11Copyright © 2005, Oracle. All rights reserved.

Configuring the Oracle Network Environment

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Objectives

After completing this lesson, you should be able to:

• Use Enterprise Manager to:– Create additional listeners– Create Oracle Net Service aliases– Configure connect-time failover– Control the Oracle Net Listener

• Use Oracle Net Manager to configure client and middle-tier connections

• Use tnsping to test Oracle Net connectivity

• Identify when to use shared servers versus dedicated servers

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Oracle Net Services

Application

Oracle Net

RDBMS

Oracle Net

Client or middle tier

Database server

TCP/IP network

Listener

Oracle Net configuration files

Oracle Net configuration files

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Tools for Configuring and Managing the Oracle Network

• Enterprise Manager Net Services Administration page

• Oracle Net Manager

• Oracle Net Configuration Assistant launched by Oracle Universal Installer

• Command Line

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Listener Control Utility

Oracle Net listeners can be controlled with the command-line lsnrctl utility.$lsnrctl

LSNRCTL for Linux: Version 10.2.0.0.0 on 12-MAY-2005 13:27:51

Copyright (c) 1991, 2004, Oracle. All rights reserved.

Welcome to LSNRCTL, type "help" for information.

LSNRCTL> help

The following operations are available

An asterisk (*) denotes a modifier or extended command:

start stop status

services version reload

save_config trace spawn

change_password quit exit

set* show*

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Listener Control Utility Syntax

Commands from the listener control utility can be issued from the command line or from the LSNRCTL prompt.

• UNIX or Linux command-line syntax:

• Prompt syntax:

# lsnrctl <command name>

# lsnrctl start

# lsnrctl status

LSNRCTL> <command name>

LSNRCTL> start

LSNRCTL> status

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Listener Home Page

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Net Services Administration Pages

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Oracle Net Listener

Listener

<oracle_home>/network/admin/listener.ora sqlnet.ora

Oracle database(s)

Oracle Net configuration files

Enterprise ManagerDatabaseControl

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Creating a Listener

1

2

3

4

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Adding Listener Addresses

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Database Service Registration

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Where We Are

• Learning how to use Enterprise Manager to:– Create and monitor listeners– Add listening addresses– Edit database service registration

• Establishing connections—choose/configure:– Names Resolution – Oracle Net Service aliases– Connect-time failover– Load balancing (RAC)– Source routing

• Using Oracle Net Manager• Testing Oracle Net connectivity• Identifying when to use shared servers versus

dedicated servers

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Establishing Net Connections

To make a client or middle-tier connection, Oracle Net requires the client to know the:

• Host where the listener is running

• Port that the listener is monitoring

• Protocol that the listener is using

• Name of the service that the listener is handling

Names Resolution

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Naming Methods

Oracle Net supports several methods of resolving connection information:• Easy connect naming: Uses a TCP/IP connect

string• Local naming: Uses a local configuration file• Directory naming: Uses a centralized

LDAP-compliant directory server• External naming: Uses a supported non-Oracle

naming service

Client/application serverOracle Net

Oracle Net configuration files

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Easy Connect

• Is enabled by default• Requires no client-side configuration• Supports only TCP/IP (no SSL)• Offers no support for advanced connection

options, such as:– Connect-time failover– Source routing– Load balancing

SQL> CONNECT hr/hr@db.us.oracle.com:1521/dba10g

No Oracle Net configuration files

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Local Naming

• Requires a client-side Names Resolution file

• Supports all Oracle Net protocols

• Supports advanced connection options, such as:– Connect-time failover– Source routing– Load balancing

SQL> CONNECT hr/hr@orcl

Oracle Net configuration files

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Directory Naming

• Requires LDAP with Oracle Net Names Resolution information loaded:– Oracle Internet Directory– Microsoft Active Directory Services

• Supports all Oracle Net protocols• Supports advanced connection options

SQL> CONNECT hr/hr@orcl

LDAP directory

Oracle Net configuration files

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External Naming Method

• Uses a supported non-Oracle naming service

• Includes:– Network Information Service (NIS) External Naming– Distributed Computing Environment (DCE) Cell

Directory Services (CDS)

