Q8S: Emulation of Heterogeneous Kubernetes Clusters Using QEMU

Kubernetes has emerged as the industry standard for container orchestration in cloud environments. Its scheduler dynamically places container instances across cluster nodes based on predefined rules and algorithms. Various efforts exist to extend and improve upon the Kubernetes scheduler, however, as the majority of Kubernetes clusters operate on homogeneous hardware, most scheduling algorithms are also only developed for homogeneous systems. Heterogeneous infrastructures require specialized tuning to optimize workload assignment for which researchers and developers working on scheduling systems require access to heterogeneous hardware for development and testing, which may not be available. While simulations like CloudSim or K8sSim can provide insights, as simulations the level of detail they can offer to validate new schedulers is limited. To address this, we introduce Q8S, a tool for emulating heterogeneous Kubernetes clusters on OpenStack using QEMU. Q8S emulations provide a higher level of detail than simulations and can be used to train machine learning scheduling algorithms. By providing a more realistic environment, Q8S enables researchers and developers to test and refine their scheduling algorithms, ultimately leading to more efficient and effective heterogeneous cluster management. We release our implementation of Q8S as open source such that it can be further customized.