⏱️ Estimated Reading Time: 14 minutes
Oracle Listener Health Check
It’s 2 AM. Your phone lights up with alerts. Applications are down, dashboards are red,
and every connection attempt fails with TNS-12541: TNS:no listener.
The database is up — but the business is still dead.
In real production environments, a failed Oracle Listener can block thousands of users, cause SLA breaches, and trigger revenue loss within minutes. We’ve seen P99 login latency jump from milliseconds to total outages.
This guide shows how to implement a production-grade Oracle Listener health check using scripts, monitoring logic, and automation — before the listener becomes your single point of failure.