Date of Award


Degree Name

MS in Computer Science


Computer Science


Phil Nico


Fifty percent of Fortune 500 companies trust Xen, an open-source bare-metal hypervisor, to virtualize their websites and mission critical services in the cloud. Providing superior fault tolerance, scalability, and migration, virtualization allows these companies to run several isolated operating systems simultaneously on the same physical server. These isolated operating systems, called virtual machines, require a virtual traffic guard to cooperate with one another. This guard known as the Credit2 scheduler along with the newest Xen hypervisor was recently developed to supersede the older schedulers. Since wasted CPU cycles can be costly, the Credit2 prototype must undergo significant performance validation before being released into production. Furthermore, leading commercial virtualization products, including VMWare and Microsoft Hyper-V frequently adopt Xen's proven technologies. This thesis provides quantitative performance measurements of the Credit1 and Credit2 schedulers, and provides recommendations for building hypervisor schedulers.