Nagios Support Forum

I have the following settings configured for an alert:

Check Interval = 5m
Loopback Period = 60m
Warning = 0
Critical = 0

The following events occurred that met the query criteria of the alert:

Event #1 occurred @ 2017-05-16T15:27:02.000
Event #2 occurred @ 2017-05-16T15:27:02.000
Event #3 occurred @ 2017-05-16T15:46:46.000
Event #4 occurred @ 2017-05-16T15:46:46.000
Event #5 occurred @ 2017-05-16T15:46:46.000

From the audit logs, type=ALERT:

2017-05-16T15:29:14.020-04:00 ALERT Alert Name TEST returned CRITICAL: 2 matching entries found |logs=2;0;0
2017-05-16T15:34:29.049-04:00 ALERT Alert Name TEST returned CRITICAL: 2 matching entries found |logs=2;0;0
2017-05-16T15:39:44.065-04:00 ALERT Alert Name TEST returned CRITICAL: 2 matching entries found |logs=2;0;0
2017-05-16T15:44:49.037-04:00 ALERT Alert Name TEST returned CRITICAL: 2 matching entries found |logs=2;0;0
2017-05-16T15:49:54.133-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T15:55:04.888-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:00:04.113-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:05:09.166-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:10:14.407-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:15:29.380-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:20:44.503-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:25:49.476-04:00 ALERT Alert Name TEST returned CRITICAL: 5 matching entries found |logs=5;0;0
2017-05-16T16:31:08.524-04:00 ALERT Alert Name TEST returned CRITICAL: 3 matching entries found |logs=3;0;0
2017-05-16T16:36:24.356-04:00 ALERT Alert Name TEST returned CRITICAL: 3 matching entries found |logs=3;0;0
2017-05-16T16:41:29.427-04:00 ALERT Alert Name TEST returned CRITICAL: 3 matching entries found |logs=3;0;0
2017-05-16T16:46:34.491-04:00 ALERT Alert Name TEST returned CRITICAL: 3 matching entries found |logs=3;0;0

I am looking for a way to check the logs every X minutes (or seconds) and look for new events and fire the alert if found.
What is the best practice for doing this without missing any alerts and without having duplicate alerts occur for the same events? In the case above, I would expect 2 alerts, not 16 alerts.

The best way to setup the alert it to set the Check Interval and the Loopback Period to the same time so when the check does run, it will only look in the time period since the last run and that should stop the duplicated alerts.

If the Loop back time is larger than the check interval, it will run the check until the errors drop below the threshold level and on your example that would take 60 minutes to do.