PCA Monitoring, Alerting & Troubleshooting 3

Question 1

What is the purpose of the `scrape_timeout` setting in a Prometheus scrape configuration?

Accepted Answer

Maximum duration allowed for a single scrape request before it is aborted

Answer

scrape_timeout defines how long Prometheus will wait for a target's HTTP response before canceling the scrape and marking it as a failure.

Question 2

A PromQL query returns `No data` for `rate(http_requests_total[5m])`. The metric exists in Prometheus. What is the most common reason?

Accepted Answer

The selected time window is shorter than two scrape intervals

Answer

rate() requires at least two data points within the range; if the range window is shorter than two scrape intervals, there may be insufficient data.

Question 3

Which Prometheus component is responsible for discovering and maintaining the list of scrape targets?

Accepted Answer

Service discovery / relabeling pipeline

Answer

Prometheus uses service discovery mechanisms (e.g., file_sd, kubernetes_sd) combined with the relabeling pipeline to discover and configure scrape targets.

Question 4

An inhibition rule in Alertmanager has `source_match: {severity: 'critical'}` and `target_match: {severity: 'warning'}`. What happens when a critical alert fires?

Accepted Answer

Warning alerts matching the target are suppressed

Answer

Inhibition rules suppress (mute) target alerts when a matching source alert is firing, reducing redundant notifications.

Question 5

What does `increase(errors_total[1h])` calculate in PromQL?

Accepted Answer

The total increase in the counter value over the last hour

Answer

increase() calculates the total increase in a counter's value over the specified time range, accounting for resets.

(PCA) Prometheus Certified Associate Practice Test

(PCA) Prometheus Certified Associate Practice Test

PCA Monitoring, Alerting & Troubleshooting 3