IaaS Reactive Autoscaling Performance Challenges

The main feature of a cloud application is its scalability. Major IaaS cloud services providers (CSP) employ autoscaling on the level of virtual machines (VM). Other virtualization solutions (e.g. containers, pods) can also scale. An application scales in response to change in observed metrics, e.g. in CPU utilization. Occasionally, cloud applications exhibit the inability to meet the Quality of Service (QoS) requirements during the scaling caused by the reactivity of autoscaling solutions. This paper provides the results of the autoscaling performance evaluation for two-layered virtualization (VMs and Kubernetes pods) conducted in the public clouds of AWS, Microsoft and Google using the approach and the Autoscaling Performance Measurement Tool developed by the authors.