Using the Listener Control Utility to Manage the Listener

Overview

Purpose

This tutorial introduces you to the Listener Control utility which enables you to administer the listener.

Time to Complete

Approximately 30 minutes

Introduction

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.

Software Requirements

The following is a list of software requirements:

  • Oracle Database 12c

Prerequisites

Before starting this tutorial, you should have installed Oracle Database 12c and created a database.

Viewing 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:

  1. Open a terminal window and execute the oraenv command to set the environment variables.

  2. Execute the lsnrctl status command.

Starting 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. To restart the listener, perform the following steps:

  1. For the purposes of this tutorial, stop the listener by executing the lsnrctl stop command.

  2. 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.

  3. Also try to log in to Enterprise Manager Database Express as the SYSTEM user. (If your login page is not already open, the login page might not display when the listener goes down.)

  4. Restart the listener by using the lsnrctl start command.

  5. Check the listener status by executing the lsnrctl status command.

  6. Once again log in to SQL*Plus as the SYSTEM user to verify you can now connect to the database.

  7. Log in to Enterprise Manager Database Express as the SYSTEM user to verify you can access the database.

  8. The Database Home page is displayed. Log out of Enterprise Manager Database Express.

Summary

In this tutorial, you learned to:

  • View the status of the listener
  • Start the listener

Resources

  • Oracle Database 2 Day DBA 12c Release 2 (12.1.0.2)
  • Oracle Database Net Services Administrator's Guide 12c Release 1 (12.1)
  • Oracle Database Net Services Reference 12c Release 1 (12.1)

Credits

  • Lead Curriculum Developer: Veerabhadra Rao Putrevu
  • Original Curriculum Developers: Donna Keesling, Salome Clement
  • Other Contributors: Bert Rich

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