Background: I'm working on a project where we are upgrading from Tridion 2013 to Web 8.5. We currently have several sites set up in the existing Tridion 2013 implementation that connect to several different Content Delivery databases. The Deployer is configured to send Content to these various different databases, depending on certain conditions about where things are located in the CMS.
This all works fine for Tridion 2013, as each web application either connects directly to one of these Content Delivery databases or it incorporates Content published to a file system. In Web 8.5, however, it's not clear how we can configure our web applications to connect to the appropriate Content Delivery database. We should be able to configure the Web 8.5 Deployer to send content to several different databases, similar to the current Tridion 2013 setup. However, how can our web apps know which Content Delivery database contains the Content it consumes, considering our CD environment has one single Discovery Service entry point? Is there some routing logic handled by the Discovery Service? Or do we need multiple Discovery Services (i.e. one for each Content Delivery database)?