Resource monitoring best practices in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Kubernetes Resource Requests and Limits

In Kubernetes, what is the primary purpose of setting resource requests and limits for containers?

A To define the exact amount of CPU and memory a container must always use during its lifetime.

B To allow containers to use unlimited resources without restrictions.

C To specify the minimum and maximum CPU and memory a container can use, helping the scheduler place pods and prevent resource overuse.

D To automatically scale the number of pods based on resource usage.

💡 Hint

Think about how Kubernetes decides where to put pods and how it avoids one pod using too much resource.

Resource requests tell Kubernetes the minimum resources a container needs, which helps the scheduler decide where to place pods. Limits set the maximum resources a container can use to prevent it from affecting other containers.

💻 Command Output

intermediate

Interpreting kubectl top pod Output

What is the output of the following command if the pod web-server-1 is using 150m CPU and 200Mi memory?

kubectl top pod web-server-1

A

NAME           CPU(cores)   MEMORY(bytes)
web-server-1   150m         200Mi

B web-server-1 150 200

C

NAME           CPU(cores)   MEMORY(bytes)
web-server-1   0.15         0.2

D Error: pod web-server-1 not found

💡 Hint

Look at the units kubectl top uses for CPU and memory.

The kubectl top pod command shows CPU in millicores (m) and memory in mebibytes (Mi) with a header row.

🔀 Workflow

advanced

Setting Up Prometheus for Kubernetes Monitoring

Which sequence of steps correctly describes setting up Prometheus to monitor Kubernetes cluster metrics?

A 1,2,3,4

B 1,3,2,4

C 2,1,3,4

D 1,2,4,3

💡 Hint

Think about deploying the operator first, then defining what to monitor, then configuring Prometheus, and finally viewing metrics.

First, deploy the Prometheus Operator. Then create ServiceMonitors to tell Prometheus what to scrape. Next, configure Prometheus to use those ServiceMonitors. Finally, access the UI to see metrics.

❓ Troubleshoot

advanced

Troubleshooting Missing Metrics in Kubernetes Monitoring

You installed Prometheus in your Kubernetes cluster, but no metrics appear for your application pods. Which is the most likely cause?

A The Prometheus Operator is running but Prometheus is not installed.

B The ServiceMonitor resource is missing or incorrectly configured for the application pods.

C The Kubernetes API server is down.

D The application pods are using too much CPU and memory.

💡 Hint

Think about how Prometheus knows which pods to monitor.

Prometheus uses ServiceMonitor resources to find and scrape metrics from pods. If these are missing or wrong, no metrics will be collected.

✅ Best Practice

expert

Best Practice for Alerting on Resource Usage in Kubernetes

What is the best practice for setting alerts on CPU and memory usage in a Kubernetes cluster to avoid false alarms?

A Set alerts only on maximum resource limits defined in pod specs.

B Set very low thresholds to catch any small increase in resource usage immediately.

C Disable alerts and rely on manual checks to avoid false alarms.

D Set alert thresholds based on historical usage patterns and include a duration to avoid firing alerts on short spikes.

💡 Hint

Think about how to balance alert sensitivity and noise.

Using historical data to set thresholds and adding a duration (e.g., alert if usage is high for 5 minutes) helps reduce false alarms caused by brief spikes.