Merge pull request #281 from micro/retry

retry only on timeout or internal server error

client/client.go

@@ -68,7 +68,7 @@ var (
 	// DefaultBackoff is the default backoff function for retries
 	DefaultBackoff = exponentialBackoff
 	// DefaultRetry is the default check-for-retry function for retries
-	DefaultRetry = alwaysRetry
+	DefaultRetry = RetryOnError
 	// DefaultRetries is the default number of times a request is tried
 	DefaultRetries = 1
 	// DefaultRequestTimeout is the default request timeout

client/retry.go

@@ -2,12 +2,34 @@ package client
 
 import (
 	"context"
+
+	"github.com/micro/go-micro/errors"
 )
 
 // note that returning either false or a non-nil error will result in the call not being retried
 type RetryFunc func(ctx context.Context, req Request, retryCount int, err error) (bool, error)
 
-// always retry on error
+// RetryAlways always retry on error
-func alwaysRetry(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+func RetryAlways(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
 	return true, nil
 }
+
+// RetryOnError retries a request on a 500 or timeout error
+func RetryOnError(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+	if err == nil {
+		return false, nil
+	}
+
+	e := errors.Parse(err.Error())
+	if e == nil {
+		return false, nil
+	}
+
+	switch e.Code {
+	// retry on timeout or internal server error
+	case 408, 500:
+		return true, nil
+	default:
+		return false, nil
+	}
+}

client/rpc_client_test.go

@@ -2,10 +2,10 @@ package client
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"testing"
 
+	"github.com/micro/go-micro/errors"
 	"github.com/micro/go-micro/registry"
 	"github.com/micro/go-micro/registry/mock"
 	"github.com/micro/go-micro/selector"
@@ -69,7 +69,7 @@ func TestCallRetry(t *testing.T) {
 		return func(ctx context.Context, addr string, req Request, rsp interface{}, opts CallOptions) error {
 			called++
 			if called == 1 {
-				return errors.New("retry request")
+				return errors.InternalServerError("test.error", "retry request")
 			}
 
 			// don't do the call