Low Cost Quality Aware Multi-tier Application Hosting on the Amazon Cloud

Public cloud providers offer a variety of services and resources enabling users to host their applications. In order to determine the set of resources that will best minimize hosting costs while simultaneously meeting performance requirements, cloud users must be aware of the cost-performance tradeoffs of the available resources. This is particularly true of multi-tier Web applications using dynamic scaling strategies to sustain specific response time requirements. In this paper, we provide a cost-performance analysis of multiple scale out strategies using the three most economically feasible Amazon EC2 compute resources (micro, small, and medium virtual machine instances) for a typical multi-tier Web application. We find that the special CPU allocation policy of the micro instance makes it especially suitable for satisfying Web application performance requirements at minimal cost on the Amazon cloud.