Service Dependency kick-off

[durgaraoyv]

Hi

When Multiple Services (Ex: Service1 ; Service2) are made Master Service, on UNKNOWN/ CRITICAL states, for other services (Ex: Service3, Service4, Service5) within a host,
When does Service Dependency kicks-off ?

Both Service1 AND Service2 should become UNKNOWN/CRITICAL, then Service Dependency kicks-off
Only Service1 should become UNKNOWN/CRITICAL, then Service Dependency kicks-off
Only Service2 should become UNKNOWN/CRITICAL, then Service Dependency kicks-off

Thank you.

[benjaminsmith]

Hi,

That's a good question, and here's the official doc on it.

How Service Dependencies Are Tested
Before Nagios executes a service check or sends notifications out for a service, it will check to see if the service has any dependencies. If it doesn't have any dependencies, the check is executed or the notification is sent out as it normally would be. If the service does have one or more dependencies, Nagios Core will check each dependency entry as follows:

1. Nagios gets the current status* of the service that is being depended upon.
2. Nagios Core compares the current status of the service that is being depended upon against either the execution or notification failure options in the dependency definition (whichever one is relevant at the time).
3. If the current status of the service that is being depended upon matches one of the failure options, the dependency is said to have failed and Nagios Core will break out of the dependency check loop.
4. If the current state of the service that is being depended upon does not match any of the failure options for the dependency entry, the dependency is said to have passed and Nagios Core will go on and check the next dependency entry.
This cycle continues until either all dependencies for the service have been checked or until one dependency check fails.

See: https://assets.nagios.com/downloads/nag ... ncies.html

So, it only has to match one of the failure options in Service1 or Service2.

Let us know if you have more questions.
--Benjamin