Twinkle: A fast resource provisioning mechanism for internet services

A key benefit of Amazon EC2-style cloud computing service is the ability to instantiate a large number of virtual machines (VMs) on the fly during flash crowd events. Most existing research focuses on the policy decision such as when and where to start a VM for an application. In this paper, we study a different problem: how can the VMs and the applications inside be brought up as quickly as possible? This problem has not been solved satisfactorily in existing cloud services. We develop a fast start technique for cloud applications by restoring previously created VM snapshots of fully initialized application. We propose a set of optimizations, including working set estimation, demand prediction, and free page avoidance, that allow an application to start running with only partially loaded memory, yet without noticeable performance penalty during its subsequent execution. We implement our system, called Twinkle, in the Xen hypervisor and employ the two-dimensional page walks supported by the latest virtualization technology. We use the RUBiS and TPC-W benchmarks to evaluate its performance under flash crowd and failure over scenarios. The results indicate that Twinkle can provision VMs and restore the QoS significantly faster than the current approaches.