70 Use case "Service state"

So assume some kind (not real) Upstream-NTP-Server providing a DCF77-Clock for all you systems in the network.

If this service fails, over the the time all the chrony- or windows-time-services will start to complain that they cannot contact their timeserver.

Then you could define a rule like this:

In this case the server fails the plugin will set downtimes on all those depend services, and prevent all the alarms.

Instead of pointing to a single DCF77-Services you could also define a BI-aggregation which includes the UP/DOWN-State of the NTP-Host itself and of course also the backup-node with the backup DCF77-clock, so only when both hosts and clocks fail the downtimes are set.

Using this method opens a wide range of possibility to set on downtimes based on complex states.