John Wiley & Sons
Though Cloud computing itself has many open problems, researchers in the field have already made the leap to envision Inter-Cloud computing. Their goal is to achieve better overall Quality of Service (QoS), reliability and cost efficiency by utilizing multiple clouds. Inter-Cloud research is still in its infancy and the body of knowledge in the area has not been well defined yet. In this paper, the authors propose and motivate taxonomies for Inter-Cloud architectures and application brokering mechanisms. They present a detailed survey of the state of the art in terms of both academic and industry developments (20 projects) and they fit each project onto the discussed taxonomies.