Dynamic Server Provisioning to Minimize Cost in an laaS Cloud

摘要

Cloud computing holds the exciting potential of elastically scaling computation to match time-varying demand, thus eliminating the need to provision for peak demand to satisfy response-time requirements. Moreover, cloud vendors often offer several commitment levels for their machine instances (e.g., users can choose to pay an upfront premium for the discounted hourly usage price). Because cost is a major concern that may limit the cloud adoption, two key challenges are to determine (a) the number of machines to provision and (b) the commitment level at which the machine instances should be acquired, to minimize cost while satisfying response-time targets. This paper address the above two challenges in an Infrastructure-as-a-Service (IaaS) cloud. Our simulations with real Web server load traces reveal that our techniques offer a cost reduction between 13% and 29% (21% on average) under Amazon EC2 pricing models.