The problem If you often use HttpClient to call REST APIs or to transfer files, you may have been annoyed by the way this class handles request timeout. There are two major issues with timeout handling in HttpClient: The timeout is defined at the HttpClient level and applies to all requests made with this HttpClient; it would be more convenient to be able to specify a timeout individually for each request.
If you ever had to upload large volumes of data over HTTP, you probably ran into timeout issues. The default Timeout value for HttpWebRequest is 100 seconds, which means that if it takes more than that from the time you send the request headers to the time you receive the response headers, your request will fail. Obviously, if you’re uploading a large file, you need to increase that timeout… but to which value?