Let's say we have a hostgroup of 100 hosts, all of which are being monitored for service X. Let's say this service goes down across all hosts. Rather than receiving 100 separate alerts, I'd like to receive a single alert saying that "Service X is down for the entire hostgroup" or something. Is this possible with Nagios? How to implement it? I'm looking around online but not seeing this particular situation discussed.
EDIT: note that this is not a network-facing service, this is a local check done on each host. Specifically it is a check to see whether the local SSL cert is expired or not.