Sample application periodically makes many http and https requests to servers.
And there are a lots of “400” status codes in the log-files of our web servers (nginx). There are much more such bad requests than “good” requests.
The same problem if you do the http(s) request from QML using XMLHttpRequest.

Reasons - our app often opens “empty” connection, i mean that it establishes tcp connection with web server and do not send anything to this socket.

Why it`s a big problem.

If you need to perform 3 - 5 requests on your web server that you expect to be opened (and closed) 3 - 5 compounds, but on the basis of the described problem occurs following application of 1 to 5 additional connections.
In this case, the audience applications ~ 200,000 unique users each perform 1 - 2 https request every 5 - 10 minutes.
We have up to 80% of empty connections to the Web server and a lot of overhead.

How to reproduce (see attached sample qt project files).