Odd issue w/ DNS service / host up alert


#1

So we had Monday off for MLK day, and while we were off one of our main servers decided to reboot. (Odd, but whatever.) Anyway, the server comes back online, but the ‘DNS server’ service does not. (Odd as well, but whatever again)…

My problem is this - while nagios knew that the ‘DNS server’ service was down on said server, the mail it was sending out was simply “host up” alerts, not DNS down alerts. So starting saturday around midnight, I have emails about every 3 - 10 mins from nagios stating:

Notification type: PROBLEM
Host: tflserver
State: UP

then ip and ping ok info (which are fine). No mention at all of DNS.

Upon arriving here this morning and starting the ‘DNS server’ service by hand, i got the following:

Notification type: RECOVERY
Host: tflserver
State: UP

then ip and ping ok info (which are fine). Still no mention at all of DNS.

Seems strange that nagios would not just page with a warning about DNS being down, no?
Edited ]


#2

Nagios sends alerts on “STATE CHANGES” only. That explains why you got the recovery alert when you restarted the DNS service. If you did not get the alert when the service went down, that is due to the host being down at that time. Why you then got many alerts about the host being up, I don’t know. Are you using a beta nagios? Once the server was back up, and the DNS service check failed, you should have been notified. Unless of course, you have your settings to NOT notify upon “u” undetermined. Which is what I suspect.