Date Added: Nov 2012
Consolidating Virtual Machines (VMs) in data centers is desirable as it reduces hardware and power costs. However the performances of VMs on shared physical servers are not isolated from each other as they contend for the same server resources. This contention degrades the performance of delay sensitive applications and can increase response times by three orders of magnitude at high contention levels. In order to achieve Service Level Agreements (SLAs) under VM consolidation, resources must be allocated by considering the performance effects of contention. The authors therefore present VARACO, a contention-aware VM management system to achieve Quality-of-Service (QoS) targets for multi-tier web applications.