Beyond proxy_pass

I have a situation where I have a very high write intensive site in
nginx. This site aggregates GPS positions for transit from a high
amount of devices.

The incoming traffic generates push notifications with the push_module
from slack.net (Leo)

I need to get nginx to send the same packet it receives to a
development server so that we can in essence fork the traffic so the
second server can make it’s own set of push notifications to have live
http activity but completely sandboxed from the production site.

I’ve got the two packt books and have been going through them and am
using proxy_pass already o serve JSON across domains in productions
but can’t seem to get proxy_pass to send to the development server
successfully.

What’s the best way to fork or mirror https requests to two locations
like this?

Brian Loomis