backend/s3: Added 500 as retryErrorCode

The error code 500 Internal Error indicates that Amazon S3 is unable to handle the request at that time. The error code 503 Slow Down typically indicates that the requests to the S3 bucket are very high, exceeding the request rates described in Request Rate and Performance Guidelines.

Because Amazon S3 is a distributed service, a very small percentage of 5xx errors are expected during normal use of the service. All requests that return 5xx errors from Amazon S3 can and should be retried, so we recommend that applications making requests to Amazon S3 have a fault-tolerance mechanism to recover from these errors.

https://aws.amazon.com/premiumsupport/knowledge-center/http-5xx-errors-s3/

Author: mmatczuk

backend/s3/s3.go

@@ -908,7 +908,7 @@ func (f *Fs) Features() *fs.Features {
 // retryErrorCodes is a slice of error codes that we will retry
 // See: https://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
 var retryErrorCodes = []int{
-	// 409, // Conflict - various states that could be resolved on a retry
+	500, // Internal Server Error - "We encountered an internal error. Please try again."
 	503, // Service Unavailable/Slow Down - "Reduce your request rate"
 }