refactor: unify selector filter (#2277)

* unify selector

Co-authored-by: caoguoliang01 <caoguoliang01@bilibili.com>
Co-authored-by: chenzhihui <zhihui_chen@foxmail.com>

selector/default_selector.go

@@ -9,7 +9,6 @@ import (
 type Default struct {
 	NodeBuilder WeightedNodeBuilder
 	Balancer    Balancer
-	Filters     []Filter
 
 	nodes atomic.Value
 }
@@ -27,16 +26,13 @@ func (d *Default) Select(ctx context.Context, opts ...SelectOption) (selected No
 	for _, o := range opts {
 		o(&options)
 	}
-	if len(d.Filters) > 0 || len(options.Filters) > 0 {
+	if len(options.NodeFilters) > 0 {
 		newNodes := make([]Node, len(nodes))
 		for i, wc := range nodes {
 			newNodes[i] = wc
 		}
-		for _, f := range d.Filters {
+		for _, filter := range options.NodeFilters {
-			newNodes = f(ctx, newNodes)
+			newNodes = filter(ctx, newNodes)
-		}
-		for _, f := range options.Filters {
-			newNodes = f(ctx, newNodes)
 		}
 		candidates = make([]WeightedNode, len(newNodes))
 		for i, n := range newNodes {
@@ -74,7 +70,6 @@ func (d *Default) Apply(nodes []Node) {
 type DefaultBuilder struct {
 	Node     WeightedNodeBuilder
 	Balancer BalancerBuilder
-	Filters  []Filter
 }
 
 // Build create builder
@@ -82,6 +77,5 @@ func (db *DefaultBuilder) Build() Selector {
 	return &Default{
 		NodeBuilder: db.Node,
 		Balancer:    db.Balancer.Build(),
-		Filters:     db.Filters,
 	}
 }

selector/filter.go

@@ -2,5 +2,5 @@ package selector
 
 import "context"
 
-// Filter is select filter.
+// NodeFilter is select filter.
-type Filter func(context.Context, []Node) []Node
+type NodeFilter func(context.Context, []Node) []Node

selector/filter/version.go

@@ -7,7 +7,7 @@ import (
 )
 
 // Version is version filter.
-func Version(version string) selector.Filter {
+func Version(version string) selector.NodeFilter {
 	return func(_ context.Context, nodes []selector.Node) []selector.Node {
 		newNodes := nodes[:0]
 		for _, n := range nodes {

selector/global.go

@@ -0,0 +1,13 @@
+package selector
+
+var globalSelector Builder
+
+// GlobalSelector returns global selector builder.
+func GlobalSelector() Builder {
+	return globalSelector
+}
+
+// SetGlobalSelector set global selector builder.
+func SetGlobalSelector(builder Builder) {
+	globalSelector = builder
+}

selector/options.go

@@ -2,15 +2,15 @@ package selector
 
 // SelectOptions is Select Options.
 type SelectOptions struct {
-	Filters []Filter
+	NodeFilters []NodeFilter
 }
 
 // SelectOption is Selector option.
 type SelectOption func(*SelectOptions)
 
-// WithFilter with filter options
+// WithNodeFilter with filter options
-func WithFilter(fn ...Filter) SelectOption {
+func WithNodeFilter(fn ...NodeFilter) SelectOption {
 	return func(opts *SelectOptions) {
-		opts.Filters = fn
+		opts.NodeFilters = fn
 	}
 }

selector/p2c/p2c.go

@@ -19,20 +19,11 @@ const (
 
 var _ selector.Balancer = &Balancer{}
 
-// WithFilter with select filters
-func WithFilter(filters ...selector.Filter) Option {
-	return func(o *options) {
-		o.filters = filters
-	}
-}
-
 // Option is random builder option.
 type Option func(o *options)
 
 // options is random builder options
-type options struct {
+type options struct{}
-	filters []selector.Filter
-}
 