Oracle Net

Non-Oracle naming service

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Configuring Service Aliases

Create oredit

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Advanced Connection Options

Oracle Net supports the following advanced connection options with local and directory naming:

• Connect-time failover

• Load balancing

• Source routing

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Where We Are

• Learning how to use Enterprise Manager to:– Create and monitor listeners– Add listening addresses– Edit database service registration

• Establishing connections—choose/configure:– Names Resolution– Oracle Net Service aliases– Connect-time failover– Load balancing (RAC)– Source routing

• Using Oracle Net Manager• Testing Oracle Net connectivity• Identifying when to use shared servers versus

dedicated servers

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Oracle Net Manager

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Choosing Naming Methods

Oracle Net Manager configures the Names Resolution methods for a client or middle tier and the order in which they are checked.

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Configuring Service Naming with Net Manager

Step 1: Net Service Name Step 2: Protocol

Step 4: Service

Step 3: Protocol Setting

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Configuring Service Naming with Net Manager

Step 5: Test

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Using Oracle Net Manager to Select Advanced Connection Options

Oracle Net supports the following advanced connection options with local and directory naming:• Connect-time failover• Load balancing• Source routing

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Testing Oracle Net Connectivity

The tnsping utility that tests Oracle Net service aliases:

• Ensures connectivity between the client and the Oracle Net Listener

• Does not verify that the requested service is available

• Supports Easy Connect Names Resolution:

• Supports local and directory naming:

tnsping db.us.oracle.com:1521/dba10g

tnsping orcl

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Where We Are

• Using Enterprise Manager to configure Oracle Network components

• Using Oracle Net Manager

• Testing Oracle Net connectivity

• Identifying when to use shared servers versus dedicated servers

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Listener

Establishing a Connection

Incoming connection request

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Serverprocess

User Sessions

PGA

Listener

User session

User process

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User Sessions: Dedicated Server

User sessions

Server process

Server process

Server process

User session

Server process

Server process

Server process

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User Sessions: Shared Servers

Listener

Dispatcher

Serverprocess

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Response queue for D001

Response queue for D002

InstanceSGA

Shared serverprocesses

S001

S002

S000 Response queue for D000

Processing a Request with Shared Servers

2

3

4

5

Common request queue

for alldispatchers

Database server

Client or middle tierUser

process

DispatcherD001

DispatcherD002

DispatcherD000

1

6

Userprocess

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SGA

SGA

Largepool and other memory structures

Large pool and other memory

structures

Stackspace

PGA

SGA and PGA

User session

data

Cursorstate

Dedicated server: User session data is kept in the PGA.

Oracle Shared Server: User session data is held in the SGA.

PGA

User session

data

Cursor state

Stackspace

Sort data

Sortdata

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Shared Server: Connection Pooling

The client application has been idle past the specified time, and an incoming client requests a

connection.

The maximum number of connections is configured to 255.This client connection is the 256th

connection into the server. Connection pooling is turned on, so that this connection can be accepted.

Database

server

Idle client

Active client

New client

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When Not to Use a Shared Server

Certain types of database work must not be performed by using shared servers:

• Database administration

• Backup and recovery operations

• Batch processing and bulk load operations

• Data warehouse operations

Dispatcher Server process

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Oracle Connection Manager (CMAN): Overview

• Oracle Connection Manager typically resides on a separate server.

• It functions as a net traffic firewall and proxy server.

• It can be configured to perform:– Access control filtering– Session multiplexing– Protocol conversion

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Client

Web browser

Web browser

Web browser

Multiplexing Sessions

ApplicationWeb server

OracleConnection

Manager

Databaseserver

Intranet

RDBMS

OracleNet

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Summary

In this lesson, you should have learned how to:

• Use Enterprise Manager to:– Create additional listeners– Create Oracle Net Service aliases– Configure connect-time failover– Control the Oracle Net Listener

• Use Oracle Net Manager to configure client and middle-tier connections

• Use tnsping to test Oracle Net connectivity

• Identify when to use shared servers versus dedicated servers

11-43 Copyright © 2005, Oracle. All rights reserved.

Practice Overview: Working with Oracle Network Components

This practice covers:

• Configuring local Names Resolution to connect to another database

• Creating a second listener for connect-time failover