Oracle Cloud Infrastructure 2022 Architect Professional — Question 44

You work for a Travel company and your travel portal application is a collection of microservices that run on Oracle Cloud Infrastructure (OCI) Container Engine for Kubernetes (OKE).

You have noticed that Oracle has published a newer image of the Operating System (OS) for worker nodes. You want to upgrade your worker nodes to the latest version of the OS, at the same time ensuring that the application does not face any downtime.

Which procedure should you follow to upgrade without application downtime?

Answer options

• A. 1. Create a new node pool using the latest available OS image 2. Run kubectl taint nodes --all node-role.kubernetes.io/master- 3. Delete the old node pool
• B. 1. Run kubectl cordon against all the worker nodes in the old pool to stop any new application pods to get scheduled 2. Run kubectl drain --delete-local-data –force –ignore-daemonsets to evict any Pods that are running 3. Download the patches for the new OS image 4. Patch the worker nodes to the latest OS image
• C. 1. Create a new node pool using the latest available OS image 2. Run kubectl cordon against all the worker nodes in the old pool to stop any new application pods to get scheduled 3. Run kubectl drain --delete-local-data –force –ignore-daemonsets to evict any Pods that are running 4. Delete the old node pool
• D. 1. Shutdown the worker nodes 2. Create a new node pool 3. Manually schedule the pods on the newly built node pool

Correct answer: C

Explanation

The correct answer is C because it involves creating a new node pool with the latest OS image, safely draining the old nodes of any running pods, and finally deleting the old pool, which ensures a smooth transition without downtime. Option A fails to drain the nodes, which could lead to scheduling issues, while option B includes unnecessary steps like downloading patches, and option D results in downtime due to shutting down the worker nodes.