 // New creates a p2c selector.
 func New(opts ...Option) selector.Selector {
@@ -95,7 +86,6 @@ func NewBuilder(opts ...Option) selector.Builder {
 		opt(&option)
 	}
 	return &selector.DefaultBuilder{
-		Filters:  option.filters,
 		Balancer: &Builder{},
 		Node:     &ewma.Builder{},
 	}

selector/p2c/p2c_test.go

@@ -16,7 +16,7 @@ import (
 )
 
 func TestWrr3(t *testing.T) {
-	p2c := New(WithFilter(filter.Version("v2.0.0")))
+	p2c := New()
 	var nodes []selector.Node
 	for i := 0; i < 3; i++ {
 		addr := fmt.Sprintf("127.0.0.%d:8080", i)
@@ -41,7 +41,7 @@ func TestWrr3(t *testing.T) {
 			d := time.Duration(rand.Intn(500)) * time.Millisecond
 			lk.Unlock()
 			time.Sleep(d)
-			n, done, err := p2c.Select(context.Background())
+			n, done, err := p2c.Select(context.Background(), selector.WithNodeFilter(filter.Version("v2.0.0")))
 			if err != nil {
 				t.Errorf("expect %v, got %v", nil, err)
 			}
@@ -92,7 +92,7 @@ func TestEmpty(t *testing.T) {
 }
 
 func TestOne(t *testing.T) {
-	p2c := New(WithFilter(filter.Version("v2.0.0")))
+	p2c := New()
 	var nodes []selector.Node
 	for i := 0; i < 1; i++ {
 		addr := fmt.Sprintf("127.0.0.%d:8080", i)
@@ -106,7 +106,7 @@ func TestOne(t *testing.T) {
 			}))
 	}
 	p2c.Apply(nodes)
-	n, done, err := p2c.Select(context.Background())
+	n, done, err := p2c.Select(context.Background(), selector.WithNodeFilter(filter.Version("v2.0.0")))
 	if err != nil {
 		t.Errorf("expect %v, got %v", nil, err)
 	}

selector/random/random.go

@@ -15,20 +15,11 @@ const (
 
 var _ selector.Balancer = &Balancer{} // Name is balancer name
 
-// WithFilter with select filters
-func WithFilter(filters ...selector.Filter) Option {
-	return func(o *options) {
-		o.filters = filters
-	}
-}
-
 // Option is random builder option.
 type Option func(o *options)
 
 // options is random builder options
-type options struct {
+type options struct{}
-	filters []selector.Filter
-}
 
 // Balancer is a random balancer.
 type Balancer struct{}
@@ -56,7 +47,6 @@ func NewBuilder(opts ...Option) selector.Builder {
 		opt(&option)
 	}
 	return &selector.DefaultBuilder{
-		Filters:  option.filters,
 		Balancer: &Builder{},
 		Node:     &direct.Builder{},
 	}

selector/random/random_test.go

@@ -10,7 +10,7 @@ import (
 )
 
 func TestWrr(t *testing.T) {
-	random := New(WithFilter(filter.Version("v2.0.0")))
+	random := New()
 	var nodes []selector.Node
 	nodes = append(nodes, selector.NewNode(
 		"http",
@@ -31,7 +31,7 @@ func TestWrr(t *testing.T) {
 	random.Apply(nodes)
 	var count1, count2 int
 	for i := 0; i < 200; i++ {
-		n, done, err := random.Select(context.Background())
+		n, done, err := random.Select(context.Background(), selector.WithNodeFilter(filter.Version("v2.0.0")))
 		if err != nil {
 			t.Errorf("expect no error, got %v", err)
 		}

selector/selector.go

@@ -57,7 +57,7 @@ type DoneInfo struct {
 	// Response Error
 	Err error
 	// Response Metadata
-	ReplyMeta ReplyMeta
+	ReplyMD ReplyMD
 
 	// BytesSent indicates if any bytes have been sent to the server.
 	BytesSent bool
@@ -65,8 +65,8 @@ type DoneInfo struct {
 	BytesReceived bool
 }
 
-// ReplyMeta is Reply Metadata.
+// ReplyMD is Reply Metadata.
-type ReplyMeta interface {
+type ReplyMD interface {
 	Get(key string) string
 }
 

selector/selector_test.go

@@ -49,7 +49,7 @@ func (b *mockWeightedNodeBuilder) Build(n Node) WeightedNode {
 	return &mockWeightedNode{Node: n}
 }
 
