An Empirical Study on the Discrepancy between Performance Testing
Results from Virtual and Physical EnvironmentsMuhammad Moiz Arif Large software systems often undergo performance tests to ensure their capability to handle expected loads. These performance tests often consume large amounts of computing resources and time in order to exercise the system extensively and build confidence on results. Making it worse, the ever evolving field environments require frequent updates to the performance testing environment. In practice, virtual machines (VMs) are widely exploited to provide flexible and less costly environments for performance tests. However, the use of VMs may introduce confounding overhead (e.g., a higher than expected memory utilization with unstable I/O traffic) to the testing environment and lead to unrealistic performance testing results. Yet, little research has studied the impact on test results of using VMs in performance testing activities.In this thesis, we evaluate the discrepancy between the performance testing results from virtual and physical environments. We perform a case study on two open source systems -namely Dell DVD Store (DS2) and CloudStore. We conduct the same performance tests in both virtual and physical environments and compare the performance testing results based on the three aspects that are typically examined for performance testing results: 1) single performance metric (e.g. CPU usage from virtual environment vs. CPU usage from physical environment), 2) the relationship between two performance metrics (e.g. correlation between CPU usage and I/O traffic) and iii
Contents
List of Figures xi
List of Tables xiiiList of Tables Spearman's rank correlation coefficients and p-values of the highlighted