Yoopl has the ability to distinguish between "normal" services and "volatile" services. The is_volatile option in each service definition allows you to specify whether a specific service is volatile or not. For most people, the majority of all monitored services will be non-volatile (i.e. "normal"). However, volatile services can be very useful when used properly...
Volatile services are useful for monitoring...
Volatile services differ from "normal" services in three important ways. Each time they are checked when they are in a hard non-OK state, and the check returns a non-OK state (i.e. no state change has occurred)...
These events normally only occur for services when they are in a non-OK state and a hard state change has just occurred. In other words, they only happen the first time that a service goes into a non-OK state. If future checks of the service result in the same non-OK state, no hard state change occurs and none of the events mentioned take place again.
Tip Tip: If you are only interested in logging, consider using stalking options instead.
If you combine the features of volatile services and passive service checks, you can do some very useful things. Examples of this include handling SNMP traps, security alerts, etc.