Fatal ni connect error 12547

TNS-12547 : TNS Lost Contact using ODBC / OLE DB on Windows 2000 Laptop

We are experiencing application failures on Windows 2000 laptops running Oracle9i versions 9.2.0.3 and later.
The symptom is intermittent ODBC / OLE DB failures resulting from: TNS-12547: TNS:lost contact
The LISTENER.ORA has (QUEUESIZE=100) specified.
The INIT<SID>.ORA file has open_cursors=1000 and processes=250.
Any suggestions? 

I have a similar problem here on a 2000k box running 9.2.0.1. Getting "TNS-12547: TNS:lost contact" final error message in listener log and from them no response from listener anymore. No restart nothing possible.
This happens only once in a while.
Beside sqlplus there is only one process accessing the DB via ODBC.
I have not increased the trace level yet since I don't know when it is happening again. 

I've got the same problem. I'm trying to access the O9i 9.2. Either through TOAD or ODBC, I get an error from TNSLSNR:
VERSION INFORMATION:
     TNS for 32-bit Windows: Version 9.2.0.1.0 - Production
     Windows NT TCP/IP NT Protocol Adapter for 32-bit Windows: Version 9.2.0.1.0 - Production
Time: 14-JUL-2006 09:57:41
Tracing not turned on.
Tns error struct:
nr err code: 0
ns main err code: 12547
TNS-12547: TNS:contacto perdido
ns secondary err code: 12560
nt main err code: 517
TNS-00517: Contacto perdido
nt secondary err code: 54
nt OS err code: 0
Any ideas?

ORA-12547 TNS : lost contact

Hi,
I am running oracle apps 11.5.10.2 on Windows server 2003 (as guest OS on Microsoft virutal pc 2007).
My host OS is Windows 7 Professional.
I am trying to connect to the apps database using SQL Plus 11g client from Windows 7.
It throws an error ORA 12547 TNS lost contact.
I am able to access the front end on host but cannot connect to backend.
Can anyone help me what's wrong with my settings/what should i change?
Thanks
Rk 

While you may think you post intuitively obvious to a casual observer, I am not clear on even how many different systems are being discussed.
post tail end from listener.log from the server which is throw the error.
has this ever worked? if so, what changed?
does any firewall exist between you & system that fails? 

Here is the log file content
Fatal NI connect error 12547, connecting to:
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ORACLE.apps.com)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=VIS)(INSTANCE_NAME=VIS)(CID=(PROGRAM=C:Virtual_Serverproduct11.1.0client_2BINsqlplus.exe)(HOST=PLUTO)(USER=Rk))))
VERSION INFORMATION:
     TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
     Windows NT TCP/IP NT Protocol Adapter for 32-bit Windows: Version 11.1.0.6.0 - Production
Time: 21-AUG-2009 17:06:43
Tracing not turned on.
Tns error struct:
ns main err code: 12547
TNS-12547: TNS:lost contact
ns secondary err code: 12560
nt main err code: 517
TNS-00517: Lost contact
nt secondary err code: 54
nt OS err code: 0
This is the first time I am trying to connect, I have disabled all the firewalls and still facing the same problem.
Thanks
Rk 

VERSION INFORMATION:
TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
Windows NT TCP/IP NT Protocol Adapter for 32-bit Windows: Version 11.1.0.6.0 - Production
Time: 21-AUG-2009 17:06:43
Tracing not turned on.
Tns error struct:
ns main err code: 12547
TNS-12547: TNS:lost contact
ns secondary err code: 12560
nt main err code: 517
TNS-00517: Lost contact
nt secondary err code: 54
nt OS err code: 0
=====================
All this means the request went from the client & got to the listener.
Some sort of OS (Windoze) error occurred.
Any clues within OS log files? 

I am not sure where to check for Windows error/log files. Is there a specific log file to look into? or any other troubleshooting method you can think of?
Thanks
Rk 

I have not been on Windows since Windows97.
Talk to your SA or post to a Windoze forum.
Are there any clues in alert_<SID>.log file? 

Hi,
This error is indicative of a problem at the OS level. You might set sql net tracing to get more information. You will need to check the syslog created in windows to know what is happening at the OS level.
REgards
Chandra 

Hi Chandra,
I have set sql net tracing, and when i try to log in i get ORA-12570 TNS Packet reader failure.
The system log says The Computer Browser service entered the stopped state.
Any idea what this is?
Thanks
Rk 

open command window & issue following command
dir /w $ORACLE_HOMEDBS
post command & results back here
Is the DB instance up & online now?
Edited by: sb92075 on Aug 22, 2009 4:41 PM 

When I issued the command it says The system cannot find the file specified
Yes, the DB instance is up and online
Thanks
Rk 

open command window & issue following command
dir /w $ORACLE_HOME
post command & results back here

TNS-12535: TNS:operation timed out & TNS-00505: Operation timed out problem

Hi all,
I am getting below error frequently on different ports + (55733 55758 56110 59365 62950 63573 63790 63992) + and connecting automatically after some period.
Fatal NI connect error 12170.
VERSION INFORMATION:
TNS for Linux: Version 11.2.0.2.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.2.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.2.0 - Production
Time: 18-MAR-2011 09:16:27
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: 110
nt OS err code: 0
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain.com)(+ PORT=55733 +))
Please help me why this happening frequently and conencting automatically in this regard,
Thanks, 

Try to do tnsping localhost.localdomain.com and see if connection is possible and also i am not sure whether symbol +* around port in your client address is right syntax or not.
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain.com)(+ PORT=55733 +)) 

Hi Sunny,
Yeah connection is there but getting disconnect frequently and reconnecting again....
I was trying to make that string as italic so put the '+' symbol, and doesn't have + symbol in original file.
Please help
Edited by: user7280060 on Mar 24, 2011 1:55 AM 

On MOS (My Oracle support):
Troubleshooting Guide TNS-12535 or ORA-12535 or ORA-12170 Errors [ID 12535.1] 

Hi,
1) check SQLNET.LOG to find other errors.
2) Turn on tracing.
3) This may be a result of network or system delays; or this may indicate that a malicious client is trying to cause a Denial of Service attack on the server. so just check sqlnet.log file. 

