Scaling Non-elastic Applications Using Virtual Machines

Hardware virtualization is a cost effective mean to reduce the number of physical machines (PMs) required to handle computational tasks. Virtualization also guarantees high levels of isolation (performance and security wise) between virtual machines running on the same physical hardware. Besides enabling consolidation of workloads, virtual machine (VM) technology also offers an application independent way of shifting workloads between physical machines. Live migration, i.e., shifting workloads without explicitly stopping the virtual machine, is particularly attractive because of the minimal impact on virtual machine and hence service availability. We explore the use of live migration to scale non-elastic (i.e., static runtime configuration) applications dynamically. Virtual machines thus provide an application agnostic way to dynamic scalability, and open new venues for minimizing the physical resource usage in a data center. We will show that virtualization technology in connection with the live migration capabilities of modern hyper visors can be used to scale non-elastic application in a generic way. Some problems still present in current virtualization techniques with respect to live migration will also be highlighted.