Which component in Zabbix is responsible for generating alerts based on criteria set by the user?

Triggers are the core component in Zabbix responsible for generating alerts based on user-defined criteria. They evaluate the data collected from items at specific intervals or upon changes to identify situations that require attention, such as performance issues or outages.

When a trigger evaluates to true, it indicates a problem condition, which consequently generates an event. This event can then be acted upon, typically leading to notifications or other actions as configured by the user. The flexibility of triggers allows users to define specific thresholds or conditions that, when met, prompt alerts, making them essential for proactive monitoring.

While other components like items and actions play important roles in the overall monitoring framework, it is the trigger that specifically focuses on the logic to determine when an alert should be raised. Items are the monitored metrics, actions dictate how to respond to events generated from triggers, and events represent occurrences of problems but do not create alerts by themselves.