## <a id="volatile-services"></a> Volatile Services

By default all services remain in a non-volatile state. When a problem
occurs, the `SOFT` state applies and once `max_check_attempts` attribute
is reached with the check counter, a `HARD` state transition happens.
Notifications are only triggered by `HARD` state changes and are then
re-sent defined by the `notification_interval` attribute.

It may be reasonable to have a volatile service which stays in a `HARD`
state type if the service stays in a `NOT-OK` state. That way each
service recheck will automatically trigger a notification unless the
service is acknowledged or in a scheduled downtime.