I am running a replica set mongo cluster in three regions, fronted by an application endpoint in each of those regions.
Technically, the application endpoints can talk to all endpoints in the mongo replica set, but reads (if using default read concern) should come from the “nearest” neighbor. I was thinking that it would be cool to visualize which applications are communicating with each other, and be able to “lightly sniff” those communications.
I SSHed into one of the machines, and sniffed its traffic to verify that reads were going to its nearest neighbor, but it would be super cool if there was an easy way to visualize the entire stack.