Added backoff retry

internal/internal.go

@@ -0,0 +1,23 @@
+package internal
+
+import (
+	"math/rand"
+	"time"
+)
+
+const retryBackoff = 8 * time.Millisecond
+
+// Retry backoff with jitter sleep to prevent overloaded conditions during intervals
+// https://www.awsarchitectureblog.com/2015/03/backoff.html
+func RetryBackoff(retry int, maxRetryBackoff time.Duration) time.Duration {
+	if retry < 0 {
+		retry = 0
+	}
+
+	backoff := retryBackoff << uint(retry)
+	if backoff > maxRetryBackoff {
+		backoff = maxRetryBackoff
+	}
+
+	return time.Duration(rand.Int63n(int64(backoff)))
+}