Graph seems to be returning invalid retry-after header values. Fiddler traces show I'm receiving 429 Too Many Requests error codes from batched requests sent to the v1.0/$batch endpoint, but the Retry-After header I'm receiving are all decimals (0.249, 0.124 etc). HTTP spec says positive integers or timestamps are valid, but I'm receiving a decimal. Not sure how to handle it! I get an exception when calling
new HttpResponseMessage().Headers.Add("Retry-After","0.256");
but absolutely fine when I call
new HttpResponseMessage().Headers.Add("Retry-After","120");
as an example of a valid Retry-After header.