Cloud Monitoring
Google Cloud's metrics, dashboards, and alerting service. An alert policy requires a Notification Channel explicitly attached to actually notify someone when it fires - without one, the policy still evaluates and logs its own firing history, but nobody is ever told, a common and easy-to-miss misconfiguration.
Frequently Asked Questions
Why can an alert policy in Cloud Monitoring 'fire' without anyone actually being notified?
An alert policy's condition-evaluation logic and its notification mechanism are separate concerns by design — the policy itself only defines when a metric crosses a threshold, and it logs that firing event and shows it as active in the console regardless of whether anyone is told. A Notification Channel (email, SMS, PagerDuty, Slack webhook) has to be explicitly attached to the policy for an actual alert to go out; an unattached policy will happily track its own incident history forever while paging nobody.
What's the most common way this notification gap goes unnoticed?
Alert policies are frequently created via Terraform or gcloud scripts where the notification channel ID is a separate resource reference that's easy to omit or get wrong, and there's no error at creation time if it's missing — the policy deploys successfully either way. Teams typically only discover the gap during an actual incident, when they check the console after an outage and find the alert had been firing for hours with a full incident timeline but zero notifications sent, because the channel attachment step was silently skipped.