Hi,
Sometimes You can get “TNS-12518: TNS:listener could not hand off client connection ” error.
Details of error are as follows.
TNS-12518: TNS:listener could not hand off client connection
Cause: The process of handing off a client connection to another process failed.
Action: Turn on listener tracing and re-execute the operation. Verify that the listener and database
instance are properly configured for direct handoff. If problem persists, call Oracle Support.
This error is related with out of available Oracle processes.
To solve this error, you should increase the PROCESSES parameter as follows.
SQL> show parameter processes NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ aq_tm_processes integer 1 db_writer_processes integer 1 gcs_server_processes integer 0 global_txn_processes integer 1 job_queue_processes integer 1000 log_archive_max_processes integer 4 processes integer 1500 SQL> SQL> SQL> alter system set processes=2000 scope=spfile; System altered. SQL>
Restart database after this operation.
Or you should check ‘max user processes’ etc. with ‘ulimit -a‘ command, and if it is insufficient, then increase it.
For windows environment.
set logging_listener_name=on in the listener.ora and reload the listener.
Or restart all Oracle services, it will be fine.
Do you want to learn more details about RMAN, then read the following articles.
https://ittutorial.org/rman-backup-restore-and-recovery-tutorials-for-beginners-in-the-oracle-database/