Manage
the Listener Using the Listener Control Utility 
Before You Begin
This 15mins tutorial introduces you to the listener control utility which enables you to administer the listener.
Select the Oracle Database release:
Background
Oracle Net Listener is a process that runs on the database server computer. It receives incoming client connection requests and manages the request traffic. Listener configuration information is stored in the listener.ora file and includes one or more listening protocol addresses, information about supported services, and parameters that control its run-time behavior. The listener is configured during the creation of the database. You can use the Listener Control Utility to administer the listener after it is configured.
What Do You Need?
- Install Oracle Database 18c19c
- Create a Database
View
the Listener Configuration
Use the Listener Control utility STATUS command
to display basic status information about a listener, including
a summary of listener configuration settings, listening protocol
addresses, and a summary of services registered with the
listener. To execute the STATUS command, perform
the following steps:
- Open a terminal window and execute the oraenv
command to set the environment variables.
$ . oraenv ORACLE_SID = [oracle] ? orcl The Oracle base has been set to /scratch/u01/app/oracle - Execute the lsnrctl status
command.
$lsnrctl statusLSNRCTL for Linux: Version 18.0.0.0.0 - Production on 05-MAR-2019 01:52:41 Copyright (c) 1991, 2018, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP) (HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 18.0.0.0.0 - Production Start Date 03-MAR-2019 23:30:55 Uptime 1 days 2 hr. 21 min. 45 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/18.0.0 /dbhome_1/network /admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr /slc12ftw/listener /alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp) (HOST=host01.us.oracle.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host01.example.com) (PORT=5500))(Security=(my_wallet_directory=/scratch/u01/app /oracle/admin/orcl/xdb_wallet)) (Presentation=HTTP)(Session=RAW)) Services Summary... Service "orcl.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclXDB.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... The command completed successfullyLSNRCTL for Linux: Version 19.0.0.0.0 - Production on 15-JUL-2019 01:09:40 Copyright (c) 1991, 2019, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production Start Date 10-JUL-2019 01:32:04 Uptime 4 days 23 hr. 37 min. 36 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/19.0.0/dbhome_1/network/admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host01.example.com)(PORT=5500))(Security=(my_wallet_directory=/scratch/u01/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW)) Services Summary... Service "86b637b62fdf7a65e053f706e80a27ca.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "8d50ba5e384412fbe053193ec40a5c2c.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orcl.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclXDB.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclpdb.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... The command completed successfully
Note: If the Pluggable Database(PDB) is configured, you will see a service for each PDB.
Start
the Listener
The Oracle listener is set to start automatically whenever the
host is restarted. If a problem occurs in your system or you
have manually stopped the listener, you can restart it by using
the lsnrctl start command.
- For the purposes of this tutorial, stop the listener by
executing the lsnrctl stop
command.
$ lsnrctl stopLSNRCTL for Linux: Version 18.0.0.0.0 - Production on 07-MAR-2019 07:13:34 Copyright (c) 1991, 2018, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com) (PORT=1521))) The command completed successfully LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 15-JUL-2019 02:58:16 Copyright (c) 1991, 2019, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com)(PORT=1521))) The command completed successfully
- Now that the listener is stopped, log in to SQL*Plus as the
SYSTEM user using the orcl
service name to determine whether you can still connect to the
database.
$ sqlplus system@orcl SQL*Plus: Release 18.0.0.0.0 Production on Mon Mar 07 07:14:15 2019 Copyright (c) 1982, 2018, Oracle. All rights reserved. Enter password: Enter password here ERROR: ORA-12541: TNS:no listener Enter user-name:SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jul 15 03:00:11 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle. All rights reserved. Enter password: ERROR: ORA-12541: TNS:no listener
Exit the prompt by pressing Ctrl + C followed by Enter.
- Restart the listener by using the lsnrctl
start command.
