The Amazon cloud offers horizontal auto-scaling. This feature spins up (or down) VM instances to meet the load requirements. However, it doesn't offer 'vertical scaling'.  Vertical scaling is when you change the size of an instance (e.g., micro to large). Vertically Challenged is an auto-scale service for compute instances on AWS. It uses CloudWatch to determine when an instance should have its size adjusted. The primary problem with resizing instances is that configuration data is normally lost when you spin it back up. For example, the instance may have been connected to a load balancer, or part of a VPC, etc. This service attempts to restore the configuration as it was in the initial instance.