Interacting Stochastic Models Approach for Performability Analysis of IaaS Cloud

In this paper, we describe an analytical modeling approach for performability analysis of cloud provided services. We use infrastructure-as-a-service as an example of a cloud based service, where service availability and provisioning response delays are key service level agreements (SLAs) to users while cost reductions are important to service providers. A novelty of our approach is in reducing the complexity of the analysis by dividing the overall model into multiple interacting sub-models and then obtaining the overall solution by iteration over submodel solutions. This results in a high fidelity model that is scalable. We summarize our modeling approach, showcase our ongoing work through initial results and outline future avenues of research using such an approach.