DGbroker快速失败转移

1.先决条件

DGMGRL>  ENABLE FAST_START FAILOVER;
Error: ORA-16651: requirements not met for enabling fast-start failover

[oracle@vijay02 ~]$ oerr ora 16651
16651, 0000, "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-16819: fast-start failover observer not started

    satest - (*) Physical standby database
      Warning: ORA-16819: 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

23:42:16.05  Wednesday, December 30, 2015
Initiating Fast-Start Failover to database "satest"...
Performing failover NOW, please wait...
Failover succeeded, new primary is "satest"
23:42:19.50  Wednesday, December 30, 2015

　　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-16817: unsynchronized fast-start failover configuration

    patest - (*) Physical standby database (disabled)
      ORA-16661: 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

23:42:16.05  Wednesday, December 30, 2015
Initiating Fast-Start Failover to database "satest"...
Performing failover NOW, please wait...
Failover succeeded, new primary is "satest"
23:42:19.50  Wednesday, December 30, 2015

23:46:02.03  Wednesday, December 30, 2015
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-12545: 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"

23:46:20.82  Wednesday, December 30, 2015

　　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-16817: unsynchronized fast-start failover configuration

    patest - (*) Physical standby database (disabled)
      ORA-16661: 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！