$ lsnrctl startLSNRCTL for Linux: Version 18.0.0.0.0 - Production on 07-MAR-2019 01:10:17 Copyright (c) 1991, 2018, Oracle. All rights reserved. Starting /scratch/u01/app/oracle/product/18.0.0/dbhome_1/bin/tnslsnr: please wait... TNSLSNR for Linux: Version 18.0.0.0.0 - Production System parameter file is /scratch/u01/app/oracle/product/18.0.0/dbhome_1/network/admin/listener.ora Log messages written to /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 18.0.0.0.0 - Production Start Date 07-MAR-2019 01:10:17 Uptime 0 days 0 hr. 0 min. 0 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/18.0.0/dbhome_1/network/admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) The listener supports no services The command completed successfullyLSNRCTL for Linux: Version 19.0.0.0.0 - Production on 15-JUL-2019 03:01:00 Copyright (c) 1991, 2019, Oracle. All rights reserved. Starting /scratch/u01/app/oracle/product/19.0.0/dbhome_1/bin/tnslsnr: please wait... TNSLSNR for Linux: Version 19.0.0.0.0 - Production System parameter file is /scratch/u01/app/oracle/product/19.0.0/dbhome_1/network/admin/listener.ora Log messages written to /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production Start Date 15-JUL-2019 03:01:01 Uptime 0 days 0 hr. 0 min. 0 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/19.0.0/dbhome_1/network/admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) The listener supports no services The command completed successfully
- Check the listener status by executing the lsnrctl
status command.
$ lsnrctl statusLSNRCTL for Linux: Version 18.0.0.0.0 - Production on 05-MAR-2019 01:52:41 Copyright (c) 1991, 2018, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP) (HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 18.0.0.0.0 - Production Start Date 03-MAR-2019 23:30:55 Uptime 1 days 2 hr. 21 min. 45 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/18.0.0 /dbhome_1/network /admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr /slc12ftw/listener /alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp) (HOST=host01.us.oracle.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host01.example.com) (PORT=5500))(Security=(my_wallet_directory=/scratch/u01/app /oracle/admin/orcl/xdb_wallet)) (Presentation=HTTP)(Session=RAW)) Services Summary... Service "orcl.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclXDB.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... The command completed successfullyLSNRCTL for Linux: Version 19.0.0.0.0 - Production on 15-JUL-2019 01:09:40 Copyright (c) 1991, 2019, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=host01.example.com)(PORT=1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production Start Date 10-JUL-2019 01:32:04 Uptime 4 days 23 hr. 37 min. 36 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /scratch/u01/app/oracle/product/19.0.0/dbhome_1/network/admin/listener.ora Listener Log File /scratch/u01/app/oracle/diag/tnslsnr/host01/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host01.example.com)(PORT=1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=host01.example.com)(PORT=5500))(Security=(my_wallet_directory=/scratch/u01/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW)) Services Summary... Service "86b637b62fdf7a65e053f706e80a27ca.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "8d50ba5e384412fbe053193ec40a5c2c.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orcl.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclXDB.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... Service "orclpdb.us.oracle.com" has 1 instance(s). Instance "orcl", status READY, has 1 handler(s) for this service... The command completed successfully
Note: If the PDB is configured, you will see a service for each PDB.
- Once again log in to SQL*Plus as the SYSTEM
user to verify you can now connect to the database.
$ sqlplus system@orclSQL*Plus: Release 18.0.0.0.0 Production on Mon Mar 07 07:14:15 2019 Copyright (c) 1982, 2018, Oracle. All rights reserved. Enter password: Enter password here Last Successful login time: Mon Jul 25 2016 07:31:56 +00:00 Connected to: Oracle Database 18c Enterprise Edition Release 18.0.0.0.0 - Production Version 18.3.0.0.0SQL*Plus: Release 19.0.0.0.0 - Production on Mon Jul 15 03:01:37 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle. All rights reserved. Enter password: Last Successful login time: Mon Jul 15 2019 03:01:34 -07:00 Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.3.0.0.0 SQL>
- Log in to Enterprise Manager Database Express as the SYSTEM
user to verify you can access the database.
Description of this image 
Description of this image - The Database Home page is displayed. Log out of Enterprise Manager Database Express.