The first thing you want to do when preparing a Windows Server AppFabric environment for scale-out is to prepare a fully functional base installation.
The base installation is simple, but will vary slightly from the standalone design covered in Chapter 1, Installing Windows Server AppFabric because we'll need to separate the application server—which will handle hosting- and the database server which will provide persistence and monitoring support. In addition to provisioning each of these servers with the requisite Windows Server AppFabric components, we will also want to ensure that the application layer can talk to the monitoring and persistence stores that will reside on separate servers.
In addition, the security model will also vary from what you might be accustomed to because we'll want to shift from a purely local security model to a domain model since among other things, more than one application server will be communicating with the SQL Server...