In this chapter, we looked at reliable and highly available large-scale Kubernetes clusters. This is arguably the sweet spot for Kubernetes. While it is useful to be able to orchestrate a small cluster running a few containers, it is not necessary, but at scale, you must have an orchestration solution in place you can trust to scale with your system, and provide the tools and the best practices to do that.

You now have a solid understanding of the concepts of reliability and high availability in distributed systems. You delved into the best practices for running reliable and highly available Kubernetes clusters. You explored the nuances of live Kubernetes cluster upgrades and you can make wise design choices regarding levels of reliability and availability, as well as their performance and cost.

In Chapter 5, Running Kubernetes on Multiple Clouds and Cluster Federation, we will address the important topic of security in Kubernetes. We will also discuss the challenges of securing Kubernetes and the risks involved. We will learn all about namespaces, service accounts, admission control, authentication, authorization, and encryption.