-func mockFilter(version string) Filter {
+func mockFilter(version string) NodeFilter {
 	return func(_ context.Context, nodes []Node) []Node {
 		newNodes := nodes[:0]
 		for _, n := range nodes {
@@ -83,7 +83,6 @@ func (b *mockBalancer) Pick(ctx context.Context, nodes []WeightedNode) (selected
 func TestDefault(t *testing.T) {
 	builder := DefaultBuilder{
 		Node:     &mockWeightedNodeBuilder{},
-		Filters:  []Filter{mockFilter("v2.0.0")},
 		Balancer: &mockBalancerBuilder{},
 	}
 	selector := builder.Build()
@@ -109,7 +108,7 @@ func TestDefault(t *testing.T) {
 			Metadata:  map[string]string{"weight": "10"},
 		}))
 	selector.Apply(nodes)
-	n, done, err := selector.Select(context.Background(), WithFilter(mockFilter("v2.0.0")))
+	n, done, err := selector.Select(context.Background(), WithNodeFilter(mockFilter("v2.0.0")))
 	if err != nil {
 		t.Errorf("expect %v, got %v", nil, err)
 	}
@@ -137,7 +136,7 @@ func TestDefault(t *testing.T) {
 	done(context.Background(), DoneInfo{})
 
 	// no v3.0.0 instance
-	n, done, err = selector.Select(context.Background(), WithFilter(mockFilter("v3.0.0")))
+	n, done, err = selector.Select(context.Background(), WithNodeFilter(mockFilter("v3.0.0")))
 	if !errors.Is(ErrNoAvailable, err) {
 		t.Errorf("expect %v, got %v", ErrNoAvailable, err)
 	}
@@ -150,7 +149,7 @@ func TestDefault(t *testing.T) {
 
 	// apply zero instance
 	selector.Apply([]Node{})
-	n, done, err = selector.Select(context.Background(), WithFilter(mockFilter("v2.0.0")))
+	n, done, err = selector.Select(context.Background(), WithNodeFilter(mockFilter("v2.0.0")))
 	if !errors.Is(ErrNoAvailable, err) {
 		t.Errorf("expect %v, got %v", ErrNoAvailable, err)
 	}
@@ -163,7 +162,7 @@ func TestDefault(t *testing.T) {
 
 	// apply zero instance
 	selector.Apply(nil)
-	n, done, err = selector.Select(context.Background(), WithFilter(mockFilter("v2.0.0")))
+	n, done, err = selector.Select(context.Background(), WithNodeFilter(mockFilter("v2.0.0")))
 	if !errors.Is(ErrNoAvailable, err) {
 		t.Errorf("expect %v, got %v", ErrNoAvailable, err)
 	}

selector/wrr/wrr.go

@@ -15,20 +15,11 @@ const (
 
 var _ selector.Balancer = &Balancer{} // Name is balancer name
 
-// WithFilter with select filters
-func WithFilter(filters ...selector.Filter) Option {
-	return func(o *options) {
-		o.filters = filters
-	}
-}
-
 // Option is random builder option.
 type Option func(o *options)
 
 // options is random builder options
-type options struct {
+type options struct{}
-	filters []selector.Filter
-}
 
 // Balancer is a random balancer.
 type Balancer struct {
@@ -77,7 +68,6 @@ func NewBuilder(opts ...Option) selector.Builder {
 		opt(&option)
 	}
 	return &selector.DefaultBuilder{
-		Filters:  option.filters,
 		Balancer: &Builder{},
 		Node:     &direct.Builder{},
 	}

selector/wrr/wrr_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 func TestWrr(t *testing.T) {
-	wrr := New(WithFilter(filter.Version("v2.0.0")))
+	wrr := New()
 	var nodes []selector.Node
 	nodes = append(nodes, selector.NewNode(
 		"http",
@@ -32,7 +32,7 @@ func TestWrr(t *testing.T) {
 	wrr.Apply(nodes)
 	var count1, count2 int
 	for i := 0; i < 90; i++ {
-		n, done, err := wrr.Select(context.Background())
+		n, done, err := wrr.Select(context.Background(), selector.WithNodeFilter(filter.Version("v2.0.0")))
 		if err != nil {
 			t.Errorf("expect no error, got %v", err)
 		}

transport/grpc/balancer.go

@@ -1,59 +1,45 @@
 package grpc
 
 import (
-	"sync"
-
 	"github.com/go-kratos/kratos/v2/registry"
 	"github.com/go-kratos/kratos/v2/selector"
-	"github.com/go-kratos/kratos/v2/selector/p2c"
-	"github.com/go-kratos/kratos/v2/selector/random"
-	"github.com/go-kratos/kratos/v2/selector/wrr"
 	"github.com/go-kratos/kratos/v2/transport"
 
-	gBalancer "google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/base"
 	"google.golang.org/grpc/metadata"
 )
 
-var (
+const (
-	_ base.PickerBuilder = &Builder{}
+	balancerName = "selector"
-	_ gBalancer.Picker   = &Picker{}
+)
 
