The No Connection alert notifies you when its configured condition is met on Oracle instances so you can investigate and respond.
Mini DBA describes this alert as: The Oracle server cannot be contacted, either Mini DBA does not have permission to connect or the instance is down Mini DBA evaluates this alert once a minute so changes are detected quickly. Because duration is used, Mini DBA can avoid treating a single short spike as a full incident when the condition clears quickly.
This alert protects availability by warning when Mini DBA cannot reach the monitored Oracle instance or when the service state changes unexpectedly. It is often the first signal that users will see connection failures before deeper diagnostic metrics can be collected.
Enable it on every production and customer-facing Oracle instance. For development systems, keep it enabled only when the instance is expected to be continuously available or when it supports automated testing and demos.
This alert is based on a state or event rather than a numeric threshold. Tune its schedule, scope, severity, and notification route so that the response matches the importance of the instance.
Confirm the host, listener, service, firewall, DNS, and credentials first. Check whether planned maintenance is in progress, then use the relevant Oracle activity and service logs to decide whether the problem is network, engine startup, authentication, or resource exhaustion.
If the alert creates repeated noise, review whether it is enabled on the correct instances, whether maintenance windows are configured, and whether the minor and major routes match the real business impact. Keep enough history to prove the new setting before changing it broadly.