The on-call team wants a page sent to their paging tool whenever the ratio of 5xx responses to total requests stays above 2% for five minutes. Which Cloud Monitoring feature provides this?
Show answer and explanation
Answer: D
An alerting policy evaluates a condition over a metric or a ratio across a time window, such as above 2 percent for five minutes. When the condition is met, it opens an incident and sends notifications through channels such as PagerDuty, email or Slack. Uptime checks test whether an endpoint responds, dashboards only display data, and a log sink exports log entries without evaluating any threshold, so none of those would page the team on this ratio.
Why the other options are wrong
- A. An uptime check tests reachability of an endpoint from several locations. It does not compute a 5xx ratio over all requests, so it would miss partial errors.
- B. A dashboard displays metrics and threshold lines for people to look at. It sends no notification, so the team would only learn of the problem by watching the screen.
- C. A log sink forwards entries to Pub/Sub for other processing. It does not evaluate a threshold over time, so it cannot decide when to page someone.