Kubernetes: What pod uses most CPU on a node? - kubernetes

Question

Is there any way to list all PODs that are using the most CPU on the node using kubectl command. I could not see this in the official documentation.

Answer 1

You can get by using
kubectl top pods # This will give you which pod is using how much CPU and Memory
kubectl top nodes # This will give you which node is using how much CPU and Memory
Make sure metric server has deployed on the cluster.

Answer 2

To know which pod scheduled on a specific node has most CPU requests you can describe that node and check the Non-terminated Pods section.
kubectl describe node masternode
Non-terminated Pods: (8 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits AGE
--------- ---- ------------ ---------- --------------- ------------- ---
kube-system calico-kube-controllers-76d4774d89-vmsnf 0 (0%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system calico-node-t4qzr 250m (12%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system coredns-66bff467f8-v9mn5 100m (5%) 0 (0%) 70Mi (1%) 170Mi (4%) 30d
kube-system etcd-ip-10-0-0-38 0 (0%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system kube-apiserver-ip-10-0-0-38 250m (12%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system kube-controller-manager-ip-10-0-0-38 200m (10%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system kube-proxy-nf7jp 0 (0%) 0 (0%) 0 (0%) 0 (0%) 30d
kube-system kube-scheduler-ip-10-0-0-38 100m (5%) 0 (0%) 0 (0%) 0 (0%) 30d
If the cluster have metrics server deployed then below commands are useful to know pod and node CPU utilization
kubectl top podname
kubectl top nodename

Answer 3

For nodes that have many pods across multiple namespaces I use an alias in .bash_profile. Outputs the cpu and memory for all pods on given node.
kntp () {
for p in `kubectl get pods --all-namespaces --field-selector spec.nodeName=$1` | grep -v "Completed" | tail -n +2 | awk '{print $2}'`; do
kubectl top pod --all-namespaces --field-selector metadata.name=$p | tail -n +2
done
}
Run it like
source ~/.bash_profile
kntp my-node-name-here

Answer 4

You can use:
kubectl top pods --all-namespaces --sort-by=cpu
To find the CPU and memory usage of all the pods among all available namespaces.
The CPU (cores) is the CPU usage:
338m means 338 millicpu. 1000m is equal to 1 CPU, hence 338m means 33.8% of 1 CPU.