (b *Buffer) Put(v interface{}) {
-	b.Lock()
+	b.mu.Lock()
-	defer b.Unlock()
+	defer b.mu.Unlock()
 
 	// append to values
 	entry := &Entry{
@@ -63,8 +63,8 @@ func (b *Buffer) Put(v interface{}) {
 
 // Get returns the last n entries
 func (b *Buffer) Get(n int) []*Entry {
-	b.RLock()
+	b.mu.RLock()
-	defer b.RUnlock()
+	defer b.mu.RUnlock()
 
 	// reset any invalid values
 	if n > len(b.vals) || n < 0 {
@@ -80,8 +80,8 @@ func (b *Buffer) Get(n int) []*Entry {
 
 // Since returns the entries since a specific time
 func (b *Buffer) Since(t time.Time) []*Entry {
-	b.RLock()
+	b.mu.RLock()
-	defer b.RUnlock()
+	defer b.mu.RUnlock()
 
 	// return all the values
 	if t.IsZero() {
@@ -109,8 +109,8 @@ func (b *Buffer) Since(t time.Time) []*Entry {
 // Stream logs from the buffer
 // Close the channel when you want to stop
 func (b *Buffer) Stream() (<-chan *Entry, chan bool) {
-	b.Lock()
+	b.mu.Lock()
-	defer b.Unlock()
+	defer b.mu.Unlock()
 
 	entries := make(chan *Entry, 128)
 	id := id.MustNew()

util/stream/stream.go

@@ -24,7 +24,7 @@ type stream struct {
 	err     error
 	request *request
 
-	sync.RWMutex
+	mu sync.RWMutex
 }
 
 type request struct {
@@ -57,9 +57,9 @@ func (s *stream) Request() server.Request {
 func (s *stream) Send(v interface{}) error {
 	err := s.Stream.SendMsg(v)
 	if err != nil {
-		s.Lock()
+		s.mu.Lock()
 		s.err = err
-		s.Unlock()
+		s.mu.Unlock()
 	}
 	return err
 }
@@ -68,17 +68,17 @@ func (s *stream) Send(v interface{}) error {
 func (s *stream) Recv(v interface{}) error {
 	err := s.Stream.RecvMsg(v)
 	if err != nil {
-		s.Lock()
+		s.mu.Lock()
 		s.err = err
-		s.Unlock()
+		s.mu.Unlock()
 	}
 	return err
 }
 
 // Error returns error that stream holds
 func (s *stream) Error() error {
-	s.RLock()
+	s.mu.RLock()
-	defer s.RUnlock()
+	defer s.mu.RUnlock()
 	return s.err
 }
 

util/time/duration.go

@@ -6,7 +6,7 @@ import (
 	"strconv"
 	"time"
 
-	"gopkg.in/yaml.v3"
+	"github.com/goccy/go-yaml"
 )
 
 type Duration int64
@@ -58,9 +58,9 @@ func (d Duration) MarshalYAML() (interface{}, error) {
 	return time.Duration(d).String(), nil
 }
 
-func (d *Duration) UnmarshalYAML(n *yaml.Node) error {
+func (d *Duration) UnmarshalYAML(data []byte) error {
 	var v interface{}
-	if err := yaml.Unmarshal([]byte(n.Value), &v); err != nil {
+	if err := yaml.Unmarshal(data, &v); err != nil {
 		return err
 	}
 	switch value := v.(type) {

util/time/duration_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"gopkg.in/yaml.v3"
+	"github.com/goccy/go-yaml"
 )
 
 func TestMarshalYAML(t *testing.T) {

util/xpool/pool.go

@@ -6,18 +6,18 @@ import (
 	"strings"
 	"sync"
 	"sync/atomic"
-	"time"
 
 	"go.unistack.org/micro/v4/meter"
 	"go.unistack.org/micro/v4/semconv"
 )
 
-var (
+func unregisterMetrics(size int) {
-	pools   = make([]Statser, 0)
+	meter.DefaultMeter.Unregister(semconv.PoolGetTotal, "capacity", strconv.Itoa(size))
-	poolsMu sync.Mutex
+	meter.DefaultMeter.Unregister(semconv.PoolPutTotal, "capacity", strconv.Itoa(size))
-)
+	meter.DefaultMeter.Unregister(semconv.PoolMisTotal, "capacity", strconv.Itoa(size))
+	meter.DefaultMeter.Unregister(semconv.PoolRetTotal, "capacity", strconv.Itoa(size))
+}
 
-// Stats struct
 type Stats struct {
 	Get uint64
 	Put uint64
@@ -25,41 +25,13 @@ type Stats struct {
 	Ret uint64
 }
 
