In this recipe, we'll learn how to adjust the percentage thresholds for a host's or service's flap detection. This means that we can adjust how frequently a host or service has to change its state within its last 21 checks before Nagios Core concludes it's flapping and suppresses notifications until its state becomes stable again.
You should have a Nagios Core 4.0 or newer server with at least one host and one service configured already. You should also have access to a working web interface for the Nagios Core server.
You should be familiar with the way hosts and services change their state as a result of their checks and the different states corresponding to hosts and services, to understand the basics of how flap detection works. Flap detection should also already be enabled and working for the appropriate hosts and services.