ORA-12606: TNS: Application timeout occurred


Sometimes You can get “ORA-12606: TNS: Application timeout occurred ” error.


Details of error are as follows.

ORA-12606: TNS: Application timeout occurred
Cause: A network session did not reach an application-defined stage within the allowed time interval.
Action: This is an error which does not normally appear at the high level.
The action to take is application specific, and is detailed in the higher level error description.
Error TNS-12535 when connecting to Oracle database via dispatchers (shared servers).

The dispatcher trace shows following error message -

NS Primary Error: TNS-12535: TNS:operation timed out
NS Secondary Error: TNS-12606: TNS: Application timeout occurred
kmduicxd: 0EEE01DC, kmduiflg: 1, circuit: 4D08C930
(circuit) dispatcher process id = (85917028, 1)
parent process id = (64, 1)
serial # = 44
connection context = 0EEE01DC
user session = (00000000), flag = (100c0), queue = (9)
current buffer = (0), status = (4, 0)
Client Address = (ADDRESS=(PROTOCOL=tcp)(HOST=<IP address>)(PORT=<port>))




This error is related with the the default setting for INBOUND_CONNECT_TIMEOUT in listener.ora is 60 seconds, to solve this error increase this value more than 60 like 360, and reload listener.
Or second case related with this error is as follows.
The SHARED_SERVER parameter is set to an inadequate value and should be raised.   A connection via shared server will fail if there are no free shared servers available to honor the request.

The 12535 error in the dispatcher trace indicates that the connection was timed out in the dispatchers queue.

To solve this error, Increase value for following database parameters –


These parameters are modifiable using ALTER SYSTEM.


SQL> alter system set shared_server=30 scope=both sid='*';    
SQL> alter system set max_shared_server=300 scope=both sid='*';

Do you want to learn more details about RMAN, then read the following articles.



About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

Leave a Reply

Your email address will not be published. Required fields are marked *