Performance evaluation of container runtimes

The co-location of containers on the same host leads to significant performance concerns in the multi-tenant environment such as the cloud. These concerns are raised due to an attempt to maximize host resource utilization by increasing the number of containers running on the same host. The selection of a container runtime becomes critical in the case of strict performance requirements. In the scope of the study, two commonly used runtimes were evaluated: containerd (industry standard) and CRI-O (reference implementation of the CRI) on two different Open Container Initiative (OCI) runtimes: runc (default for most container runtimes) and gVisor (highly secure alternative to runc). Evaluation aspects of container runtimes include the performance of running containers, the performance of container runtime operations, and scalability. A tool called Touch- Stone was developed to address these evaluation aspects. The tool uses the CRI standard and is pluggable into any Kubernetes-compatible container runtime. Performance results demonstrate the better performance of containerd in terms of CPU usage, memory latency and scalability aspects, whereas file system operations (in particular, write operations) are performed more efficiently by CRI-O.