As Maury said I might have same issue , I remember we discussed by mail somewhere in April.
In my case I have the users that share the same DB, could be 1, could be 5, could be max 20, Them they connect locally to a Linux server that hosts that database and the files, so far I guess all ok until here.
Now I want to have a central server in a public location that will centralize all those boxes and keep the db in sync between central server and local servers, more like a backup location if you can say that way, in the same time if in case the Local server cannot be accessed due to some local restrictions maybe, to be able to access the main public one and fetch and update the data there. In my case as well each Box has to have independent database synced to the main server.
So I will have something like (Main server - Public, Master Node1, I guess) <--> Box (Master node for clients and secondary node for the Main server ) <--> Clients that need to access Box when in same network and Main server when outside or Box not reachable.
Now do you have an option for the Main server to be able to handle multiple databases, I guess on the same port, as if we start to forward ports for each Box, now we have 100 , but in the future if we reach to 100,000 boxes I guess it will be quite impossible to forward those ports, and for data security and rules, each DB has to stay independent so we cannot use the pro version in this case, unless we find a way to separate the data when requested or when one box leaves.
How do you mitigate the DB corruption as well ? and backups ?