-	mu sync.Mutex
+var (
+	_ base.PickerBuilder = &balancerBuilder{}
+	_ balancer.Picker    = &balancerPicker{}
 )
 
 func init() {
-	// inject global grpc balancer
-	SetGlobalBalancer(random.Name, random.NewBuilder())
-	SetGlobalBalancer(wrr.Name, wrr.NewBuilder())
-	SetGlobalBalancer(p2c.Name, p2c.NewBuilder())
-}
-
-// SetGlobalBalancer set grpc balancer with scheme.
-func SetGlobalBalancer(scheme string, builder selector.Builder) {
-	mu.Lock()
-	defer mu.Unlock()
-
 	b := base.NewBalancerBuilder(
-		scheme,
+		balancerName,
-		&Builder{builder: builder},
+		&balancerBuilder{
+			builder: selector.GlobalSelector(),
+		},
 		base.Config{HealthCheck: true},
 	)
-	gBalancer.Register(b)
+	balancer.Register(b)
 }
 
-// Builder is grpc balancer builder.
+type balancerBuilder struct {
-type Builder struct {
 	builder selector.Builder
 }
 
 // Build creates a grpc Picker.
-func (b *Builder) Build(info base.PickerBuildInfo) gBalancer.Picker {
+func (b *balancerBuilder) Build(info base.PickerBuildInfo) balancer.Picker {
 	if len(info.ReadySCs) == 0 {
 		// Block the RPC until a new picker is available via UpdateState().
-		return base.NewErrPicker(gBalancer.ErrNoSubConnAvailable)
+		return base.NewErrPicker(balancer.ErrNoSubConnAvailable)
 	}
-
 	nodes := make([]selector.Node, 0)
 	for conn, info := range info.ReadySCs {
 		ins, _ := info.Address.Attributes.Value("rawServiceInstance").(*registry.ServiceInstance)
@@ -62,40 +48,40 @@ func (b *Builder) Build(info base.PickerBuildInfo) gBalancer.Picker {
 			subConn: conn,
 		})
 	}
-	p := &Picker{
+	p := &balancerPicker{
 		selector: b.builder.Build(),
 	}
 	p.selector.Apply(nodes)
 	return p
 }
 
-// Picker is a grpc picker.
+// balancerPicker is a grpc picker.
-type Picker struct {
+type balancerPicker struct {
 	selector selector.Selector
 }
 
 // Pick pick instances.
-func (p *Picker) Pick(info gBalancer.PickInfo) (gBalancer.PickResult, error) {
+func (p *balancerPicker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	var filters []selector.Filter
+	var filters []selector.NodeFilter
 	if tr, ok := transport.FromClientContext(info.Ctx); ok {
 		if gtr, ok := tr.(*Transport); ok {
-			filters = gtr.SelectFilters()
+			filters = gtr.NodeFilters()
 		}
 	}
 
-	n, done, err := p.selector.Select(info.Ctx, selector.WithFilter(filters...))
+	n, done, err := p.selector.Select(info.Ctx, selector.WithNodeFilter(filters...))
 	if err != nil {
-		return gBalancer.PickResult{}, err
+		return balancer.PickResult{}, err
 	}
 
-	return gBalancer.PickResult{
+	return balancer.PickResult{
 		SubConn: n.(*grpcNode).subConn,
-		Done: func(di gBalancer.DoneInfo) {
+		Done: func(di balancer.DoneInfo) {
 			done(info.Ctx, selector.DoneInfo{
 				Err:           di.Err,
 				BytesSent:     di.BytesSent,
 				BytesReceived: di.BytesReceived,
-				ReplyMeta:     Trailer(di.Trailer),
+				ReplyMD:       Trailer(di.Trailer),
 			})
 		},
 	}, nil
@@ -115,5 +101,5 @@ func (t Trailer) Get(k string) string {
 
 type grpcNode struct {
 	selector.Node
-	subConn gBalancer.SubConn
+	subConn balancer.SubConn
 }

transport/grpc/balancer_test.go

@@ -19,19 +19,10 @@ func TestTrailer(t *testing.T) {
 	}
 }
 
-func TestBalancerName(t *testing.T) {
-	o := &clientOptions{}
-
-	WithBalancerName("p2c")(o)
-	if !reflect.DeepEqual("p2c", o.balancerName) {
-		t.Errorf("expect %v, got %v", "p2c", o.balancerName)
-	}
-}
-
 func TestFilters(t *testing.T) {
 	o := &clientOptions{}
 
