SLA in cloud computing architectures: A comprehensive study

Abstract

Cloud computing, the model for providing on-demand access to a pool of shared resources with minimum provider interference, is emerging as a substitute to common IT infrastructure. As increasing numbers of cloud consumers dispatch their workloads to cloud providers, Service Level Agreement (SLA) between consumers and providers becomes of paramount importance to guarantee that service quality is preserved at satisfactory levels regardless of the dynamic nature of the cloud environment. SLA contains an explanation of the agreed service, parameters of the level of service, the guarantees regarding the Quality of Service, arrangements and cures for all cases of violations. In this paper, we provide a study about the general structure of SLA, its components, the management processes (in particular SLA monitoring), SLA lifecycle, and pricing. Then, we explore the importance of SLA for cloud computing services related to both the cloud user and the service provider including the differences between SLA for cloud services and other Web services. Finally, we present a comparison between the current major cloud computing service providers in terms of SLA’s.