-// Statser provides buffer pool stats
-type Statser interface {
-	Stats() Stats
-	Cap() int
-}
-
-func init() {
-	go newStatsMeter()
-}
-
-func newStatsMeter() {
-	ticker := time.NewTicker(meter.DefaultMeterStatsInterval)
-	defer ticker.Stop()
-
-	for range ticker.C {
-		poolsMu.Lock()
-		for _, st := range pools {
-			stats := st.Stats()
-			meter.DefaultMeter.Counter(semconv.PoolGetTotal, "capacity", strconv.Itoa(st.Cap())).Set(stats.Get)
-			meter.DefaultMeter.Counter(semconv.PoolPutTotal, "capacity", strconv.Itoa(st.Cap())).Set(stats.Put)
-			meter.DefaultMeter.Counter(semconv.PoolMisTotal, "capacity", strconv.Itoa(st.Cap())).Set(stats.Mis)
-			meter.DefaultMeter.Counter(semconv.PoolRetTotal, "capacity", strconv.Itoa(st.Cap())).Set(stats.Ret)
-		}
-		poolsMu.Unlock()
-	}
-}
-
-var (
-	_ Statser = (*BytePool)(nil)
-	_ Statser = (*BytesPool)(nil)
-	_ Statser = (*StringsPool)(nil)
-)
-
 type Pool[T any] struct {
 	p   *sync.Pool
+	get *atomic.Uint64
+	put *atomic.Uint64
+	mis *atomic.Uint64
+	ret *atomic.Uint64
+	c   int
 }
 
 func (p Pool[T]) Put(t T) {
@@ -70,37 +42,82 @@ func (p Pool[T]) Get() T {
 	return p.p.Get().(T)
 }
 
-func NewPool[T any](fn func() T) Pool[T] {
+func NewPool[T any](fn func() T, size int) Pool[T] {
-	return Pool[T]{
+	p := Pool[T]{
-		p: &sync.Pool{
+		c:   size,
+		get: &atomic.Uint64{},
+		put: &atomic.Uint64{},
+		mis: &atomic.Uint64{},
+		ret: &atomic.Uint64{},
+	}
+
+	p.p = &sync.Pool{
 		New: func() interface{} {
+			p.mis.Add(1)
 			return fn()
 		},
-		},
 	}
+
+	meter.DefaultMeter.Gauge(semconv.PoolGetTotal, func() float64 {
+		return float64(p.get.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolPutTotal, func() float64 {
+		return float64(p.put.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolMisTotal, func() float64 {
+		return float64(p.mis.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolRetTotal, func() float64 {
+		return float64(p.ret.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	return p
 }
 
 type BytePool struct {
 	p   *sync.Pool
-	get uint64
+	get *atomic.Uint64
-	put uint64
+	put *atomic.Uint64
-	mis uint64
+	mis *atomic.Uint64
-	ret uint64
+	ret *atomic.Uint64
 	c   int
 }
 
 func NewBytePool(size int) *BytePool {
-	p := &BytePool{c: size}
+	p := &BytePool{
+		c:   size,
+		get: &atomic.Uint64{},
+		put: &atomic.Uint64{},
+		mis: &atomic.Uint64{},
+		ret: &atomic.Uint64{},
+	}
 	p.p = &sync.Pool{
 		New: func() interface{} {
-			atomic.AddUint64(&p.mis, 1)
+			p.mis.Add(1)
 			b := make([]byte, 0, size)
 			return &b
 		},
 	}
-	poolsMu.Lock()
+
-	pools = append(pools, p)
+	meter.DefaultMeter.Gauge(semconv.PoolGetTotal, func() float64 {
-	poolsMu.Unlock()
+		return float64(p.get.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolPutTotal, func() float64 {
+		return float64(p.put.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolMisTotal, func() float64 {
+		return float64(p.mis.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolRetTotal, func() float64 {
+		return float64(p.ret.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
 	return p
 }
 
@@ -110,49 +127,73 @@ func (p *BytePool) Cap() int {
 
 func (p *BytePool) Stats() Stats {
 	return Stats{
-		Put: atomic.LoadUint64(&p.put),
+		Put: p.put.Load(),
-		Get: atomic.LoadUint64(&p.get),
+		Get: p.get.Load(),
-		Mis: atomic.LoadUint64(&p.mis),
+		Mis: p.mis.Load(),
-		Ret: atomic.LoadUint64(&p.ret),
+		Ret: p.ret.Load(),
 	}
 }
 
 func (p *BytePool) Get() *[]byte {
-	atomic.AddUint64(&p.get, 1)
+	p.get.Add(1)
 	return p.p.Get().(*[]byte)
 }
 
 func (p *BytePool) Put(b *[]byte) {
-	atomic.AddUint64(&p.put, 1)
+	p.put.Add(1)
 	if cap(*b) > p.c {
-		atomic.AddUint64(&p.ret, 1)
+		p.ret.Add(1)
 		return
 	}
 	*b = (*b)[:0]
 	p.p.Put(b)
 }
 
