Prometheus

Prometheus is an open-source metrics and monitoring solution often used in cloud-native environments. It scrapes time-series data from exporters, then triggers alerts when rules are violated. Alertmanager (companion tool) handles routing and silencing of these alerts to on-call teams. While not a full ITSM tool, Prometheus suits DevOps teams needing a free approach for metrics-based incident detection, real-time alerting, and integration with chat or paging systems for incident resolution.