Module 08 · Virtualization and containers · Drill

Virtualization and containers drill

Scenario prompts that check whether virtualization and containers is usable under pressure. Answer out loud, then compare.

4 prompts25 minNew

0 of 4 graded

Prompt 1
You are building a platform that runs arbitrary customer-submitted code (like an online judge or a serverless product) on shared hosts. Choose the isolation boundary for each job, justify it against containers alone, and list the resource controls you would apply.
Say your answer out loud first. Thirty seconds is enough.
Prompt 2
After moving a JVM service from VMs to Kubernetes with limits of 2 CPUs and 3 GB, it suffers long GC pauses, CPU throttling, and occasional OOM kills, although it ran fine on a 2-vCPU, 4 GB VM. Explain each symptom in terms of namespaces and cgroups, and fix the configuration.
Say your answer out loud first. Thirty seconds is enough.
Prompt 3
Cluster autoscaling adds nodes during traffic spikes, but new pods take 90 seconds to become ready, 70 of them pulling a 1.8 GB image. Redesign the image and the rollout so pods are ready in under 15 seconds, and explain what each change saves.
Say your answer out loud first. Thirty seconds is enough.
Prompt 4
Explain to a junior engineer, with concrete mechanisms, the difference between a VM and a container in what is isolated, what is shared, how fast each starts, and what 'running as root' means in each. Then say when you would choose each for a new internal service, a database, and a CI runner executing pull requests from external contributors.
Say your answer out loud first. Thirty seconds is enough.