Contacts and notification

When Do Notifications Occur?

The decision to send out notifications is made in the service check and host check logic. The calculations for whether a notification is to be sent are only triggered when processing a host or service check corresponding to that notification;

Who receives notifications?

Each host and service definition has a company option that specifies what company receives notifications for that particular host or service. Companies can contain one or more individual contacts.

When Yoopl sends out a host or service notification, it will notify each contact that is a member of any companies specified in the company option of the service definition. Yoopl realizes that a contact may be a member of more than one company, so it removes duplicate contact notifications before it does anything.

What Filters Must Be Passed In Order For Notifications To Be Sent?

Just because there is a need to send out a host or service notification doesn't mean that any contacts are going to get notified. There are several filters that potential notifications must pass before they are deemed worthy enough to be sent out. Even then, specific contacts may not be notified if their notification filters do not allow for the notification to be sent to them. Let's go into the filters that have to be passed in more detail...

Service and Host Filters:

The first filter for host or service notifications is a check to see if the host or service is in a period of scheduled downtime. If it is in a scheduled downtime, no one gets notified. If it isn't in a period of downtime, it gets passed on to the next filter. As a side note, notifications for services are suppressed if the host they're associated with is in a period of scheduled downtime.

The second filter for host or service notification is a check to see if the host or service is flapping (if you enabled flap detection). If the service or host is currently flapping, no one gets notified. Otherwise it gets passed to the next filter.

The third host or service filter that must be passed is the host- or service-specific notification options. Each service definition contains options that determine whether or not notifications can be sent out for warning states, critical states, and recoveries. Similiarly, each host definition contains options that determine whether or not notifications can be sent out when the host goes down, becomes unreachable, or recovers. If the host or service notification does not pass these options, no one gets notified. If it does pass these options, the notification gets passed to the next filter...

Note: Notifications about host or service recoveries are only sent out if a notification was sent out for the original problem. It doesn't make sense to get a recovery notification for something you never knew was a problem.

The fourth host or service filter that must be passed is the time period test. Each host and service definition has a notification_period option that specifies which time period contains valid notification times for the host or service. If the time that the notification is being made does not fall within a valid time range in the specified time period, no one gets contacted. If it falls within a valid time range, the notification gets passed to the next filter...

Note: If the time period filter is not passed, Nagios will reschedule the next notification for the host or service (if its in a non-OK state) for the next valid time present in the time period. This helps ensure that contacts are notified of problems as soon as possible when the next valid time in time period arrives.

The last set of host or service filters is conditional upon two things: (1) a notification was already sent out about a problem with the host or service at some point in the past and (2) the host or service has remained in the same non-OK state that it was when the last notification went out. If these two criteria are met, then Yoopl will check and make sure the time that has passed since the last notification went out either meets or exceeds the value specified by the notification_interval option in the host or service definition. If not enough time has passed since the last notification, no one gets contacted. If either enough time has passed since the last notification or the two criteria for this filter were not met, the notification will be sent out! Whether or not it actually is sent to individual contacts is up to another set of filters...

Contact Filters:

At this point the notification has passed the program mode filter and all host or service filters and Yoopl starts to notify all the people it should. Does this mean that each contact is going to receive the notification? No! Each contact has their own set of filters that the notification must pass before they receive it.

Note: Contact filters are specific to each contact and do not affect whether or not other contacts receive notifications.

The first filter that must be passed for each contact are the notification options. Each contact definition contains options that determine whether or not service notifications can be sent out for warning states, critical states, and recoveries. Each contact definition also contains options that determine whether or not host notifications can be sent out when the host goes down, becomes unreachable, or recovers. If the host or service notification does not pass these options, the contact will not be notified. If it does pass these options, the notification gets passed to the next filter...

Note: Notifications about host or service recoveries are only sent out if a notification was sent out for the original problem. It doesn't make sense to get a recovery notification for something you never knew was a problem...

The last filter that must be passed for each contact is the time period test. Each contact definition has a notification_period option that specifies which time period contains valid notification times for the contact. If the time that the notification is being made does not fall within a valid time range in the specified time period, the contact will not be notified. If it falls within a valid time range, the contact gets notified!

Notification Methods

You can have Yoopl notify you of problems and recoveries pretty much anyway you want: pager, cellphone, email, instant message, audio alert, electric shocker, etc. How notifications are sent depend on the notification commands that are defined in your object definition files.