Configuring Listener
Oracle 12c Installation
About listener
Listener is a process which is used for connecting oracle client and database server. Some important points on LISTENER.
STEPS TO CONFIGURE LISTENER
Type netca in linux, which will popup a GUI screen.
Choose listener configuration.
Choose Add to create a new listener.
Give the name for the LISTENER
Cick the Next button, which by defaut chooses TCP Protocol
Choose the port 1521 which is default port, else you can customise the port number.(Make sure the port is not used by other applications, to check , use linux command [ netstat -tunlp ])
Choose Yes, if you need to configure additional listeners.
Click Next ,Listener configuration is done.
Click Finish.
The above configuration will create a listener.ora file in $ORACLE_HOME/network/admin, with listener entry.
[oracle@linux admin]$ cat listener.ora # listener.ora Network Configuration File: /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora # Generated by Oracle configuration tools. LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = linux.localdomain)(PORT = 1521)) (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)) ) )
Oracle LISTENER Configuration using NETCA(Network Configuration Assistant)
We see no database is resigtered with the listener. So starting up the database.[oracle@linux admin]$ lsnrctl status LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 27-MAY-2020 00:43:02 Copyright (c) 1991, 2016, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=linux.localdomain)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production Start Date 27-MAY-2020 00:42:27 Uptime 0 days 0 hr. 0 min. 35 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora Listener Log File /home/oracle/app/oracle/diag/tnslsnr/linux/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=linux.localdomain)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) The listener supports no services The command completed successfully [oracle@linux admin]$ lsnrctl status LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 27-MAY-2020 00:43:19 Copyright (c) 1991, 2016, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=linux.localdomain)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production Start Date 27-MAY-2020 00:42:27 Uptime 0 days 0 hr. 0 min. 52 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora Listener Log File /home/oracle/app/oracle/diag/tnslsnr/linux/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=linux.localdomain)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) The listener supports no services The command completed successfully
After starting the database, the database is registered with the listener.[oracle@linux admin]$ sqlplus SQL*Plus: Release 12.2.0.1.0 Production on Wed May 27 00:43:21 2020 Copyright (c) 1982, 2016, Oracle. All rights reserved. Enter user-name: / as sysdba Connected to an idle instance. SQL> !ps -ef|grep pmon oracle 21498 21467 0 00:43 pts/0 00:00:00 /bin/bash -c ps -ef|grep pmon oracle 21500 21498 0 00:43 pts/0 00:00:00 grep pmon SQL> startup ORACLE instance started. Total System Global Area 838860800 bytes Fixed Size 8626240 bytes Variable Size 335548352 bytes Database Buffers 490733568 bytes Redo Buffers 3952640 bytes Database mounted. Database opened. SQL> Disconnected from Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
Now, configuring the tnsnames.ora to connect database, which will create tnsnames.ora files under $ORACLE_HOME/network/admin/[oracle@linux admin]$ lsnrctl status LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 27-MAY-2020 00:43:59 Copyright (c) 1991, 2016, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=linux.localdomain)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production Start Date 27-MAY-2020 00:42:27 Uptime 0 days 0 hr. 1 min. 32 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora Listener Log File /home/oracle/app/oracle/diag/tnslsnr/linux/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=linux.localdomain)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) Services Summary... Service "demo" has 1 instance(s). Instance "demo", status READY, has 1 handler(s) for this service... The command completed successfully [oracle@linux admin]$ netca Oracle Net Services Configuration: Default local naming configuration complete. Created net service name: demo Oracle Net Services configuration successful. The exit code is 0
[oracle@linux admin]$ cat /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/tnsnames.ora # tnsnames.ora Network Configuration File: /home/oracle/app/oracle/product/12.2.0/dbhome_1/network/admin/tnsnames.ora # Generated by Oracle configuration tools. DEMO = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = demo) ) ) [oracle@linux admin]$ sqlplus scott/tiger@demo SQL*Plus: Release 12.2.0.1.0 Production on Wed May 27 00:46:16 2020 Copyright (c) 1982, 2016, Oracle. All rights reserved. Last Successful login time: Wed May 27 2020 00:45:17 +05:30 Connected to: Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production SQL> select global_name from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- DEMO SQL> Disconnected from Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production [oracle@linux admin]$