What monitoring solutions do you use for Linux servers?

For monitoring Linux servers, I often use the following solutions:

• Prometheus + Grafana — for metrics collection and visualization. Prometheus is excellent for monitoring performance, service status, and OS resources.
• Zabbix — a comprehensive solution with the ability to monitor networks, servers, and applications, with a flexible trigger and alert system.
• Nagios — a classic tool for monitoring availability and service status.
• Netdata — a lightweight agent for real-time monitoring with a user-friendly web interface.
• ELK Stack (Elasticsearch, Logstash, Kibana) — for log collection and analysis, which is important for troubleshooting.

The choice depends on the tasks: if metrics and alerts are needed — Prometheus; if log collection and analysis are important — ELK; for comprehensive infrastructure monitoring — Zabbix or Nagios.