Add retries

client/options.go

@@ -16,6 +16,7 @@ type Options struct {
 	Selector    selector.Selector
 	Transport   transport.Transport
 	Wrappers    []Wrapper
+	Retries     int
 
 	// Other options to be used by client implementations
 	Options map[string]string
@@ -40,6 +41,44 @@ type RequestOptions struct {
 	Options map[string]string
 }
 
+func newOptions(options ...Option) Options {
+	opts := Options{
+		Codecs: make(map[string]codec.NewCodec),
+	}
+
+	for _, o := range options {
+		o(&opts)
+	}
+
+	if opts.Retries == 0 {
+		opts.Retries = 1
+	}
+
+	if len(opts.ContentType) == 0 {
+		opts.ContentType = defaultContentType
+	}
+
+	if opts.Broker == nil {
+		opts.Broker = broker.DefaultBroker
+	}
+
+	if opts.Registry == nil {
+		opts.Registry = registry.DefaultRegistry
+	}
+
+	if opts.Selector == nil {
+		opts.Selector = selector.NewSelector(
+			selector.Registry(opts.Registry),
+		)
+	}
+
+	if opts.Transport == nil {
+		opts.Transport = transport.DefaultTransport
+	}
+
+	return opts
+}
+
 // Broker to be used for pub/sub
 func Broker(b broker.Broker) Option {
 	return func(o *Options) {
@@ -89,6 +128,13 @@ func Wrap(w Wrapper) Option {
 	}
 }
 
+// Number of retries when making the request
+func Retries(i int) Option {
+	return func(o *Options) {
+		o.Retries = i
+	}
+}
+
 // Call Options
 
 func WithSelectOption(so selector.SelectOption) CallOption {

client/rpc_client.go

@@ -9,7 +9,6 @@ import (
 	"github.com/micro/go-micro/codec"
 	c "github.com/micro/go-micro/context"
 	"github.com/micro/go-micro/errors"
-	"github.com/micro/go-micro/registry"
 	"github.com/micro/go-micro/selector"
 	"github.com/micro/go-micro/transport"
 
@@ -24,35 +23,7 @@ type rpcClient struct {
 func newRpcClient(opt ...Option) Client {
 	var once sync.Once
 
-	opts := Options{
+	opts := newOptions(opt...)
-		Codecs: make(map[string]codec.NewCodec),
-	}
-
-	for _, o := range opt {
-		o(&opts)
-	}
-
-	if len(opts.ContentType) == 0 {
-		opts.ContentType = defaultContentType
-	}
-
-	if opts.Broker == nil {
-		opts.Broker = broker.DefaultBroker
-	}
-
-	if opts.Registry == nil {
-		opts.Registry = registry.DefaultRegistry
-	}
-
-	if opts.Selector == nil {
-		opts.Selector = selector.NewSelector(
-			selector.Registry(opts.Registry),
-		)
-	}
-
-	if opts.Transport == nil {
-		opts.Transport = transport.DefaultTransport
-	}
 
 	rc := &rpcClient{
 		once: once,
@@ -177,6 +148,7 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 		return errors.InternalServerError("go.micro.client", err.Error())
 	}
 
+	for i := 0; i < r.opts.Retries; i++ {
 		node, err := next()
 		if err != nil && err == selector.ErrNotFound {
 			return errors.NotFound("go.micro.client", err.Error())
@@ -191,6 +163,13 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 
 		err = r.call(ctx, address, request, response)
 		r.opts.Selector.Mark(request.Service(), node, err)
+
+		// if the call succeeded lets bail early
+		if err == nil {
+			return nil
+		}
+	}
+
 	return err
 }
 
@@ -211,6 +190,9 @@ func (r *rpcClient) Stream(ctx context.Context, request Request, opts ...CallOpt
 		return nil, errors.InternalServerError("go.micro.client", err.Error())
 	}
 
+	var stream Streamer
+
+	for i := 0; i < r.opts.Retries; i++ {
 		node, err := next()
 		if err != nil && err == selector.ErrNotFound {
 			return nil, errors.NotFound("go.micro.client", err.Error())
@@ -223,8 +205,15 @@ func (r *rpcClient) Stream(ctx context.Context, request Request, opts ...CallOpt
 			address = fmt.Sprintf("%s:%d", address, node.Port)
 		}
 
-	stream, err := r.stream(ctx, address, request)
+		stream, err = r.stream(ctx, address, request)
 		r.opts.Selector.Mark(request.Service(), node, err)
+
+		// bail early if succeeds
+		if err == nil {
+			return stream, nil
+		}
+	}
+
 	return stream, err
 }