How to Implement Nagios Topography to avoid over-alerting. Also how can we improve nagios performance to get avoided from fake alerts.
You can use host and service dependency definition in your configs.
For example:
define servicedependency {
host_name host1
service_description NRPE Status
dependent_service_description CPU Load
inherits_parent 1
execution_failure_criteria u,c,p,
notification_failure_criteria u,c,p,
dependency_period 24x7
}
dependent_service_description CPU Load
These are the service that are dependent on the NRPE Status service
notification_failure_criteria u,c,p
When NRPE Status service is in the UNKNOWN (u), CRITICAL (c) or PENDING (p) state, the dependent service CPU Load will NOT have notifications sent out (if they were already in a state for notifications to be sent)
execution_failure_criteria u,c,p
When NRPE Status service is in the UNKNOWN (u), CRITICAL (c) or PENDING (p) state, the dependent service CPU Load will NOT be executed