-	WithFilter(func(_ context.Context, nodes []selector.Node) []selector.Node {
+	WithNodeFilter(func(_ context.Context, nodes []selector.Node) []selector.Node {
 		return nodes
 	})(o)
 	if !reflect.DeepEqual(1, len(o.filters)) {

transport/grpc/client.go

@@ -10,7 +10,7 @@ import (
 	"github.com/go-kratos/kratos/v2/middleware"
 	"github.com/go-kratos/kratos/v2/registry"
 	"github.com/go-kratos/kratos/v2/selector"
-	"github.com/go-kratos/kratos/v2/selector/wrr"
+	"github.com/go-kratos/kratos/v2/selector/p2c"
 	"github.com/go-kratos/kratos/v2/transport"
 	"github.com/go-kratos/kratos/v2/transport/grpc/resolver/discovery"
 
@@ -23,6 +23,12 @@ import (
 	grpcmd "google.golang.org/grpc/metadata"
 )
 
+func init() {
+	if selector.GlobalSelector() == nil {
+		selector.SetGlobalSelector(p2c.NewBuilder())
+	}
+}
+
 // ClientOption is gRPC client option.
 type ClientOption func(o *clientOptions)
 
@@ -75,15 +81,8 @@ func WithOptions(opts ...grpc.DialOption) ClientOption {
 	}
 }
 
-// WithBalancerName with balancer name
+// WithNodeFilter with select filters
-func WithBalancerName(name string) ClientOption {
+func WithNodeFilter(filters ...selector.NodeFilter) ClientOption {
-	return func(o *clientOptions) {
-		o.balancerName = name
-	}
-}
-
-// WithFilter with select filters
-func WithFilter(filters ...selector.Filter) ClientOption {
 	return func(o *clientOptions) {
 		o.filters = filters
 	}
@@ -105,7 +104,7 @@ type clientOptions struct {
 	ints         []grpc.UnaryClientInterceptor
 	grpcOpts     []grpc.DialOption
 	balancerName string
-	filters      []selector.Filter
+	filters      []selector.NodeFilter
 }
 
 // Dial returns a GRPC connection.
@@ -121,7 +120,7 @@ func DialInsecure(ctx context.Context, opts ...ClientOption) (*grpc.ClientConn,
 func dial(ctx context.Context, insecure bool, opts ...ClientOption) (*grpc.ClientConn, error) {
 	options := clientOptions{
 		timeout:      2000 * time.Millisecond,
-		balancerName: wrr.Name,
+		balancerName: balancerName,
 	}
 	for _, o := range opts {
 		o(&options)
@@ -156,13 +155,13 @@ func dial(ctx context.Context, insecure bool, opts ...ClientOption) (*grpc.Clien
 	return grpc.DialContext(ctx, options.endpoint, grpcOpts...)
 }
 
-func unaryClientInterceptor(ms []middleware.Middleware, timeout time.Duration, filters []selector.Filter) grpc.UnaryClientInterceptor {
+func unaryClientInterceptor(ms []middleware.Middleware, timeout time.Duration, filters []selector.NodeFilter) grpc.UnaryClientInterceptor {
 	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
 		ctx = transport.NewClientContext(ctx, &Transport{
 			endpoint:    cc.Target(),
 			operation:   method,
 			reqHeader:   headerCarrier{},
-			filters:   filters,
+			nodeFilters: filters,
 		})
 		if timeout > 0 {
 			var cancel context.CancelFunc

transport/grpc/transport.go

@@ -14,7 +14,7 @@ type Transport struct {
 	operation   string
 	reqHeader   headerCarrier
 	replyHeader headerCarrier
-	filters     []selector.Filter
+	nodeFilters []selector.NodeFilter
 }
 
 // Kind returns the transport kind.
@@ -42,9 +42,9 @@ func (tr *Transport) ReplyHeader() transport.Header {
 	return tr.replyHeader
 }
 
-// SelectFilters returns the client select filters.
+// NodeFilters returns the client select filters.
-func (tr *Transport) SelectFilters() []selector.Filter {
+func (tr *Transport) NodeFilters() []selector.NodeFilter {
-	return tr.filters
+	return tr.nodeFilters
 }
 
 type headerCarrier metadata.MD

transport/http/client.go

@@ -16,10 +16,16 @@ import (
 	"github.com/go-kratos/kratos/v2/middleware"
 	"github.com/go-kratos/kratos/v2/registry"
 	"github.com/go-kratos/kratos/v2/selector"
-	"github.com/go-kratos/kratos/v2/selector/wrr"
+	"github.com/go-kratos/kratos/v2/selector/p2c"
 	"github.com/go-kratos/kratos/v2/transport"
 )
 
