Add response header timeouts (#9170)

- Add conservative timeouts upto 3 minutes
  for internode communication
- Add aggressive timeouts of 30 seconds
  for gateway communication

Fixes #9105
Fixes #8732
Fixes #8881
Fixes #8376
Fixes #9028

cmd/generic-handlers.go

@@ -1,5 +1,5 @@
 /*
- * MinIO Cloud Storage, (C) 2015, 2016, 2017 MinIO, Inc.
+ * MinIO Cloud Storage, (C) 2015-2020 MinIO, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -721,7 +721,7 @@ func (f bucketForwardingHandler) ServeHTTP(w http.ResponseWriter, r *http.Reques
 func setBucketForwardingHandler(h http.Handler) http.Handler {
 	fwd := handlers.NewForwarder(&handlers.Forwarder{
 		PassHost:     true,
-		RoundTripper: NewCustomHTTPTransport(),
+		RoundTripper: NewGatewayHTTPTransport(),
 		Logger: func(err error) {
 			logger.LogIf(context.Background(), err)
 		},