Exploring Potential for Non-Disruptive Vertical Auto Scaling and Resource Estimation in Kubernetes

Gourav Rattihalli, Madhusudhan Govindaraju, Hui Lu, Devesh Tiwari

Abstract: Cloud platforms typically require users to provide resource requirements for applications so that resource managers can schedule containers with adequate allocations. However, the requirements for container resources often depend on numerous factors such as application input parameters, optimization flags, input files, and attributes that are specified for each run. So, it is complex for users to estimate the resource requirements for a given container accurately, leading to resource over-estimation that negatively affects overall utilization. We have designed a Resource Utilization Based Autoscaling System (RUBAS) that can dynamically adjust the allocation of containers running in a Kubernetes cluster. RUBAS improves upon the Kubernetes Vertical Pod Autoscaler (VPA) system non-disruptively by incorporating container migration. Our experiments use multiple scientific benchmarks. We analyze the allocation pattern of RUBAS with Kubernetes VPA. We compare the performance of container migration for in-place and remote node migration and we evaluate the overhead in RUBAS. Our results show that compared to Kubernetes VPA, RUBAS improves the CPU and memory utilization of the cluster by 10% and reduces the runtime by 15% with an overhead for each application ranging from 5% to 20%.