+func init() {
+	if selector.GlobalSelector() == nil {
+		selector.SetGlobalSelector(p2c.NewBuilder())
+	}
+}
+
 // DecodeErrorFunc is decode error func.
 type DecodeErrorFunc func(ctx context.Context, res *http.Response) error
 
@@ -43,7 +49,7 @@ type clientOptions struct {
 	decoder      DecodeResponseFunc
 	errorDecoder DecodeErrorFunc
 	transport    http.RoundTripper
-	selector     selector.Selector
+	nodeFilters  []selector.NodeFilter
 	discovery    registry.Discovery
 	middleware   []middleware.Middleware
 	block        bool
@@ -112,10 +118,10 @@ func WithDiscovery(d registry.Discovery) ClientOption {
 	}
 }
 
-// WithSelector with client selector.
+// WithNodeFilter with select filters
-func WithSelector(selector selector.Selector) ClientOption {
+func WithNodeFilter(filters ...selector.NodeFilter) ClientOption {
 	return func(o *clientOptions) {
-		o.selector = selector
+		o.nodeFilters = filters
 	}
 }
 
@@ -140,6 +146,7 @@ type Client struct {
 	r        *resolver
 	cc       *http.Client
 	insecure bool
+	selector selector.Selector
 }
 
 // NewClient returns an HTTP client.
@@ -151,7 +158,6 @@ func NewClient(ctx context.Context, opts ...ClientOption) (*Client, error) {
 		decoder:      DefaultResponseDecoder,
 		errorDecoder: DefaultErrorDecoder,
 		transport:    http.DefaultTransport,
-		selector:     wrr.New(),
 	}
 	for _, o := range opts {
 		o(&options)
@@ -166,10 +172,11 @@ func NewClient(ctx context.Context, opts ...ClientOption) (*Client, error) {
 	if err != nil {
 		return nil, err
 	}
+	selector := selector.GlobalSelector().Build()
 	var r *resolver
 	if options.discovery != nil {
 		if target.Scheme == "discovery" {
-			if r, err = newResolver(ctx, options.discovery, target, options.selector, options.block, insecure); err != nil {
+			if r, err = newResolver(ctx, options.discovery, target, selector, options.block, insecure); err != nil {
 				return nil, fmt.Errorf("[http client] new resolver failed!err: %v", options.endpoint)
 			}
 		} else if _, _, err := host.ExtractHostPort(options.endpoint); err != nil {
@@ -185,6 +192,7 @@ func NewClient(ctx context.Context, opts ...ClientOption) (*Client, error) {
 			Timeout:   options.timeout,
 			Transport: options.transport,
 		},
+		selector: selector,
 	}, nil
 }
 
@@ -276,7 +284,7 @@ func (client *Client) do(req *http.Request) (*http.Response, error) {
 			err  error
 			node selector.Node
 		)
-		if node, done, err = client.opts.selector.Select(req.Context()); err != nil {
+		if node, done, err = client.selector.Select(req.Context(), selector.WithNodeFilter(client.opts.nodeFilters...)); err != nil {
 			return nil, errors.ServiceUnavailable("NODE_NOT_FOUND", err.Error())
 		}
 		if client.insecure {

transport/http/client_test.go

@@ -182,13 +182,18 @@ func TestWithDiscovery(t *testing.T) {
 	}
 }
 
-func TestWithSelector(t *testing.T) {
+func TestWithNodeFilter(t *testing.T) {
-	ov := &selector.Default{}
+	ov := func(context.Context, []selector.Node) []selector.Node {
-	o := WithSelector(ov)
+		return []selector.Node{&selector.DefaultNode{}}
+	}
+	o := WithNodeFilter(ov)
 	co := &clientOptions{}
 	o(co)
-	if !reflect.DeepEqual(co.selector, ov) {
+	for _, n := range co.nodeFilters {
-		t.Errorf("expected selector to be %v, got %v", ov, co.selector)
+		ret := n(context.Background(), nil)
+		if len(ret) != 1 {
+			t.Errorf("expected node  length to be 1, got %v", len(ret))
+		}
 	}
 }