1 files changed, 48 insertions, 28 deletions

diff --git a/vendor/github.com/aws/aws-sdk-go/aws/client/default_retryer.go b/vendor/github.com/aws/aws-sdk-go/aws/client/default_retryer.go
index e25a460..a397b0d 100644
--- a/vendor/github.com/aws/aws-sdk-go/aws/client/default_retryer.go
+++ b/vendor/github.com/aws/aws-sdk-go/aws/client/default_retryer.go
@@ -1,11 +1,11 @@
 package client
 
 import (
-	"math/rand"
-	"sync"
+	"strconv"
 	"time"
 
 	"github.com/aws/aws-sdk-go/aws/request"
+	"github.com/aws/aws-sdk-go/internal/sdkrand"
 )
 
 // DefaultRetryer implements basic retry logic using exponential backoff for
@@ -30,25 +30,27 @@ func (d DefaultRetryer) MaxRetries() int {
 	return d.NumMaxRetries
 }
 
-var seededRand = rand.New(&lockedSource{src: rand.NewSource(time.Now().UnixNano())})
-
 // RetryRules returns the delay duration before retrying this request again
 func (d DefaultRetryer) RetryRules(r *request.Request) time.Duration {
 	// Set the upper limit of delay in retrying at ~five minutes
 	minTime := 30
 	throttle := d.shouldThrottle(r)
 	if throttle {
+		if delay, ok := getRetryDelay(r); ok {
+			return delay
+		}
+
 		minTime = 500
 	}
 
 	retryCount := r.RetryCount
-	if retryCount > 13 {
-		retryCount = 13
-	} else if throttle && retryCount > 8 {
+	if throttle && retryCount > 8 {
 		retryCount = 8
+	} else if retryCount > 13 {
+		retryCount = 13
 	}
 
-	delay := (1 << uint(retryCount)) * (seededRand.Intn(minTime) + minTime)
+	delay := (1 << uint(retryCount)) * (sdkrand.SeededRand.Intn(minTime) + minTime)
 	return time.Duration(delay) * time.Millisecond
 }
 
@@ -60,7 +62,7 @@ func (d DefaultRetryer) ShouldRetry(r *request.Request) bool {
 		return *r.Retryable
 	}
 
-	if r.HTTPResponse.StatusCode >= 500 {
+	if r.HTTPResponse.StatusCode >= 500 && r.HTTPResponse.StatusCode != 501 {
 		return true
 	}
 	return r.IsErrorRetryable() || d.shouldThrottle(r)
@@ -68,29 +70,47 @@ func (d DefaultRetryer) ShouldRetry(r *request.Request) bool {
 
 // ShouldThrottle returns true if the request should be throttled.
 func (d DefaultRetryer) shouldThrottle(r *request.Request) bool {
-	if r.HTTPResponse.StatusCode == 502 ||
-		r.HTTPResponse.StatusCode == 503 ||
-		r.HTTPResponse.StatusCode == 504 {
-		return true
+	switch r.HTTPResponse.StatusCode {
+	case 429:
+	case 502:
+	case 503:
+	case 504:
+	default:
+		return r.IsErrorThrottle()
 	}
-	return r.IsErrorThrottle()
-}
 
-// lockedSource is a thread-safe implementation of rand.Source
-type lockedSource struct {
-	lk  sync.Mutex
-	src rand.Source
+	return true
 }
 
-func (r *lockedSource) Int63() (n int64) {
-	r.lk.Lock()
-	n = r.src.Int63()
-	r.lk.Unlock()
-	return
+// This will look in the Retry-After header, RFC 7231, for how long
+// it will wait before attempting another request
+func getRetryDelay(r *request.Request) (time.Duration, bool) {
+	if !canUseRetryAfterHeader(r) {
+		return 0, false
+	}
+
+	delayStr := r.HTTPResponse.Header.Get("Retry-After")
+	if len(delayStr) == 0 {
+		return 0, false
+	}
+
+	delay, err := strconv.Atoi(delayStr)
+	if err != nil {
+		return 0, false
+	}
+
+	return time.Duration(delay) * time.Second, true
 }
 
-func (r *lockedSource) Seed(seed int64) {
-	r.lk.Lock()
-	r.src.Seed(seed)
-	r.lk.Unlock()
+// Will look at the status code to see if the retry header pertains to
+// the status code.
+func canUseRetryAfterHeader(r *request.Request) bool {
+	switch r.HTTPResponse.StatusCode {
+	case 429:
+	case 503:
+	default:
+		return false
+	}
+
+	return true
 }