collectd

A daemon that collects system performance statistics periodically, and provides tons of plugins to store and analyze these values

     

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Monit

An open source utility for managing and monitoring processes, programs, files, directories and filesystems

     

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Nagios Core

Nagios Core network monitoring software is a powerful, enterprise-class host, server, application, monitoring and alerting tool

     

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Rex

A agent-less server orchestration tool built on Perl

     

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Sentry

Automate error tracking to find and fix issues before your users even experience a crash. Sentry is open-source, real-time, and loved by 100,000 developers around the world.

     

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Supervisord Monitor

Supervisord Monitor is multi server monitoring tool for supervisor - watch, start and stop all your supervisord instances and servvices from one place.

     

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Zabbix

An open source, enterprise-class monitoring framework

     

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