Modelling and verification of reconfigurable fault-tolerant and self-recovering systems in hybrid Clouds

Abstract

Hybrid Cloud environments allow the utilization of local resources in private Clouds with resources from public Clouds when needed. Such environments represent systems with high failure rates because they feature heterogeneous components, a large number of servers with intensive workload are built as complex architectures. For these reasons, the availability of such systems could be easily compromised if the failure of these heterogeneous components is not handled correctly, which may cause request rejection and frequent performance degradation. Providing highly reliable Cloud applications, in particular in a hybrid Cloud environment, is a challenging and critical research problem. Therefore, the question we address in this paper is how to provision resources to user requests in the presence of failures in a hybrid Cloud environment. To this end, we propose a reconfigurable formal model of the hybrid Cloud architecture, then we utilize instantiations of this model, simulation and real-time execution runs to estimate different performance metrics related to fault detection and self-recovery strategies in hybrid Cloud. Our approach is based on the combination of the model-based and the probabilistic approaches.