LinuxTechi - https://www.linuxtechi.com/install-configure-icinga2-centos-7-rhel-7/
Icinga 2 is an open source monitoring tool that is used for checking the availability of IT resources (Network, servers etc) & report the outage in case a resource is down. It also generates performance data for reporting purposes as well.
Icinga 2 has multi-threaded design & can run thousands of checks each seconds without affecting the CPU. We can also setup Icinga 2 with high availability clusters with a distributed setup for large/complex environments.
In this tutorial, we will learn to install Icinga 2 on CentOS/ RHEL 7 systems. Below are my lab setup details for Icinga 2