Wouldn't you have to have an internet database for the players levels and such then? How could all of the servers access the same data and rewrite it at once?
Also, the same person logs on on two different servers, with the same database. What happens?
1. Each ID that enters gets it's own database. Then they only need to access them when a player changes.
2. It would auto kick the person who joins last.
Basically, the system would work like this.
There are 5 servers. 4 out of the 5 have passwords so random players can't join them. ID 20399 joins the one without the password. The server then creates a database for 20399. If the player levels up, then the server will access the database for that ID and update it. If the player changes to one of the other servers, the database updates the database to say that he is in this other server. Then that server is in charge of managing the database. If the player disconnects at any time, the database updates the player's latest stats, what server the player is in, and the position of that player. That way, when the player connects to the server without the password, it looks in the database to check what server it was in. If the player was in a different server, than the one without the password, it auto-reconnects to that server. Then the player spawns in the same position and with the same stats and inv.