I have an application that consists of a Windows Phone client sending HTTP requests to a Python server hosted in Google App Engine. In the GAE log, I see that I often receive multiple identical requests from the same client within a few milliseconds (see below). I never saw this behavior when testing the client in my development environment. Nonetheless I realize that this is probably error in my code, but my question is:
Can any part of the infrastructure (the mobile network, the internet, the google app engine itself) cause requests to be duplicated?
And if so, a follow on question is: are there best practices to minimize this?
It’s really not possible for the network to duplicate HTTP requests. It can duplicate IP datagrams with misconfigured routing, but the TCP layer filters duplicate IP datagrams so that the end to end connection only sees one TCP stream. App engine might reuse TCP ports without the standard time to wait for the previous TCP connection to die for performance purposes, but I still don’t think duplicate packets would survive from the three-way TCP handshake used to initialize connections.