IT Tutorial

ORA-12535: TNS operation timed out

Sometimes You can get “ORA-12535: TNS:operation timed out ” error.


ORA-12535: TNS operation timed out

Details of error are as follows.

ORA-12535: 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.

[oracle@msdbadm01 admin]$ tnsping MSDB

TNS Ping Utility for Linux: Version - Production on 06-MAY-2020 13:02:57

Copyright (c) 1997, 2013, Oracle. All rights reserved.

Used parameter files:

Used TNSNAMES adapter to resolve the alias
TNS-12535: TNS:operation timed out
[oracle@msdbadm01 admin]$





This ORA-12535 error is related with firewall or listener timeout.


If firewall is open, then disable it as follows.

service iptables stop
chkconfig iptables off

service ip6tables stop
chkconfig ip6tables off

You can disable firewall in Redhat with below script.

systemctl stop firewalld
systemctl disable firewalld



TNS operation timed out

Or Check your IP Adress, Port if they are incorrect, you can get this error. To solve this error, fix IP adress and port.



TNS-12535 and ORA-03135: connection lost contact error are related with the Network traffic and High loaded database operations.

To solve this error, add the following parameter to the SQLNET.ORA file ( under $ORACLE_HOME/network/admin/ ).




then restart the Listener as follows.

$ srvctl stop listener
$ srvctl start listener



$ lsnrctl stop listener

$ lsnrctl start listener


Or Check database server if it is up or not.


Do you want to learn Oracle Database for Beginners, then Click and read the following articles.

Oracle Database Tutorials for Beginners ( Junior Oracle DBA )

 1,680 views last month,  3 views today

Exit mobile version