Performance impacts when moving from a VM-based solution to a container-based solution

Abstract: Container-based solutions are increasing in popularity and thus more companies grav- itate towards them. However, with systems growing larger and more complex there is a general need to introduce container orchestration to manage the increase of containers. While adopting these technologies, Ericsson has noticed some increase in CPU usage when switching from a VM-based solution to a container-based solution with Kubernetes. Thus this paper is focusing on identifying the factors that may impact CPU usage in this kind of scenario. To do this, a literature review was performed to identify potential factors and an experiment was conducted on these factors to determine their impact on CPU usage. The results show that factors such as number of Pods in a request chain, the message size between Pods, and where Pods are located in a Kubernetes cluster, may impact the CPU usage of a container-based system using Kubernetes. The number of Pods in the request chain and message size between Pods had the largest impact on CPU usage, and thus a conclusion could be drawn that network I/O is the prime factor one should look into when making sure that a container-based solution performs as good as possible.