what is the impact of uprading kubelet if we leave the pods on the worker nodes

0 votes
what is the impact of uprading kubelet if we leave the pods on the worker nodes - will it break running pods? why?
Jul 18, 2019 in Kubernetes by Namik
• 1,230 points
3,231 views

1 answer to this question.

0 votes
  • Restarting kubelet, which has to happen for an upgrade will cause all the Pods on the node to stop and be started again. 

  • It’s generally better to drain a node because that way Pods can be gracefully migrated, and things like Disruption Budgets can be honored. 

  • The problem is that `kubectl` keeps up with the state of all running pods, so when it goes away the containers don’t necessarily die, but as soon as it comes back up, they are all killed so `kubectl` can create a clean slate. 

  • As kubelet communicates with the apiserver, so if something happens in between of upgrade process, rescheduling of pods may take place and health checks may fail in between the process. 

  • During the restart, the kubelet will stop querying the API, so it won’t start/stop containers, and Heapster won’t be able to fetch system metrics from cAdvisor. 

  • Just make sure it’s not down for too long or the node will be removed from the cluster!

answered Jul 18, 2019 by Sirajul
• 59,230 points

Related Questions In Kubernetes

0 votes
1 answer
–1 vote
1 answer

order to apply kubernetes-dashboard ? before I join the worker nodes or after the join of the worker node ?

Not really. There are a few things ...READ MORE

answered Mar 18, 2019 in Kubernetes by Vardhan
• 13,190 points
919 views
0 votes
2 answers

How do I update all my pods if the image is changed but the tag is the same?

since K8s 1.15 kubectl rollout restart do the ...READ MORE

answered Jul 24, 2020 in Kubernetes by Mathieu V
6,762 views
0 votes
1 answer
+1 vote
1 answer
0 votes
3 answers

Error while joining cluster with node

Hi Kalgi after following above steps it ...READ MORE

answered Jan 17, 2019 in Others by anonymous
14,523 views
+4 votes
1 answer

Installing Web UI (Dashboard):kubernetes-dashboard on main Ubuntu 16.04.6 LTS (Xenial Xerus) server

Follow these steps: $ kubeadm reset $ kubeadm init ...READ MORE

answered Apr 12, 2019 in Kubernetes by Kalgi
• 52,360 points

reshown Apr 12, 2019 by Kalgi 5,975 views
0 votes
1 answer

What all components is the Master server in Kubernetes made up of?

Kubernetes is a combination of multiple parts ...READ MORE

answered Jul 11, 2019 in Kubernetes by Sirajul
• 59,230 points
1,112 views
0 votes
1 answer

How to determine what is the status of a deployment ?

You could use kubectl get deployment <deployment>.  If ...READ MORE

answered Jul 12, 2019 in Kubernetes by Sirajul
• 59,230 points
460 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP