DGbroker快速失败转移

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！