This might be a very basic question, but I am not very familiar with the exact features of Nagios versus Munin versus other monitoring tools.
Let's say we have a process that needs to run daily for some very important infrastructure reasons. We've had cases where the process did not run or was otherwise down for a number of days before anyone noticed.
I'd like to set up a system that will enable me to easily know when the daily run did not take place for some reason.
I can set up this process to send an email on every successful run (or every failed run), but I do not trust that the people receiving this email would notice an absence of an "I'm OK" message.
What I am envisioning is some type of "tripwire" service which this V.I.P. (very-important-process) can send a status message to each time it runs, whether successfully or not; and if the "tripwire" service has not received any word from the VIP within a configurable amount of time, it can then send an alert to someone.
(The difference between what I envision and the first approach I outlined is a service that sends a message only in abnormal conditions, rather than a service that sends messages each day that the status is normal/OK).
Can Nagios be set up to send an alert like this, if it has not heard from a certain service/device/process in N days? Is there another tool out there which does have this feature?