Alert Log Errors: Fatal NI connect error 12170

Monitoring of the 11g database Alert log(s) may show frequent timeout related messages such as:

Alert log entry:

Fatal NI connect error 12170.

  VERSION INFORMATION:
    TNS for 64-bit Windows: Version 11.2.0.4.0 - Production
    Oracle Bequeath NT Protocol Adapter for 64-bit Windows: Version 11.2.0.4.0 - Production
    Windows NT TCP/IP NT Protocol Adapter for 64-bit Windows: Version 11.2.0.4.0 - Production
  Time: 09-JUN-2014 13:17:00
  Tracing not turned on.
  Tns error struct:
    ns main err code: 12535
   
TNS-12535: TNS:operation timed out
    ns secondary err code: 12560
    nt main err code: 505
   
TNS-00505: Operation timed out
    nt secondary err code: 60
    nt OS err code: 0
  Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=192.168.1.80)(PORT=49249))

Note : The "nt secondary err code" will be different based on the operating system.

Linux x86 or Linux x86-64: "nt secondary err code: 110"
HP-UX Server: "nt secondary err code: 238"
AIX: "nt secondary err code: 78"

These time out related messages are mostly informational in nature.  The messages indicate the specified client connection (identified by the 'Client address:' details) has experienced a time out.  The 'nt secondary err code' identifies the underlying network transport, such as (TCP/IP) timeout limits after a client has abnormally terminated the database connection.

Solution

You may choose to revert from the new Automatic Diagnostic Repository (ADR) method to prevent the Oracle Net diagnostic details from being written to the alert log(s) by setting the following Oracle Net configuration parameters:

- To revert to Oracle Net Server tracing/logging, set following parameter in the server's sqlnet.ora :

DIAG_ADR_ENABLED = OFF

Also, to back out the ADR diag for the Listener component, set following parameter in the server's listener.ora:

DIAG_ADR_ENABLED_<listenername> = OFF

Where the <listenername> would be replaced with the actual name of the configured listener(s) in the listener.ora configuration file.  For example, if the listener name is 'LISTENER', the parameter would read:

DIAG_ADR_ENABLED_LISTENER = OFF

- Reload or restart the TNS Listener for the parameter change to take effect.