Certified Kubernetes Application Developer (CKAD) Study Guide, 2nd Edition

Chapter 18. Resource Requirements, Limits, and Quotas

Workload executed in Pods will consume a certain amount of resources (e.g., CPU and memory). You should define resource requirements for those applications. On a container level, you can define a minimum amount of resources needed to run the application, as well as the maximum amount of resources the application is allowed to consume. Application developers should determine the right-sizing with load tests or at runtime by monitoring the resource consumption.

Note

Kubernetes measures CPU resources in millicores and memory resources in bytes. That’s why you might see resources defined as 600m or 100Mi. For a deep dive on those resource units, it’s worth cross-referencing the section “Resource units in Kubernetes” in the official documentation.

Kubernetes  administrators  can  put  measures  in  place  to  enforce  the  use  of  available resource capacity. We’ll discuss two Kubernetes primitives in this realm, the ResourceQuota and the LimitRange. The ResourceQuota defines aggregate resource constraints on a namespace level. A LimitRange is a policy that constrains or defaults the resource allocations for a single object of a specific type (such as for a Pod or a PersistentVolumeClaim).

Coverage of Curriculum Objectives

This chapter addresses the following curriculum objective:

• Understand and define resource requirements, limits, and quotas

Working with Resource Requirements

It’s recommended practice that you specify ...