Brief intro 1: about me:
I have this question in the back of my mind for a really long period of time, and I am currently very busy in establishing the offline aspects of the game(will take more than a year from now). So, honestly, I haven't found the time to learn properly about the ins and outs of networked game programming. Thus, I need just general answers so that I can estimate what game designs are possible to make.
Brief intro 2: about the type of game:
Without going into great details, the game is an action multiplayer online game that is safe to assume to have the latency requirements that are roughly half as demanding as a typical First Person Shooter. For instance, let's say a shooter is great at lower than 40-to-50 RTT, then my game is roughly at 100-140 RTT would be good for the gameplay. But with a lot of caveats that I won't delve into in this intro. But every caveats warrants specific challenge on the game design proper.
Assume the game is running on an AWS or a Google server.
Assume a game session is running on a single server, with a few hundreds of players.
Assume another game session is running on another server.
Now let's further assume that we need to swap players from one server to another server, on the fly.
This means that the player will probably be disconnected from one server, and reconnect to the next server mid game session!
[A] How long could it take to do so (switch a client connection from one server to another), assuming the RTT between each party and the other is say 100ms?
[B] Finally, will this practice be substantially faster if the transfer happens within one AWS infrastructure in one city, or one building? Am I even allowed to gain that level of control over the service?