Requests and Limits in Kubernetes. What are they and why are they needed?

In Kubernetes, Requests and Limits are parameters that specify the minimum and maximum resources (CPU, memory) allocated to a container.

• Requests — this is the guaranteed minimum of resources that the container will receive. The Kubernetes scheduler uses these values to determine on which node to place the pod.
• Limits — this is the maximum resource limit that the container can use. If the container exceeds this limit, for example, in memory, it may be restarted.

Why is this needed:

• To ensure cluster stability so that one container does not "consume" all resources.
• To enable more efficient load distribution among nodes.
• To prevent situations where containers compete for resources and affect each other.

Configuration example:

resources:
  requests:
    memory: "256Mi"
    cpu: "500m"
  limits:
    memory: "512Mi"
    cpu: "1"