Docker DCA Exam - Topic 4 Question 83 Discussion

Actual exam question for Docker's DCA exam

Question #: 83
Topic #: 4

[All DCA Questions]

You are running only Kubernetes workloads on a worker node that requires

maintenance, such as installing patches or an OS upgrade.

Which command must be run on the node to gracefully terminate all pods on

the node, while marking the node as unschedulable?

A`docker swarm leave'

B`docker node update -availability drain <node name>

C`kubectl drain <node name>'

D`kubectl cordon <node name>

Show Suggested Answer

Suggested Answer: C

The command kubectl drain <node name> is the correct one to run on the node to gracefully terminate all pods on the node, while marking the node as unschedulable. This command will safely evict all the pods from the node before you perform maintenance on the node, such as installing patches or an OS upgrade1. It will respect the PodDisruptionBudgets you have specified, if any, and allow the pod's containers to gracefully terminate1. It will also mark the node as unschedulable, so that no new pods can be scheduled on the node until it is ready1.

The other commands are not correct because:

* docker swarm leave will make the node leave the swarm cluster, but it will not affect the Kubernetes workloads on the node2.

* docker node update -availability drain <node name> will change the availability of the node to drain, which means that no new tasks can be assigned to the node, but it will not terminate the existing pods on the node3.

* kubectl cordon <node name> will mark the node as unschedulable, but it will not evict the pods on the node4.

* Safely Drain a Node | Kubernetes

* [docker swarm leave | Docker Docs]

* [docker node update | Docker Docs]

* [kubectl cordon | Kubernetes Docs]

by Sue at Mar 20, 2024, 06:07 PM

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King

3 months ago

I didn't know that! Thanks for clarifying!

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Bette

3 months ago

No doubt, `kubectl drain` is the way to go for maintenance.

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Ivan

4 months ago

Wait, are you sure? I thought `kubectl cordon` was enough.

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Renay

4 months ago

Agreed, that's the right command for draining pods!

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Dorinda

4 months ago

It's definitely `kubectl drain `.

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Carylon

4 months ago

I'm a bit confused about the difference between `drain` and `cordon`. I think `drain` is what we want here, but I should double-check that.

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Francine

5 months ago

I feel like `kubectl cordon ` just marks the node as unschedulable without terminating the pods, so it can't be the answer.

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Alva

5 months ago

I remember practicing a similar question, and I believe `kubectl drain` is the right choice to gracefully terminate pods.

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Yen

5 months ago

I think the command we need is related to Kubernetes, so it might be `kubectl drain `, but I'm not entirely sure.

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Elena

5 months ago

Okay, I've seen this type of scenario before. I believe the correct answer is `kubectl drain `. This command will safely evict all pods from the node, allowing them to be rescheduled on other nodes, and then mark the node as unschedulable.

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Delfina

5 months ago

Hmm, this seems to be testing our knowledge of Kubernetes node management. I think the key here is to find the command that can gracefully terminate all pods on the node while marking it as unschedulable. Let me think this through.

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Tomas

5 months ago

This looks like a Kubernetes-related question, so I'll need to think about the specific Kubernetes commands that would handle this scenario. I'm a bit unsure about the exact command, but I'll try to reason through it.

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Stephaine

5 months ago

I'm pretty confident the answer is `kubectl drain `. This is the standard Kubernetes command for gracefully draining a node, which will ensure all pods are terminated and rescheduled before the node is marked as unschedulable for maintenance.

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Eladia

5 months ago

Hmm, this seems like a tricky one. I'm not sure if enabling developer mode in Production is the best idea, but it might be worth a try to get the required information.

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Rosann

5 months ago

This seems straightforward. I'm pretty sure Salesforce allows you to merge up to 3 records at a time, so the answer should be "True".

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Virgie

5 months ago

This looks like a tricky accounting question involving prior period adjustments. I'll need to carefully review the information provided and think through the impact on the financial statements.

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