Predicting Cloud Performance for HPC Applications: A User-Oriented Approach
Cloud computing enables end users to execute high-performance computing applications by renting the required computing power. This pay-for-use approach enables small enterprises and startups to run HPC-related businesses with a significant saving in capital investment and a short time to market. When deploying an application in the cloud, the users may a) fail to understand the interactions of the application with the software layers implementing the cloud system, b) be unaware of some hardware details of the cloud system, and c) fail to understand how sharing part of the cloud system with other users might degrade application performance. These misunderstandings may lead the users to select suboptimal cloud configurations in terms of cost or performance. To aid the users in selecting the optimal cloud configuration for their applications, we suggest that the cloud provider generate a prediction model for the provided system. We propose applying machine-learning techniques to generate this prediction model. First, the cloud provider profiles a set of training applications by means of a hardware-independent profiler and then executes these applications on a set of training cloud configurations to collect actual performance values. The prediction model is trained to learn the dependencies of actual performance data on the application profile and cloud configuration parameters. The advantage of using a hardware-independent profiler is that the cloud users and the cloud provider can analyze applications on different machines and interface with the same prediction model. We validate the proposed methodology for a cloud system implemented with OpenStack. We apply the prediction model to the NAS parallel benchmarks. The resulting relative error is below 15% and the Pareto optimal cloud configurations finally found when maximizing application speed and minimizing execution cost on the prediction model are also at most 15% away from the actual optimal solutions.