Microsoft® SQL Server 2012 Unleashed

Server Instance Isolation

By design, you may want to isolate applications (such as SQL Server’s applications and their databases) away from each other to mitigate the risk of such an application causing another to fail.

Plain and simple, you should never put applications in each other’s way if you don’t have to. The only things that might force you to load up a single server with all your applications would be expensive licensing costs for each server’s software and perhaps hardware scarcity (strict limitations to the number of servers available for all applications). A classic example occurs when a company loads up a single SQL Server instance with between two and eight applications and their associated databases. The problem is that the applications ...