KOSMOS: Vertical and Horizontal Resource Autoscaling for Kubernetes

Cloud applications are increasingly executed onto lightweight containers that can be efficiently managed to cope with highly varying and unpredictable workloads. Kubernetes, the most popular container orchestrator, provides means to automatically scale containerized applications to keep their response time under control. Kubernetes provisions resources using two main components: i) Horizontal Pod Autoscaler (HPA), which controls the amount of containers running for an application, and ii) Vertical Pod Autoscaler (VPA), which oversees the resource allocation of existing containers. These two components have several limitations: they must control different metrics, they use simple threshold-based rules, and the reconfiguration of existing containers requires stopping and restarting them.