Nagios
Nagios Core is the industry-standard open-source monitoring engine that revolutionized IT infrastructure monitoring. For over 25 years, Nagios has been the trusted choice for monitoring servers, networks, applications, and services, serving over one million users worldwide. Its plugin-based architecture and extensive community ecosystem make it one of the most versatile monitoring platforms available.
Key Features
- Plugin architecture — Thousands of community-contributed plugins extend Nagios to monitor virtually any service, device, or application
- Alerting and notification — Flexible notification system with escalation paths, contact groups, and multiple delivery methods including email, SMS, and custom scripts
- Event handling — Automatic response to service state changes with configurable event handlers for self-healing infrastructure
- Trending and capacity planning — Performance data logging enables long-term trend analysis and capacity forecasting through graphing add-ons
- Distributed monitoring — Nagios Core supports distributed and redundant monitoring configurations for large-scale deployments
- Web interface — The built-in CGI-based web interface provides real-time status, history, and reporting views accessible from any browser
- NRPE and NCPA agents — Remote monitoring agents enable checking internal metrics on Windows and Linux systems behind firewalls
Why Use Nagios?
Nagios Core remains the most battle-tested monitoring engine available, with a quarter-century of development and a massive community ecosystem. Its simplicity and reliability make it ideal for organizations that want full control over their monitoring configuration without complex setup requirements. The extensive plugin library means you can monitor almost anything with pre-built checks.
Use Cases
- Network infrastructure monitoring for routers, switches, and firewalls
- Server health monitoring including CPU, memory, disk, and process checks
- Application and service availability monitoring with custom plugin development
- Compliance and SLA reporting with historical performance data
Platform
Linux · Unix · Windows
Licence
GNU General Public License v2.0