The best open source alternative to Observium is Zabbix. If that doesn't suit you, our users have ranked more than 50 alternatives to Observium and 17 is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Observium are Nagios (Freemium, Open Source), LibreNMS (Free, Open Source), Cabot (Free, Open Source) and Icinga (Freemium, Open Source).
Gather and analyze accurate statistics and performance metrics, visualize it, get notified about current and potential issues without delay, and take advantage of our time-tested professional development and support.
Munin is a networked resource monitoring tool that can help analyze resource trends and "what just happened to kill our performance?" problems. It is designed to be very plug and play. A default installation provides a lot of graphs with almost no work.
Checkmk is a monitoring tool of servers, applications, networks, cloud, containers, storage, databases, IoT and more. Checkmk is available as Raw Edition, which is 100% pure open source, and as Enterprise Edition with a lot of additional features.
Easy to use configuration web interface for nagios and neamon. openITCOCKPIT is a perfomant monitoring system with support for distributed monitoring (Satellites), REST API, nice dashboards, maps, graphs and a modular concept for easy customization.