Cost-Efficient and Application SLA-Aware Client Side Request Scheduling in an

Providers of applications deployed in an Infrastructure-as-a-Service cloud permanently face the decision of whether it is more cost-efficient to scale up (i.e., rent more resources from the cloud) or to delay incoming requests, even though doing so may lead to dissatisfied customers and broken service level agreements. This decision is further complicated by the fact that not all customers have the same agreements, and not all requests require the same amount of resources devoted to them. In this paper, we present an approach for optimally scheduling incoming requests to virtual computing resources in the cloud, so that the sum of payments for resources and loss incurred by service level agreement violations is minimized. We discuss our approach based on an illustrative use case. Furthermore, we present a numerical evaluation based on real-life request data, which shows that our agreement-aware algorithm improves upon earlier work, which does not take service level agreements into account. I