Tns-12502:tns:listener received no connect_data from client

Checking the listening logs of one of our Oracle databases found a number of TNS-12502 error messages. As shown below

Tns-12502:tns:listener received no connect_data from client

09-dec-2014 15:47:06 * (Connect_data= (Service_name=epps) (Cid= (Program=d:\tasks\fgis2mes\ceg\gmt_auto.exe) (HOST= CEGWEB1) (user=cegadmin)) * (Address= (PROTOCOL=TCP) (host=192.163.21.14) (port=2312)) * Establish * Epps * 0

$ oerr TNS 12502

12502, 00000, "Tns:listener received no connect_data from client"

*cause:no Connect_data was passed to the listener.

*action:check the service name resolved from TNSNames. ORA has

The Connect_data component of the CONNECT descriptor.

This error generally occurs because the client Tnsnames.ora does not contain connect_data cause, but as shown above, the client Tnsnames.ora already contains connect_data data, most of the time normal, But occasionally in the Listener.log found the error message, and there is no regularity, and finally in Oracle's TNS-12502 error cause and resolution this article learned that the client through the Telnet database server 1521 Port test connectivity, The following error will also occur. As shown below:

Telnet 192.168.20.11 1521

View/u01/app/oracle/product/10.2.0/db_1/network/log/listener.log as shown below and you will see the TNS-12525 error message.

12-dec-2014 20:40:33 * <unknown Connect data> * (address= (PROTOCOL=TCP) (host=192.168.125.113) (PORT=52651)) * Establish * <unknown sid> * 12525

Tns-12525:tns:listener have not received client's request in time allowed

Tns-12535:tns:operation timed out

Tns-12606:tns:application Timeout occurred

12-dec-2014 20:40:37 * service_update * Epps * 0

But this is different from the error message found in the Listening log: Tns-12502:tns:listener received no connect_data from client, I've counted the timing of TNS-12502 errors and it's hard to find any rules. It is strange that this error does not affect the user's use. So far, I have not figured out why this error occurred. Make a record for a while and leave it to study and solve later!

Resources:

Http://www.eygle.com/archives/2006/08/oracle_tns_12502.html

Tns-12502:tns:listener received no connect_data from client