Middleware Django statistics
I believe that performance is extremely important on websites. 
I would consider any delay at all due to requests to a logging server unacceptable.
I think you should move the logging call to a background thread,
and return the response to the user as quickly as possible.

As usual, it's probably a good idea to put a cap on the maximum number of background threads. It could be even just one thread doing all the logging tasks in sequence.

Other than this, the code looks fine to me.
It's simple and not easy to pick on.