ORA-12516 TNS:listener could not find available handler with matching protocol stack

Sometimes You can get ” ORA-12516 TNS:listener could not find available handler with matching protocol stack  ” error.

 

ORA-12516 TNS:listener could not find available handler

Details of error are as follows.

ORA-12516 TNS:listener could not find available handler with matching protocol stack

Cause: None of the known and available service handlers for the given SERVICE_NAME support the client's

protocol stack: transport, session, and presentation protocols.




Action: Check to make sure that the service handlers (e.g. dispatchers) for the given SERVICE_NAME are registered

with the listener, are accepting connections, and that they are properly configured to support the desired protocols.

This error is related with out of available Oracle processes.

 

Oracle Processes Parameter

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 can create a static listener and start it as follows.

Add the following listener descriptions to the listener.ora file under $ORACLE_HOME/network/admin.

 

Check your Hostname, Port, DB Name and fill them correctly.

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.63.34)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)

SID_LIST_LISTENER = 
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = MSDB)
(ORACLE_HOME = /u01/app/db_home_18c )
(SID_NAME = MSDB1 )
)
)

[oracle@msdbadm01 ~]$ lsnrctl start LISTENER

 

 

 

Do you want to learn more details about RMAN, then Click this Link and read the articles.