Availability analysis of cloud computing centers

Accurate availability and performance analysis are important requirements to guarantee quality of services (QoS) for cloud users. In this paper, we integrate an availability model in overall analytical sub-models of cloud system. Each sub-model captures a specific aspect of cloud centers. The key performance metrics such as task blocking probability and total delay incurred on user tasks are obtained. Our results can be used by an admission control to prevent the cloud center from entering unstable regime of operation. The results also reveal practical insights into capacity planning for cloud computing centers.