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ORA-12535: TNS: operation timed out tips

Oracle Error Tips by Stephanie F.


Question:  I am getting the ORA-21535 error when attempting to connect to Oracle:


             ORA-12535: TNS: operation timed out


How do I fix this ORA-13595 error?

Answer: The oerr utility note this on the ORA-12535 error:

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.

To diagnose a ORA-12535 error, follow these steps to ensure connectivity to Oracle:


1 - Check your client-side sqlnet log files for more details

2 - Try a direct connection from your client using tnsping:

tnsping <servicename>

3 - Run a statspack or AWR report and look at the top-5 timed events. If "SQL*Net" waits are there, you may need to tune your network (SDU, TDU).

4 - Adjust the timeout threshold.   The sqlnet.ora file entry sqlnet.recv_timeout is used to limit the time, specified in seconds, for a database server to wait for client data after a connection is established. When this parameter is set, a client must send some data within the specified time interval.




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