What defines a 'threshold alert' in PagerDuty?

A threshold alert in PagerDuty is specifically related to performance metrics crossing predetermined thresholds. This type of alert is designed to monitor metrics such as CPU usage, memory consumption, or response times that are critical to the functionality and performance of services. When these metrics exceed or fall below the defined thresholds, the threshold alert is triggered, signaling that there may be an underlying issue that needs attention.

This mechanism is crucial in proactive incident management, as it allows teams to react to potential problems before they escalate into significant incidents. By monitoring these metrics and establishing clear thresholds, organizations can ensure that they are alerted in a timely manner, enabling swift action to mitigate any impact on services.

The other options do not accurately describe the nature of a threshold alert. For instance, alerts based on user feedback or those triggered upon resolution of incidents serve different purposes, focusing more on human input or incident lifecycle management rather than the continuous performance monitoring associated with threshold alerts.