Efficient scalability through layered monitoring and event processing

Cloud computing is a paradigm that aims to transform computer, storage and network resources into a utility. As more applications are deployed on cloud environments, one of the main requirements refers to efficient scalability during the application execution. In this paper we present two mechanisms that aim at addressing this requirement: an adaptable two layer monitoring mechanism and an event processing framework. We evaluate the effectiveness of these mechanisms through a set of experiments on a large scale multi-cloud facility. The latter poses challenges with respect to time-constrained execution of applications, since the aforementioned mechanisms need to collect and analyse information from geographically distributed sites, and trigger scaling decisions during the real-time application execution. The experimentation outcomes demonstrate the value of the presented mechanisms, both in terms of efficient scalability and with respect to the introduced overhead on the infrastructure.