1.先决条件
DGMGRL> ENABLE FAST_START FAILOVER;
Error: ORA-: requirements not met for enabling fast-start failover
[oracle@vijay02 ~]$ oerr ora
, , "requirements not met for enabling fast-start failover"
// *Cause: The attempt to enable fast-start failover could not be completed
// because one or more requirements were not met:
// - The Data Guard configuration must be in either MaxAvailability
// or MaxPerformance protection mode.
// - The LogXptMode property for both the primary database and
// the fast-start failover target standby database must be
// set to SYNC if the configuration protection mode is set to
// MaxAvailability mode.
// - The LogXptMode property for both the primary database and
// the fast-start failover target standby database must be
// set to ASYNC if the configuration protection mode is set to
// MaxPerformance mode.
// - The primary database and the fast-start failover target standby
// database must both have flashback enabled.
// - No valid target standby database was specified in the primary
// database FastStartFailoverTarget property prior to the attempt
// to enable fast-start failover, and more than one standby
// database exists in the Data Guard configuration.
// *Action: Retry the command after correcting the issue:
// - Set the Data Guard configuration to either MaxAvailability
// or MaxPerformance protection mode.
// - Ensure that the LogXptMode property for both the primary
// database and the fast-start failover target standby database
// are set to SYNC if the configuration protection mode is set to
// MaxAvailability.
// - Ensure that the LogXptMode property for both the primary
// database and the fast-start failover target standby database
// are set to ASYNC if the configuration protection mode is set to
// MaxPerformance.
// - Ensure that both the primary database and the fast-start failover
// target standby database have flashback enabled.
// - Set the primary database FastStartFailoverTarget property to
// the DB_UNIQUE_NAME value of the desired target standby database
// and the desired target standby database FastStartFailoverTarget
// property to the DB_UNIQUE_NAME value of the primary database.
2.设置参数
a.设置日志同步传输模式
edit database patest set property logxptmode=sync;
edit database satest set property logxptmode=sync;
b.设置保护模式（MaxAvailability or MaxPerformance）
edit configuration set protection mode as maxavailability;
c.设置主库故障的转移对象
edit database patest set property FastStartFailoverTarget='satest';
edit database satest set property FastStartFailoverTarget='patest';
d.主备库设置闪回
3.启用FAST_START FAILOVER
ENABLE FAST_START FAILOVER;
查看状态
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
patest - Primary database
Warning: ORA-: fast-start failover observer not started satest - (*) Physical standby database
Warning: ORA-: fast-start failover observer not started Fast-Start Failover: ENABLED --已开启 Configuration Status:
WARNING
因为没有开启监听器，所以出现警告。
4.开启监听器（监听器可以设置在独立的服务器上，也可以设置为某个节点上，本问设置在节点备库上）
（如果设置在独立的服务器上，要求服务器设置静态监听，和oracle软件）
DGMGRL> START OBSERVER
Observer started
.......
以上是开启监听器的命令，监听器开启后，界面无法返回。
以下是dgmgrl状态信息
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
patest - Primary database
satest - (*) Physical standby database Fast-Start Failover: ENABLED --已开启，没有警告信息，配置文件状态为SUCCUSS Configuration Status:
SUCCESS
5.模拟自动故障转移
a.假设主库故障（shutdown abort）
b监听器提示
DGMGRL> START OBSERVER
Observer started ::16.05 Wednesday, December ,
Initiating Fast-Start Failover to database "satest"...
Performing failover NOW, please wait...
Failover succeeded, new primary is "satest"
::19.50 Wednesday, December ,
以上提示，已自动启用备库为主库
c.dgmgrl状态信息
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
satest - Primary database
Warning: ORA-: unsynchronized fast-start failover configuration patest - (*) Physical standby database (disabled)
ORA-: the standby database needs to be reinstated Fast-Start Failover: ENABLED Configuration Status:
WARNING
d.尝试修复故障库，把故障库启动到mount状态
e.监听器自动开始修复故障库
DGMGRL> START OBSERVER
Observer started ::16.05 Wednesday, December ,
Initiating Fast-Start Failover to database "satest"...
Performing failover NOW, please wait...
Failover succeeded, new primary is "satest"
::19.50 Wednesday, December , ::02.03 Wednesday, December ,
Initiating reinstatement for database "patest"...
Reinstating database "patest", please wait...
Operation requires shutdown of instance "atest" on database "patest"
Shutting down instance "atest"...
Unable to connect to database
ORA-: Connect failed because target host or object does not exist Failed.
Warning: You are no longer connected to ORACLE. Please complete the following steps and reissue the REINSTATE command:
shut down instance "atest" of database "patest"
start up and mount instance "atest" of database "patest" ::20.82 Wednesday, December ,
f.根据监听器提示重启故障库至mount
g.查看dgmgrl状态信息
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
satest - Primary database
Warning: ORA-: unsynchronized fast-start failover configuration patest - (*) Physical standby database (disabled)
ORA-: the standby database needs to be reinstated Fast-Start Failover: ENABLED Configuration Status:
WARNING
h.reinstate故障库
DGMGRL> reinstate database patest;
Reinstating database "patest", please wait...
Reinstatement of database "patest" succeeded
i.查看dgmgrl状态信息
DGMGRL> reinstate database patest;
Reinstating database "patest", please wait...
Reinstatement of database "patest" succeeded
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
satest - Primary database
patest - (*) Physical standby database Fast-Start Failover: ENABLED Configuration Status:
SUCCESS
状态已恢复。
6.关闭自动故障转移
DGMGRL> stop observer
Done.
DGMGRL> disable fast_start failover;
Disabled.
查看dgmgrl状态信息
DGMGRL> show configuration; Configuration - dgc Protection Mode: MaxAvailability
Databases:
satest - Primary database
patest - Physical standby database Fast-Start Failover: DISABLED --已禁用 Configuration Status:
SUCCESS
7.小结：
快速故障转移可能会导致数据丢失，慎用！
监听器最好设置在独立的服务器上！