I’m making system like client-server. There’s two possibilities: to log in as user or admin. On one of the machines, e.g. superadmin’s machine is storing main database. There’s option to log in as administrator from any machine and to get datas from this main database.
But I’ve problem – what if this machine’ll be broke? This db should be available all the time, but putting the db with the same datas on each machine it doesn’t make sense.
I think about chosing proportional amounts of machines that will be store copies of main database: e.g. 2 on 10 computers in LAN.
Is there any better idea? Or better proportions?
SQL Server supports both failover clustering which it sounds like you want here and replication which you could also use to maintain multiple instances.
in a failover cluster if one instance goes down the clients won’t notice it, in a replication scenario you have multiple sql servers, each client is tied to one sql server, if one goes down then all the clients using that server will have a problem (of course, you could go ahead and custom make your own failover implementation on top of replicated sql servers, but I would highly recommend you to use the technology provided by Microsoft instead)