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Oracle11gR2DataGuard环境BROKER配置Fast-StartFailover
Oracle11gR2DataGuard环境BROKER配置Fast-StartFailover
时间:2021-07-01 10:21:17
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FAST-START failover 就是在当主数据库出现故障时,能快速与可靠的把standby切换成主数据库,在整个过程中不需要人来干预。fast-
FAST-START failover 就是在当主数据库出现故障时,能快速与可靠的把standby切换成主数据库,在整个过程中不需要人来干预。fast-start failover只能通过dgmgrl与Enterprise Managerg来配置。
只有maximum availability mode or maximum performance mode才能启用fast-start failover模式。在maximum availability模式下面,在切换时可以保证无数据丢失,在maximum performance mode下面,会有数据丢失,丢失多少数据由 FastStartFailoverLagLimit这个参数来配置。
只要observer进程启动过,我们就不需要人为的干预。当observer与指定的备数据库与主数据库失去连接的时间超过FastStartFailoverThreshold后,,observer就会启动fast-start failover 到备数据库。如果配置了FastStartFailoverPmyShutdown为true,此时原来的主数据库将会自动的shutdown。如果配置FastStartFailoverAutoReinstate为true,当failover完成后,启动数据库时,会自动的执行Reinstate database,把原来的主数据库变成备库,并与新主库进行同步。
fast-start failover包含3个过程,如下图:
测试开始:
环境:OS RedHat 5.6 X86_64 ,DB 11.2.0.2
1,DG环境的搭建。
见Oracle 11GR2 搭建活动的物理DG/DataGuard (READ ONLY模式)
2,broker的配置
见
3,配置保护模式与日志传递方式
之前已经说了FAST-START FAILOVER只 maximum availability mode与maximum performance mode
下面我们看一下每一种保护模式对应的日志传递方式。
3.1修改保护模式:
3.2 修改日志传递方式
4 配置数据库的flashback
4.1 主库上面
4.2 备库上面
5 配置observer服务器
5.1 配置tnsnames.ora文件。
[oracle@test admin]$ cat tnsnames.ora HTZB = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.31)(PORT = 1521)) ) (CONNECT_DATA = (SERVER = dedicate) (SERVICE_NAME = htzb) ) ) HTZ = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.30)(PORT = 1521)) ) (CONNECT_DATA = (SERVER = dedicate) (SERVICE_NAME = htz) ) )
5.2 启动observer进程
6 配置fast-start failover
于fst-start failove相关的其它几个参数:
FastStartFailoverPmyShutdown
FastStartFailoverLagLimit
FastStartFailoverAutoReinstate
ObserverConnectIdentifier
这里我们都使用默认值;我们来看一下这些值的默认值;
7 启用fast-start failover
8.测试FAST-START FAILOVER是否生效
DGMGRL> show configuration
Configuration - htz
Protection Mode: MaxAvailability
Databases:
htz - (*) Physical standby database
Fast-Start Failover: ENABLED
Configuration Status:
SUCCESS
#原主库直接shutdown abort;
SQL> shutdown abort;
ORACLE instance shut down.
SQL>
#observer进程的日志
19:03:03.93 Friday, September 07, 2012
Initiating Fast-Start Failover to database "htz"...
Performing failover NOW, please wait...
Failover succeeded, new primary is "htz"
19:03:13.24 Friday, September 07, 2012
#提示已经把主切换到htz
#在htz上面查看一下
OPEN_MODE DATABASE_ROLE
已经成功
手动启动原主库
DGMGRL> show configuration;
Configuration - htz
Protection Mode: MaxAvailability
Databases:
htz - Primary database
Warning: ORA-16817: unsynchronized fast-start failover configuration
htzb - (*) Physical standby database (disabled)
ORA-16661: the standby database needs to be reinstated
Fast-Start Failover: ENABLED
Configuration Status:
WARNING
DGMGRL> connect sys/oracle@htzb
Connected.
DGMGRL> startup
ORACLE instance started.
Database mounted.
ORA-16649: possible failover to another database prevents this database from being opened
#过一分会后我们再查看一下状态
DGMGRL> connect sys/oracle@htz
Connected.
DGMGRL> show configuration
Configuration - htz
Protection Mode: MaxAvailability
Databases:
htz - Primary database
htzb - (*) Physical standby database
Fast-Start Failover: ENABLED
Configuration Status:
SUCCESS
查看状态,一切正常。