Memory requests and limits in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a memory request in Kubernetes?

A memory request is the amount of memory a container is guaranteed to have. Kubernetes uses this to decide which node can run the container.

beginner

What happens if a container exceeds its memory limit in Kubernetes?

If a container uses more memory than its limit, Kubernetes may terminate the container to protect the node's stability.

intermediate

Why should you set both memory requests and limits?

Setting both helps Kubernetes schedule containers efficiently and prevents any container from using too much memory and affecting others.

intermediate

How does Kubernetes use memory requests during scheduling?

Kubernetes checks if a node has enough free memory to meet the container's memory request before placing it there.

beginner

What is the difference between memory request and memory limit?

Memory request is the minimum memory guaranteed to a container. Memory limit is the maximum memory the container can use before being terminated.

What does the memory request specify in a Kubernetes pod?

A The minimum memory guaranteed to the container

B The maximum memory the container can use

C The total memory of the node

D The CPU usage limit

Memory request is the minimum memory Kubernetes guarantees to the container.

What happens if a container exceeds its memory limit?

A The container is terminated by Kubernetes

B The container is given more memory automatically

C Nothing happens, it continues running

D The node shuts down

Kubernetes kills containers that use more memory than their limit to keep the system stable.

Why is it important to set memory requests?

A To increase network bandwidth

B To limit CPU usage

C To help Kubernetes schedule pods on nodes with enough memory

D To set disk space limits

Memory requests help Kubernetes decide where to place pods based on available memory.

If a pod has a memory request of 500Mi and a limit of 1Gi, what does this mean?

A The pod can only use 500Mi memory

B The pod is guaranteed 500Mi memory and can use up to 1Gi

C The pod must use exactly 1Gi memory

D The pod has no memory limits

The request is the guaranteed memory, and the limit is the maximum allowed.

What is the risk of not setting memory limits?

A The container will use less memory

B The container will not start

C The pod will be scheduled on the wrong node

D A container might use too much memory and crash the node

Without limits, a container can consume excessive memory and affect node stability.

Explain how memory requests and limits work together in Kubernetes to manage container memory.

Think about how Kubernetes decides where to place containers and what happens if they use too much memory.

Describe why setting memory requests and limits is important for a stable Kubernetes cluster.

Consider what happens if one container uses too much memory without limits.