3 Using Data Guard Broker and Enterprise Manager

After completing this lesson, you should be able to do the following: • Describe the Data Guard broker architecture • Describe the Data Guard broker components • Explain the benefits of

Using Data Guard Broker and Enterprise Manager

After completing this lesson, you should be able to do the following:

• Describe the Data Guard broker architecture

• Describe the Data Guard broker components

• Explain the benefits of the Data Guard broker

• Explain Data Guard broker configurations

• Use Enterprise Manager to manage your Data Guard

configuration

• Invoke DGMGRL to manage your Data Guard

configuration

Features of Data Guard Broker

• The Data Guard broker is a distributed management

framework.

• The broker automates and centralizes the creation,

maintenance, and monitoring of Data Guard

configurations.

• With the broker, you can perform all management

operations locally or remotely through easy-to-use interfaces:

– Oracle Enterprise Manager 10g Grid Control

– A command-line interface: DGMGRL

Data Guard Broker: Components

Data Guard Broker: Configurations

The most common configuration is a primary database at one location and a standby database at another location.

Chicago

Primary site

Boston

Standby site Oracle Net

Data Guard Broker: Management Model

Data Guard Broker Configuration

Primary database

Broker-controlled databases

Standby database Standby database Standby database Standby database Standby database Standby database Standby database Standby database Standby database Instances Instances

Primary site

Standby site 9 Standby site 2

Data Guard Broker: Architecture

Graphical user interface

or command-line interface

DMON

Archived redo logs

Online

redo logs

Standby site 1

Oracle Net

Standby redo logs Archived

redo logs

Log apply services Data Guard Configuration

Log transport services

Life Cycle of a Broker Configuration

Create configuration

Enable configuration

Make state or role changes

Update database properties

Monitor and tune configuration

Data Guard Broker: Requirements

• Enterprise Edition of Oracle Database 10g

• Single-instance or multi-instance environment

• COMPATIBLE must be set to 9.2.0.1.0 or higher for

primary and standby databases.

• Oracle Net network files must be configured for

databases that you add to the configuration.

• LOCAL_LISTENER on each instance must resolve to an

address that is reachable by all members.

• GLOBAL_DBNAME attribute must be set to a

concatenation of:

db_unique_name_DGMGRL.db_domain

Data Guard Broker: Requirements

• DG_BROKER_START = TRUE

• The primary database must be in ARCHIVELOG mode.

• All databases must be in MOUNT or OPEN mode.

• Configure DG_BROKER_CONFIG_FILEn for any RAC

databases.

• START_OPTIONS for any RAC databases must be set to

MOUNT in the Oracle Cluster Repository (OCR).

Data Guard Broker and the SPFILE

• You must use a server parameter file (SPFILE) for

initialization parameters.

• Using the SPFILE enables the Data Guard broker to

keep its configuration file and the database SPFILE consistent.

• If you use the broker, use Enterprise Manager or

DGMGRL to update database parameter values.

Data Guard Monitor: DMON Process

• Server-side background process

• Part of each database instance in the configuration

• Created when you start the broker

• Performs requested functions and monitors the

Data Guard Monitor: Configuration File

• Automatically created and named using a default path name and file name when the broker is started

• Override default path name and file name by setting

DG_BROKER_CONFIG_FILEn

• Two files at each managed site

• Managed automatically by the DMON process

• Default names are dr1<db_unique_name>.dat and dr2<db_unique_name>.dat.

• Default locations are operating system specific:

– Default location for UNIX and Linux: ORACLE_HOME/dbs

– Default location for Windows: ORACLE_HOME\database

Benefits of Using the Data Guard Broker

• Enhances the high-availability, data protection, and

disaster protection capabilities inherent in Oracle Data Guard by automating both configuration and

monitoring tasks

• Streamlines the process for any one of the standby

databases to replace the primary database and take over production processing

• Helps you logically define and create a Data Guard

configuration consisting of a primary database and a standby database

• Enables easy configuration of additional standby

databases

Benefits of Using the Data Guard Broker

• Provides simplified, centralized, and extended

management

• Automates switchover and failover to a specified

standby database in the broker configuration

• Automatically communicates between the databases in

a Data Guard configuration using Oracle Net Services

• Provides built-in validation that monitors the health of

all the databases in the configuration

Data Guard Broker Interfaces

• Oracle Enterprise Manager 10g Grid Control:

standby databases

• Command-line interface (CLI):

where the Oracle server is installed

configuration from the CLI prompt or in scripts

Using Oracle Enterprise Manager 10g

Grid Control

Click “Setup and Manage” to access the Data Guard pages.

Data Guard Overview Page

Enterprise Manager Metrics and Alerts

• Metrics: Units of measurement used to assess the

health of your system

• Thresholds: Boundary values against which monitored

metric values are compared

• Alert: Generated when a threshold is reached

Using Data Guard Metrics

Enterprise Manager includes the following Data Guard metrics:

• Data Guard Fast-Start Failover

• Data Guard Fast-Start Failover

Observer

• Data Guard Performance

• Data Guard Status

Managing Data Guard Metrics

1 Configure notification methods.

2 View the All Metrics page.

3 Set or change Data Guard metric thresholds.

4 View triggered metrics.

Benefits of Using Enterprise Manager

• Enables you to manage your configuration using a

familiar interface and event-management system

• Automates and simplifies the complex operations of

creating and managing standby databases through the use of wizards

• Performs all Oracle Net Services configuration changes that are necessary to support redo transport services and log apply services

• Provides a verify operation to ensure that redo

transport services and log apply services are

configured and functioning properly

• Enables you to select a new primary database from a

Using the Command-Line Interface

of the Data Guard Broker

Protection Mode: MaxPerformance

Fast-Start Failover: DISABLED

Databases:

EDRSR8P1_ORCL - Primary database

EDRSR8P1_SITE1 - Physical standby database EDRSR8P1_SITE2 - Logical standby database Current status for "EDRSR8P1_ORCL.oracle.com": SUCCESS

In this lesson, you should have learned how to:

• Describe the Data Guard broker management model

• Describe the Data Guard broker architecture

• Describe Data Guard broker components

• Access Enterprise Manager

• Invoke DGMGRL (the Data Guard CLI)