MMORPGs, some MOBAs like League of Legends or even StarCraft 2 usually force you to pick a server. Usually they are US, EU and SEA, in MMORPGs many per location. I can see that that was necessary a few years ago, but now with the advent of AWS and similar offerings that allow you to seamlessly scale your "server-power", why are there still separate servers?
My train of thought is like this (using Star Wars: The Old Republic as an example): - You are always on one planet, an isolated "instance" from other planets. - If there are too many people on one planet, SW:TOR creates a new instance of the world and puts players in there. - If you leave the world / switch instances you have a loading-screen
So why can't the game create an instance for this planet. This instance (and only this one) has your current data in its database and manages x players. As soon as x-50 players are on this instance, a new server will fire up and new people will spawn on that instance. The 50 spots are reserved for switching to your group, etc.
There could be an instance for all three major regions to keep the latency low, but it would allow you to still play with other players from i.e. SEA if you can live with a 140ms delay (which is still nothing imho).
Whenever you switch an instance or travel to another world, your current server gives all your data to the next server, making sure you don't need one big centralized database. You could still have one that gets updates periodically for analysis purposes.
When you log off or the servers loses connection, the data could then be transferred into a massive database that is optimized for storing the data. The instance servers can then be optimized for high throughput.
Is there any particular reason this will not work? Are there other problems I am missing?