Understanding distributed monitoring

There are many situations in which you may want to have more than one Nagios instance monitoring your IT infrastructure. One of them can be because of firewall rules that force checks to be made within local networks. Another reason could be the need to load balance all checks across machines due to latency or the number of checks. Others may need to monitor machines in different physical locations from separate machines to check what is wrong within the local infrastructure, even if the links to the central servers are temporarily down.

Regardless of the reason you may want or need to have the execution of checks split across multiple computers. This type of setup might sound complicated and hard to configure, but it is not as hard as it seems. All that's necessary is to set up multiple Nagios instances along with the NRDP agents or daemons.

There are subtle differences in how various instances need to be configured. Usually, there are one or more...