Reliability aware scheduling in cloud computing

Cloud computing infrastructure encompasses many design challenges. Dealing with unreliability is one of the important design challenges in cloud computing platforms as we have a variety of services available for a variety of clients. In this paper, we present a model for the reliability assessment of the cloud infrastructures (computing nodes mostly virtual machines). This reliability assessment mechanism helps to do the scheduling on cloud infrastructure and perform fault tolerance on the basis of the reliability values acquired during reliability assessment. In our model, every compute instance (virtual machine in PaaS or physical processing node in IaaS) have reliability values associated with them. The system assesses the reliability for different types of applications. We have different mechanism to assess the reliability of general applications and real time applications. For real time applications, we have time based reliability assessment algorithms. All the algorithms are more convergent towards failures. If a compute instance passes, the reliability of the compute instance may increase or remain constant depending upon the algorithm. In the case of a failure, reliability decreases at a faster rate.