Fast Hypervisor Recovery Without Reboot
Diyu Zhou, Yuval Tamir · 2018
System recovery latency is decreased by using microreboot to reboot only the failed component instead of the entire system. For large, complex components, such as hypervisors, even the latency of microreboot is unacceptably high in important deployment scenarios. We investigate an alternative component-level recovery mechanism, which we call microreset, that can achieve dramatically lower recovery latency for some such components. Instead of component reboot, microreset quickly resets the component to a quiescent state that is highly likely to be valid and where the component is ready to handle new or retried interactions with the rest of the system. We present a recovery mechanism for the Xen hypervisor, called NiLiHype, based on microreset. We show that, compared to microreboot-based hypervisor recovery, NiLiHype achieves nearly the same recovery success rate but with a recovery latency that is shorter by a factor of over 30.