Using service level agreements for optimising cloud infrastructure services

Current Cloud environments are offered to their customers in a best effort approach. Instead of guarantees a statistical uptime expectation is communicated to the user with minimal compensations in case of unexpected downtime. In contrast, a service provider intending e.g. to extend his own resources dynamically with Cloud resources in case of peak demands of his customers needs a reliable Service Level Agreement with the Cloud infrastructure provider. This Service Level Agreement must cover aspects like cost, security, legal requirements for data-placement, eco-efficiency and more. The European project OPTIMIS is focussing on optimisation of cloud infrastructure services meeting demands from service providers, e.g. when public and private Clouds are federated in different configurations. This paper describes the approach of OPTIMIS for negotiating and creating Service Level Agreements between infrastructure providers and service providers.