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Troubleshooting Guide TNS-12519 TNS-12516 ORA-12519 ORA-12516 (Doc ID 552765.1)

Last updated on JANUARY 16, 2025

Applies to:

Oracle Net Services - Version 9.2.0.8 and later
Oracle Database - Standard Edition - Version 19.16.0.0.0 and later
Gen 2 Exadata Cloud at Customer - Version All Versions and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Information in this document applies to any platform.

Purpose

Helps to understand these listener log errors.  The circumstances under which they're thrown
and to aid in resolution.

TNS - 12519  TNS: no appropriate service handler found
TNS - 12516 TNS : listener could not find instance with matching protocol stack

You are facing TNS - 12519 / TNS - 12516 in the client application or Listener log.

Troubleshooting Steps

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In this Document
Purpose
Troubleshooting Steps
 Background Of The Error:
 Known Issues :
 Diagnostic Information :
References

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