When do SQLNET.ORA changes take effect ?
When we change some values in the SQLNET.ORA file, are the changes are immediately applied or do we need to restart any services?
Solution
For client installations, changes to the SQLNET.ORA file take immediate effect for new outgoing connections, you do not need to restart any service.
For server side installations, the SQLNET.ORA file is being read only upon a server process is being started, or by the listener service when is being (re)started or reloaded. That means that, as a premise, only new incoming connections may see these changes.
For the listener service, if you made any changes also affecting the listener (e.g.
tcp.validnode_checking configuration), then you must restart or reload the listener (e.g. with “lsnrctl reload“) for the changes to take effect.
For the DB instance, since there are two DB server models (dedicated mode and shared server / MTS mode), which employ different methods to start server processes, we have two cases:
- if the DB works in dedicated mode (or clients use only dedicated connections), then new connections will see the SQLNET.ORA changes without requiring any services to be restarted
- if the DB works in shared server / MTS mode (or clients use only shared mode connections), then new connections will see the SQLNET.ORA changes only after the instance is being restarted
In second case described above you may work around restarting the whole instance by attempting to restart only the DB dispatcher processes — you will need to shutdown (all) running dispatcher processes with “ALTER SYSTEM SHUTDOWN [IMMEDIATE] Dxxxx” (see Note 1005259.6 for details). Please
take into account that this is not a recommended action.
References
Note 1005259.6 – Shared Server (MTS) Diagnostics
