Memory requests should be set (GITA-PRO-006)

The memory of a computer is one of its limited resources. On clustered Linux systems, complex processes in the form of containers are constantly competing for such resource. Furthermore, given that these processes may perform tasks which require distinct amounts of resources, there exists a necessity of ensuring such amount will be available.

This is what memory requests are used for. By specifying how much memory a container may need, the process scheduler can ensure the container only starts if that exact quantity is available. In a similar manner, the scheduler also uses the request value to select a node where the container will execute, comparing it with the available memory of each node.

Such value can be specified directly through Kubernetes manifests. To do this, add a resources field to the manifest as the example below:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
    - name: redis
      image: redis:latest
      resources:
        requests:
          memory: 50M

For more information, visit the Kubernetes documentation.