Galactic War "Metagame"

Different players should be able to play on different maps during the same galactic war.

No, as I said, michael7050 was talking about a single game(like a 1v1) taking place across more than one system, that is what HE thought the Galactic War was.

In his vision, the sever would have to simulate all the systems because they are part of the same 'instance'.

Obviously for a Galactic War that is in line with Uber's comments you could not need to simulate all the systems at once, just the ones being used at any given time and even then individual games could be farmed out to different servers even.

Mike

What about building tanks and stuff on planets? What about resource collection?

Pretty sure that (in the context of devoting some CPU time) every planet will need to be loaded at the same time.

But not every system.

Only systems that have been fought on... so we expect that number to grow as time goes on.

Depending on the physics used you might need to load every system (when using n-body physics) or only those that have factories / units in them (because you can calculate the position of a planet on its orbit with velocity, position and delta time).

But if each one is only used during a battle, and then saved when the battle is done.

Why would you need to have them all loaded?

Because you cant predict how planets move in an n-body system. Only standard satellite gravity works that way. So you have to recalculate all the positions of the stellar objects every tick. I once tried using integration, it fails horribly if the time span allows one planet to move further than about 45°.

Why would that matter once the game stops?

Wow I hadn't really contemplated GW for single player, now I'm real excited

Who is talking about stopping the game? That only happens when one faction or clan or whatever won. And you definitely don't want to remove your base once it is done, because your commander is still there and should not be left unprotected.
About leaving systems loaded, if someone just threw an asteroid at your planet, and you were able to flee right before it hit, how embarrassing would it be if you came back and found yourself immediately destroyed by said asteroid (to be clear, it might even be a player who totally didn't know that someone was just destroying an asteroid). Or if you were able to view the system first, if nothing would be moving you wouldn't know if the asteroid is in orbit or smashing the planet.

depending on how it would be implemented, I guess there would be only 3 real types of systems:
a) untouched, as in no one tried to play there and represents the initial state
b) currently contested, active game session where a game server needs to be provided
c) finished fight, some kind of last game state/savegame needs to be stored to be accessed again if moved into state b) again, symbolic/meta info describing the system would be enough on a galaxy level

if you would set up the game similar to this, only the case b) requires actually loading star systems, which could be done on independent game servers.

I don't think more information on the galaxy level would be needed or viable and that would just cover the galaxy level as a kind of high level game lobby and leaves the "game" part still to be designed.

Only that the system must be loaded in state c too as there's still a commander and a base there.
And you're right that you only need information about the planets not the full data, but you have to quick load it once a planetary collision occurs.

why should it be loaded in c? After the fight is finished the commander left that system and on a planetary system all that is needed is a "picture" of the systems last state. I don't think it's needed or wished to have full real time infos on planetary positions etc, because you are right, then you would have to simulate this for practically all systems which would hinder scaling quite a bit.

We already found out that the commander does stay in the system until you order him to move. Besides you can't conquer systems if you destroy everything after the battle and your commander disappears to god knows where.

at some point the step from live game to meta game has to be made. This transformation would create a symbolic/meta representation of the last state and would describe the end of the last game session. Also from then on the commander is more a board game pin than a RTS unit. It doesn't really matter if he is officially still in the system other than for his role in the meta game part. True, there is some abstraction and loss of detail involved, but otherwise it will be difficult to combine those different levels.

the usual disclaimer:
That would be my approach without knowledge of the actual planning and development on Uebers side.