We have an oralce 816 client on Win NT with third party software connecting to Oracle816 DB on linux using "Merant ODBC" driver. I am getting lot of "TNS-12502: TNS:listener received no connect data from client messages" in the listener log file. I checked the tnsnames.ora on the client and it does have CONNECT_DATA specified. Does anyone know what is happening?
Thanks in Advance.
03-11-2002, 05:58 PM
The articles on Metalink point to the following:
If it's happening consistently,
incorrect entries in the TNSNAMES.ORA file(s)
specifically the service_name (sid)
If it's random .. and a listener restart fixes it temporarily, it's a bug.
Can you connect with another client app (access/golden/etc.)?
03-12-2002, 11:22 AM
It's happening consistently. I checked the tnsnames.ora file and the entries are correct.
We have an NT server with a third party software and Oracle client software 8.1.6. Third part software makes a connection to the Oracle Server dirver on linux using ODBC and it needs the connection open all the time. Also this is production environment i can't afford to bring down the NT server.
If i try to connect with another application (Excel, Acess etc..) and if i get this error "TNS-12502: TNS:listener received no connect data from client " how can i figure out which app is causing this error.
03-12-2002, 11:43 AM
To undestand further of your problem, could you answer the following questions.
1. What is your server and db versions
2. What is the client server and db version
3. What have you used in the tnsnames.ora service_name/sid
4. Is there any timeout set in the sqlnet.ora
Pl. let us know.
03-12-2002, 01:43 PM
1) What is your server and db versions?
Slackware 7.1 and Oracle 8.1.6 Server.
2) What is the client server and db version?
Windows NT4 with Oracle 8.1.5 Client.
3) What have you used in the tnsnames.ora service_name / sid ?
4) Is there any timeout set in the sqlnet.ora?
SQLNET.EXPIRE_TIME = 0
03-12-2002, 02:20 PM
in the tnsnames. set the service_name = ... instead of SID. You can know the service name from the initSID.ora file or by querying the v$parameter as sys or system. Check your ODBC connection configuration to see whether there are any timeouts defined.