A common scenario we see is customers want to use Auto-Scaling groups to keep their cloud costs as low as possible. Keep only the minimal amount of VMs needed to handle an expected load. For example, you expect to have 1000 requests a second. You set up the necessary VMs to handle 1200 requests a second. When the number of requests gets to 900/second you add on some additional machines to handle that load.
When that happens, how can you add a machine using Auto Scaling groups, get the lastest code deployed and add that machine into a load balancer? What about when you no longer need the machine? How can you handle that?