+func (p *BytePool) Close() {
+	unregisterMetrics(p.c)
+}
+
 type BytesPool struct {
 	p   *sync.Pool
-	get uint64
+	get *atomic.Uint64
-	put uint64
+	put *atomic.Uint64
-	mis uint64
+	mis *atomic.Uint64
-	ret uint64
+	ret *atomic.Uint64
 	c   int
 }
 
 func NewBytesPool(size int) *BytesPool {
-	p := &BytesPool{c: size}
+	p := &BytesPool{
+		c:   size,
+		get: &atomic.Uint64{},
+		put: &atomic.Uint64{},
+		mis: &atomic.Uint64{},
+		ret: &atomic.Uint64{},
+	}
 	p.p = &sync.Pool{
 		New: func() interface{} {
-			atomic.AddUint64(&p.mis, 1)
+			p.mis.Add(1)
 			b := bytes.NewBuffer(make([]byte, 0, size))
 			return b
 		},
 	}
-	poolsMu.Lock()
+
-	pools = append(pools, p)
+	meter.DefaultMeter.Gauge(semconv.PoolGetTotal, func() float64 {
-	poolsMu.Unlock()
+		return float64(p.get.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolPutTotal, func() float64 {
+		return float64(p.put.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolMisTotal, func() float64 {
+		return float64(p.mis.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
+	meter.DefaultMeter.Gauge(semconv.PoolRetTotal, func() float64 {
+		return float64(p.ret.Load())
+	}, "capacity", strconv.Itoa(p.c))
+
 	return p
 }
 
@@ -162,10 +203,10 @@ func (p *BytesPool) Cap() int {
 
 func (p *BytesPool) Stats() Stats {
 	return Stats{
-		Put: atomic.LoadUint64(&p.put),
+		Put: p.put.Load(),
-		Get: atomic.LoadUint64(&p.get),
+		Get: p.get.Load(),
-		Mis: atomic.LoadUint64(&p.mis),
+		Mis: p.mis.Load(),
-		Ret: atomic.LoadUint64(&p.ret),
+		Ret: p.ret.Load(),
 	}
 }
 
@@ -174,34 +215,43 @@ func (p *BytesPool) Get() *bytes.Buffer {
 }
 
 func (p *BytesPool) Put(b *bytes.Buffer) {
+	p.put.Add(1)
 	if (*b).Cap() > p.c {
-		atomic.AddUint64(&p.ret, 1)
+		p.ret.Add(1)
 		return
 	}
 	b.Reset()
 	p.p.Put(b)
 }
 
+func (p *BytesPool) Close() {
+	unregisterMetrics(p.c)
+}
+
 type StringsPool struct {
 	p   *sync.Pool
-	get uint64
+	get *atomic.Uint64
-	put uint64
+	put *atomic.Uint64
-	mis uint64
+	mis *atomic.Uint64
-	ret uint64
+	ret *atomic.Uint64
 	c   int
 }
 
 func NewStringsPool(size int) *StringsPool {
-	p := &StringsPool{c: size}
+	p := &StringsPool{
+		c:   size,
+		get: &atomic.Uint64{},
+		put: &atomic.Uint64{},
+		mis: &atomic.Uint64{},
+		ret: &atomic.Uint64{},
+	}
 	p.p = &sync.Pool{
 		New: func() interface{} {
-			atomic.AddUint64(&p.mis, 1)
+			p.mis.Add(1)
 			return &strings.Builder{}
 		},
 	}
-	poolsMu.Lock()
+
-	pools = append(pools, p)
-	poolsMu.Unlock()
 	return p
 }
 
@@ -211,24 +261,28 @@ func (p *StringsPool) Cap() int {
 
 func (p *StringsPool) Stats() Stats {
 	return Stats{
-		Put: atomic.LoadUint64(&p.put),
+		Put: p.put.Load(),
-		Get: atomic.LoadUint64(&p.get),
+		Get: p.get.Load(),
-		Mis: atomic.LoadUint64(&p.mis),
+		Mis: p.mis.Load(),
-		Ret: atomic.LoadUint64(&p.ret),
+		Ret: p.ret.Load(),
 	}
 }
 
 func (p *StringsPool) Get() *strings.Builder {
-	atomic.AddUint64(&p.get, 1)
+	p.get.Add(1)
 	return p.p.Get().(*strings.Builder)
 }
 
 func (p *StringsPool) Put(b *strings.Builder) {
-	atomic.AddUint64(&p.put, 1)
+	p.put.Add(1)
 	if b.Cap() > p.c {
-		atomic.AddUint64(&p.ret, 1)
+		p.ret.Add(1)
 		return
 	}
 	b.Reset()
 	p.p.Put(b)
 }
+
+func (p *StringsPool) Close() {
+	unregisterMetrics(p.c)
+}