Oracle学习之DATAGUARD(六) 创建和启用Broker配置

DataGuard Broker是一个分布式管理架构用于自动创建、维护和监视dataguard配置。你可以使用OEM(图像化界面)或者DGMGRL(命令行方式)进行以下操作：
1。创建和激活dataguard配置，包括设置redo transport services and log apply services
2。可以在任何系统管理这个配置中的整个dataguard配置(所有的主库和备库)
3。管理和监视包含RAC primary或standby数据库的dataguard配置
4。简化角色切换操作，只要DGMGRL的一条命令或者OEM的一个按钮就可以进行switchover或failover
5。可以激活fast-start failover以自动进行fail over当主库不可用时。当此功能被激活，Data Guard broker决定failover是否必需，并开始自动failover到指定的目标standby数据库，不需要DBA干涉，也不会丢失数据。
下面我们演示一下，Broker如何创建和启用Broker配置。
一、 启用DataGuard Broker
在主从数据库上都需执行如下两步。
1.1 启用dg_broker

SQL> ALTER SYSTEM SET dg_broker_start=TRUE SCOPE=BOTH;

System altered.

检查后台进程，你会发现Oracle多启动了一个进程

11gdg1-> ps -ef | grep ora_dmon
oracle   19675     1  0 03:43 ?        00:00:00 ora_dmon_dgtst

1.2 配置静态监听器。
注：数据库上一定要配置listener的静态监听，并且GLOBAL_NAME要指定为db_unique_name_DGMGRL.domain

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = 11gdg1_DGMGRL)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_1)
(SID_NAME = dgtst)
)
)

二、使用dgmgrl
2.1 查看dgmgrl帮助

11gdg1-> dgmgrl
DGMGRL for Linux: Version 11.2.0.3.0 - 64bit Production

Copyright (c) 2000, 2009, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
DGMGRL> help

The following commands are available:

add            Adds a standby database to the broker configuration
connect        Connects to an Oracle database instance
convert        Converts a database from one type to another
create         Creates a broker configuration
disable        Disables a configuration, a database, or fast-start failover
edit           Edits a configuration, database, or instance
enable         Enables a configuration, a database, or fast-start failover
exit           Exits the program
failover       Changes a standby database to be the primary database
help           Displays description and syntax for a command
quit           Exits the program
reinstate      Changes a database marked for reinstatement into a viable standby
rem            Comment to be ignored by DGMGRL
remove         Removes a configuration, database, or instance
show           Displays information about a configuration, database, or instance
shutdown       Shuts down a currently running Oracle database instance
sql            Executes a SQL statement
start          Starts the fast-start failover observer
startup        Starts an Oracle database instance
stop           Stops the fast-start failover observer
switchover     Switches roles between a primary and standby database

Use "help <command>" to see syntax for individual commands

2.2 连接到数据库
使用dgmgrl进行任何数据库操作时，必须先连接到数据库。

DGMGRL> help connect

Connects to an Oracle database instance

Syntax:

CONNECT <username>/<password>[@<connect identifier>]

连接到主库

DGMGRL> connect sys/oracle@11gdg1
Connected.

2.3 创建一个broker的配置文件

DGMGRL> help create

Creates a broker configuration

Syntax:

CREATE CONFIGURATION <configuration name> AS
PRIMARY DATABASE IS <database name>
CONNECT IDENTIFIER IS <connect identifier>;

此步骤一定要在主库上执行,<database name>指定的是DB_UNIQUE_NAME,而不是DB_NAME

DGMGRL> CREATE CONFIGURATION DR1 AS PRIMARY DATABASE IS 11gdg1 CONNECT IDENTIFIER IS 11GDG1;
Configuration "dr1" created with primary database "11gdg1"

此时，我们只是创建了一个配置，该配置存储在主数据库的配置文件中，但是我们既没有加入standby数据，也没有使配置生效。我们可以使用SHOW CONFIGURATION 查看配置。

DGMGRL> show configuration;

Configuration - dr1

Protection Mode: MaxPerformance
Databases:
11gdg1 - Primary database

Fast-Start Failover: DISABLED

Configuration Status:
DISABLED

2.4 将从库添加到配置中

DGMGRL> ADD DATABASE 11GDG2;
Database "11gdg2" added

因为在主库上已经配置了LOG_ARCHIVE_DEST_2，如下。

SQL> show parameter log_archive_dest_2

NAME	             TYPE      VALUE
------------------ --------- ------------------------------
log_archive_dest_2 string    service=11gdg2 ASYNC DB_UNIQUE_NAME=11gdg2 VALID_FOR=(primary_role,online_logfile)

所以添加从库执行执行

ADD DATABASE 11GDG2;

即可，如果没有配置的话，需要指定完整的信息。

ADD DATABASE 11gdg2 AS CONNECT IDENTIFIER IS 11gdg2  MAINTAINED AS PHYSICAL;

查看配置信息

DGMGRL> show configuration

Configuration - dr1

Protection Mode: MaxPerformance
Databases:
11gdg1 - Primary database
11gdg2 - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
DISABLED

standby已经被添加到配置中。
2.4 查看数据库DG配置的详细信息

DGMGRL> show database verbose 11gdg1;

Database - 11gdg1

Role:            PRIMARY
Intended State:  OFFLINE
Instance(s):
dgtst

Properties:
DGConnectIdentifier             = '11gdg1'
ObserverConnectIdentifier       = ''
LogXptMode                      = 'ASYNC'
DelayMins                       = '0'
Binding                         = 'optional'
MaxFailure                      = '0'
MaxConnections                  = '1'
ReopenSecs                      = '300'
NetTimeout                      = '30'
RedoCompression                 = 'DISABLE'
LogShipping                     = 'ON'
PreferredApplyInstance          = ''
ApplyInstanceTimeout            = '0'
ApplyParallel                   = 'AUTO'
StandbyFileManagement           = 'AUTO'
ArchiveLagTarget                = '0'
LogArchiveMaxProcesses          = '4'
LogArchiveMinSucceedDest        = '1'
DbFileNameConvert               = ''
LogFileNameConvert              = ''
FastStartFailoverTarget         = ''
InconsistentProperties          = '(monitor)'
InconsistentLogXptProps         = '(monitor)'
SendQEntries                    = '(monitor)'
LogXptStatus                    = '(monitor)'
RecvQEntries                    = '(monitor)'
SidName                         = 'dgtst'
StaticConnectIdentifier         = '(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=11gdg1.localdomain.com)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=11gdg1_DGMGRL)(INSTANCE_NAME=dgtst)(SERVER=DEDICATED)))'
StandbyArchiveLocation          = 'USE_DB_RECOVERY_FILE_DEST'
AlternateLocation               = ''
LogArchiveTrace                 = '0'
LogArchiveFormat                = '%t_%s_%r.dbf'
TopWaitEvents                   = '(monitor)'

Database Status:
DISABLED

2.5 使CONFIGURATION生效

DGMGRL> ENABLE CONFIGURATION;
Enabled.
DGMGRL> SHOW CONFIGURATION;

Configuration - dr1

Protection Mode: MaxPerformance
Databases:
11gdg1 - Primary database
11gdg2 - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS