I have a host definition with the following values: normal_check_interval 5 retry_check_interval 1 notification_interval 1 Now, I receive the warning: Warning: Service ... on host ... has a notification interval less than its check interval! Notifications are only re-sent after checks are made, so the effective notification interval will be that of the check interval. The documentation about retry_interval says: This directive is used to define the number of "time units" to wait before scheduling a re-check of the service. Services are rescheduled at the retry interval when they have changed to a non-OK state. About retry_check_interval it says: Re-check the service every minute until its final/hard state is determined ... but this is noted in an example, not in the service definitions section of the manual. On the other hand, in xodtemplate.c as highlighted by someone else on this list in 2008, apparently they're equivalent. These two definitions of what retry_interval and retry_check_interval would seem to be different. One suggests it's the time between checks on a "non-OK" host. The other one suggests it's the time between checks on a non hard/final state. Is it one, the other or both? Either way, would this not mean that if I had a normal check interval of 5 minutes, and a retry check interval of 1 minute that in some cases, it would indeed be checked more often than 5 minutes and therefore be able to notify more often than the normal check interval?