E9.2 Blue-Green Deployment

Does anyone have any detailed information on Oracle's recommendation for the Blue-Green deployment to allow minimum downtime tools upgrades? I read their "whitepaper" on this, but it didn't provide too many details, like how the servers were configured. Are they just using different sets of servers with different names, and switching the load balancer and OCM, or are they using some other method that allows the servers to maintain the same names and still be updated while on the network.