What would I look for in the log to indicate that it was a DOS attack? 

942193 wrote:
What would I look for in the log to indicate that it was a DOS attack?The DB Server should be behind FireWall system & not susceptible to DOS attack

About lisnter

Yesterday I have seen a lot of error in alert.log,But I haven't slove the problem.
Fatal NI connect error 12170.
VERSION INFORMATION:
TNS for Linux: Version 11.2.0.1.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.1.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.1.0 - Production
Time: 11-JAN-2012 11:58:18
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: 110
nt OS err code: 0
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=60.247.119.26)(PORT=60581))
Wed Jan 11 11:59:57 2012 

TNS:operation timed out
Cause:     The requested operation could not be completed within the time out period.
Action:     Look at the documentation on the secondary errors for possible remedy. See SQLNET.LOG to find secondary error if not provided explicitly. Turn on tracing to gather more information. 

Try a direct connetion from your client using tnsping:
tnsping <servicename> 

Hi CKPT,
I haven't find the secondary error in SQLNET.LOG,it seems all OK.Anyother method? thanks. 

Hi Sailaja,
The client is a remote machine,not mine,and I can't do anything in it.But my /etc/resolve.conf is null. 

Belt wrote:
Yesterday I have seen a lot of error in alert.log,But I haven't slove the problem.Before solving a problem, you first need to comprehensively and correctly identify WHAT the problem to solve is.
The following errors are from which server process exactly? Dedicated server process? Dispatcher process? Listener process?
Fatal NI connect error 12170.
TNS-12535: TNS:operation timed out
ns secondary err code: 12560
nt main err code: 505Knowing the server process that threw this error, isolates the problem in the server-side s/w stack.
The client details given:
Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=60.247.119.26)(PORT=60581))This means that client IP 60.247.119.26 used private port 60581 (on its side) to communicate with the local server process (using port 1521).
Things to check are:
- is the server in the same subnet as the client?
- if not, how robust and correct is the routing table?
- does the route go via one or more firewalls?
- what does the tcp stats of the server show ito errors?
- are there any IPv4 errors in the kernel log for that time?
- is the server using full-duplex to the local switch?
- how many hops does a trace route show?
- are any one of these hops to the client obviously slow?
etc.
If the problem occurs regularly, then enable SQL*Net debug tracing on the server-side for client connections. That will contain more detail for isolating and identifying the problem. 

Thanks,I will try it.

Oracle Listener abruptly disconnects

Hi,
I am using Oracle 8.0.6, Win Srv 2003 (32-bit). The server has 12GB RAM, but utilizes less bcoz of 32 bit.
I am facing a strange situation now a days. Sometimes the users cannot connect to the database if the no of sessions reach 420+. We have set the limit for max sessions around 555. When i faced this situation, i got the below error file on my pc.
Fatal OSN connect error 12547, connecting to:
(DESCRIPTION=(CONNECT_DATA=(SID=ORCL)(CID=(PROGRAM=TOAD.exe)(HOST=ATIQ)(USER=Ateeq)))(ADDRESS_LIST=(ADDRESS=
(PROTOCOL=ipc)(KEY=GNP.WORLD))(ADDRESS=(COMMUNITY=tcp.world)(PROTOCOL=TCP)(Host=134.50.X.X)(Port=1521))(ADDRESS=
(COMMUNITY=tcp.world)(PROTOCOL=TCP)(Host=134.50.X.X)(Port=1526))))
VERSION INFORMATION:
TNS for 32-bit Windows: Version 2.3.2.1.0 - Production
Windows NT TCP/IP NT Protocol Adapter for 32-bit Windows: Version 2.3.2.1.3 - Production
Time: 09-APR-12 11:05:46
Tracing not turned on.
Tns error struct:
nr err code: 12206
TNS-12206: TNS:received a TNS error during navigation
ns main err code: 12547
TNS-12547: TNS:lost contact
ns secondary err code: 12560
nt main err code: 517
TNS-00517: Lost contact
nt secondary err code: 54
nt OS err code: 0
The listener.log shows the following error:
TNS-12500: TNS:listener failed to start a dedicated server process
TNS-12560: TNS:protocol adapter error
TNS-00530: Protocol adapter error
I have to restart the listener to solve this problem. Please suggest what causes the error. 

I suggest you to read following doc in MOS its really helpful
Troubleshooting Guide for ORA-12500: TNS:listener failed to start a dedicated server process [ID 555448.1]
If this error is INTERMITTEN, then there are following solutions
a) Increase the processes parameter
b) Reduce the size of large_pool_size, this might work in some case.
c) Delete listener.log if its very large.
Hope this help 

The sessions doesnt reach near the max limit.
I am deleting listener log every month. 

There is a maximum number of threads per Windows process.
If I recall correctly it's 512.
You either need to switch to a real operating system, or configure multithreaded server.
Also you need to upgrade this paleolithic version of Oracle to something supported in the current century.
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Sybrand Bakker
Senior Oracle DBA