Cost- and performance-based evaluation of cloud-based disaster recovery

Cloud platforms offer not only the capacity to facilitate effective and scalable services for third-party applications and business solutions, but also present an opportunity to implement intricate disaster recovery strategies. For instance, a Chief Technical Officer may opt to maintain operations on private systems in order to effectively manage costs, privacy, and security, while leveraging at the same time the cloud as an autonomous and immediate disaster recovery support. This objective can be achieved by building a second leg of the IT system that functions as an online cold or hot spare, manages workload peaks, or handles a portion of the workload under normal conditions. To assess the cost-effectiveness of such solutions, appropriate models are essential to examine the trade-offs and explore the parameter space of possible alternatives. The contribution of this paper is twofold. Firstly, it defines a multiformalism model for the design and evaluation of cloud-based recovery setups; secondly, it studies the time and the effects of transient management on costs, including losses due to a decreased capacity to serve requests.