How to Find Memory and CPU Metrics for a Kubernetes Pod

Monitoring memory or CPU usage in a Pod is crucial to do any Kind of work in Kubernetes and make our application are reliables.

The most basic command that we can use to do some monitoring is kubectl top But before, you need to check ...

Metrics Server

Before you can fetch memory metrics, ensure that the Metrics Server is installed and running in your cluster. The kubectl top command depends on it to retrieve live CPU and memory statistics.

kubectl get deployment metrics-server -n kube-system

If it’s not installed, you can add it using:

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

Note: The Metrics Server can take a couple of minutes to install, be patient.

How to use Kubectl top

To check the memory (and CPU) usage of a specific pod, use the following command:

kubectl top pod <pod-name> --namespace=<namespace>

Replace:

<pod-name> with the name of your pod

<namespace> with the namespace the pod is running in

Example:

kubectl top pod nginx-deployment-5c689d4b4b-lv9xl --namespace=default

Output:

NAME                                 CPU(cores)   MEMORY(bytes)
nginx-deployment-5c689d4b4b-lv9xl   5m           22Mi

This output shows the live memory usage in MiB and CPU usage in millicores.

To List memory usage for all pods in a namespace:

kubectl top pod --namespace=<namespace>

To List all pod metrics across all namespaces:

kubectl top pod --all-namespaces

To Sort by memory usage (Linux only):

kubectl top pod --all-namespaces | sort -k4 -h

Get node-level memory metrics:

kubectl top node

Troubleshooting

If kubectl top returns an error like:

Error from server (NotFound): the server could not find the requested resource (get services http:heapster:)

It typically means:

That rhe Metrics Server isn’t installed or isn’t working correctly.

The cluster version is incompatible with your Metrics Server version.

Check the logs of the Metrics Server:

kubectl logs -n kube-system deploy/metrics-server