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Connections to Database Fail Reporting ORA-12547: TNS lost connection (Doc ID 1289174.1)

Last updated on JANUARY 20, 2025

Applies to:

Oracle Net Services - Version 9.2.0.8 and later
Oracle Database - Enterprise Edition - Version 11.2.0.4 and later
Gen 2 Exadata Cloud at Customer - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Exadata Cloud Service - Version N/A and later
Information in this document applies to any platform.

Symptoms

Connections to the database, intermittently start to fail, reporting the error code ORA-12547: TNS lost connection.Upon checking the server, Netstat command shows many threads with a state of LISTENING  for local and Foreign address 0.0.0.0


Sockets are never released and a restart of the database free the resources.
ORA-12547 is a sympton of lack of sockets on the system
Setting SQLNET.EXPIRE_TIME does not help

Cause

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In this Document
Symptoms
Cause
Solution


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