CloudFlex: Seamless scaling of enterprise applications into the cloud

This paper proposes and studies a system, called CloudFlex, which transparently taps cloud resources to serve application requests that exceed capacity of internal infrastructure. CloudFlex operates as a feedback control system with two key interacting components: load balancer and controller. We focus on operational optimality and stability of the system, highlight the tradeoffs between cost and responsiveness, and address important design considerations such as choke point detection that are critical in avoiding pathological system operations. For evaluation, we develop a prototype of CloudFlex on our testbed comprising servers of our enterprise data center and Amazon EC2 instances.