Virtualization can provide significant benefits in data centers, such as dynamic resource configuration, live virtual machine migration. Services are deployed in virtual machines (VMs) and resource utilization can be greatly improved. In this paper, we present VScheduler, a system that dynamically adjusts processor resource configuration of virtual machines, including the amount of virtual resource and a new mapping of virtual machines and physical nodes. VScheduler implements a two-level resource configuration scheme -- local resource configuration (LRC) for an individual virtual machine and global resource configuration (GRC) for a whole cluster or data center. GRC especially takes variation tendency of workloads into account when remapping virtual machines to physical nodes. We implement our techniques in Xen and conduct a detailed evaluation using RUBiS and dbench. The experimental results show that VScheduler not only satisfies resource demands of services, but also reduces the number of virtual machines migration, which can provide a stable VM distribution on physical nodes in data centers.
['Hai Jin', 'Li Deng', 'Song Wu', 'Xuanhua Shi']
Dynamic Processor Resource Configuration in Virtualized Environments