January
21st,
2020
Here are a few handy commands to check and see how much cpu and memory your Openshift cluster is using.
Node Utilisation
$ oc adm top node will show how much memory and cpu your nodes are using.
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| [root@host ~]# oc adm top node | |
| NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% | |
| master0 408m 11% 3377Mi 21% | |
| master1 546m 15% 2772Mi 17% | |
| master2 448m 12% 3325Mi 21% | |
| worker0 238m 6% 2151Mi 13% | |
| worker1 257m 7% 2188Mi 14% | |
| worker2 128m 3% 1367Mi 11% |
$ oc describe node/$nodeName will give details about the allocated resources:
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| [root@host ~]# oc describe node/master0 | |
| Name: master0 | |
| Roles: master | |
| Labels: beta.kubernetes.io/arch=amd64 | |
| beta.kubernetes.io/os=linux | |
| #REDACTED | |
| Allocated resources: | |
| (Total limits may be over 100 percent, i.e., overcommitted.) | |
| Resource Requests Limits | |
| -------- -------- ------ | |
| cpu 1520m (43%) 0 (0%) | |
| memory 4389Mi (28%) 512Mi (3%) | |
| ephemeral-storage 0 (0%) 0 (0%) | |
| Events: <none> |
This can be shortened to the following command:
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| #NodeName, cpu requests, cpu limits, memory requests, memory limits | |
| [root@host ~]# oc get node --no-headers | while read node stat role age ver; do echo -ne "$node\t"; oc describe node $node | egrep '^ (cpu|memory)' | sed -r 's/\(|\)//g' | while read lbl x p1 y p2; do echo -n \ $p1 $p2 ; done; echo ""; done | |
| master0 43% 0% 28% 3% | |
| master1 40% 0% 23% 3% | |
| master2 44% 0% 27% 3% | |
| worker0 33% 8% 17% 3% | |
| worker1 35% 8% 19% 3% | |
| worker2 22% 2% 15% 4% |
Pod Utilisation
$ oc adm top pod will give an idea of which pods are the most hungry. Omnomnom.
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| [root@host ~]# oc adm top pod --all-namespaces | |
| NAMESPACE NAME CPU(cores) MEMORY(bytes) | |
| openshift-apiserver apiserver-729wn 4m 111Mi | |
| openshift-apiserver apiserver-bjgqh 7m 113Mi | |
| openshift-apiserver apiserver-cv94b 5m 115Mi | |
| openshift-apiserver-operator openshift-apiserver-operator-7bcd69678-9r8fl 3m 31Mi | |
| openshift-authentication oauth-openshift-7469964dbb-7h6w2 1m 20Mi | |
| openshift-authentication oauth-openshift-7469964dbb-r65bj 1m 20Mi | |
| openshift-authentication-operator authentication-operator-55f4b64744-9csk9 4m 48Mi | |
| openshift-cloud-credential-operator cloud-credential-operator-75f696fdf7-fwggh 1m 60Mi | |
| openshift-cluster-machine-approver machine-approver-854544ff4d-h9wbm 0m 13Mi | |
| openshift-cluster-node-tuning-operator cluster-node-tuning-operator-56485dcbb4-5gg7p 0m 28Mi | |
| #REDACTED |
We can also break this down to a node level by extracting the information from oc describe node with the following:
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| #NodeName, CPU Requests CPU Limits Memory Requests Memory Limits AGE (from oc describe node) | |
| [root@host ~]# oc get node --no-headers | while read node stat role age ver; do oc describe node $node | egrep '.+(%.+){3}' | sed -r 's/\(|\)//g' | while read line; do echo $node $line; done; echo ""; done | column -t | |
| master0 openshift-apiserver-operator openshift-apiserver-operator-7bcd69678-9r8fl 10m 0% 0 0% 50Mi 0% 0 0% 45h | |
| master0 openshift-apiserver apiserver-bjgqh 150m 4% 0 0% 200Mi 1% 0 0% 45h | |
| master0 openshift-cloud-credential-operator cloud-credential-operator-75f696fdf7-fwggh 10m 0% 0 0% 150Mi 0% 0 0% 45h | |
| master0 openshift-cluster-machine-approver machine-approver-854544ff4d-h9wbm 10m 0% 0 0% 50Mi 0% 0 0% 45h | |
| master0 openshift-cluster-node-tuning-operator tuned-pxp9v 10m 0% 0 0% 50Mi 0% 0 0% 45h | |
| master0 openshift-cluster-version cluster-version-operator-cb6bf8766-2cdsh 20m 0% 0 0% 50Mi 0% 0 0% 45h | |
| master0 openshift-controller-manager-operator openshift-controller-manager-operator-b6856d4ff-nvc9c 10m 0% 0 0% 50Mi 0% 0 0% 45h | |
| # REDACTED |
Hope that was helpful :o)
