A Scheduling Strategy Based on Redundancy of Service Requests on IaaS Providers

The improvement in virtualisation technologies, as well as higher data transmission rates and the popularisation of the Internet contributed to strengthen the cloud computing. This paradigm attracts more and more users to consume, and providers to offer services through the pay-as-you-go model. The users can benefit from the clouds by receiving high availability, cost reduction, load balancing, and better fault tolerance when deploying cloud services across several cloud providers instead of using a single service provider. However, the variety of charging models, quality of service (QoS), and monetary costs of virtual machines, makes it difficult to the customer to choose the best resource charging models to deploy applications. In this paper we propose a redundancy strategy based on the tenancy level among requests in order to decrease the scheduling cost and maintain QoS levels along different IaaS charging models. The strategy is modelled as an integer linear program (ILP) to compute the lowest cost when utilising virtual machines. Simulations show that the proposed approach computes schedules with smaller costs than alternative approaches.