Towards Availability

Abstract

With the on-demand ability of cloud computing, the performance requirement of a cloud application can be satisfied by adding a certain amount of computing resources to or removing some from the application in response to the workload fluctuation. However, the problem of the availability of application influenced by VM-based physical relative locations during resource scaling process is a challenge and has not been widely discussed yet. In this paper, the authors present a novel availability-based computing model to describe availability attribute of one application in the hierarchical topology of clouds. Moreover, the authors propose an availability-aware scaling mechanism by performing both vertical and horizontal resizing to explore how and where to allocate computing resource. Simulation results indicate that our model captured the availability of cloud applications properly and the proposed dynamic scaling approach achieves the objectives of meeting availability demands and minimizing the total cost.