Hansel: diagnosing faults in openStack

With majority of the world's data and computation handled by cloud-based systems, cloud management stacks such as Apache's CloudStack, VMware's vSphere and OpenStack have become an increasingly important component in cloud software. However, like every other complex distributed system, these cloud stacks are susceptible to faults, whose root cause is often hard to diagnose. We present HANSEL, a system that leverages non-intrusive network monitoring to expedite root cause analysis of such faults manifesting in OpenStack operations. HANSEL is fast and accurate, and precise even under conditions of stress.