RAC到单实例SWITCHOVER

                              RAC到单实例SWITCHOVER

   现有RAC(12C)到单实例的物理DATAGUARD，需要SWITCHOVER主库到单实例上 ，使原来的
RAC成为备库，单实例备库成为主库.

   在rac和单实例备库上检查DG的相关参数，确认无误.

在RAC上，手动实现switch logfile,然后检查备库是已经应用了相用的logfile,以确保事务
完全在备库上应用。

 

SQL> alter system switch logfile;

System altered.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/product/12.1.0.0/db_1/dbs/arch
Oldest online log sequence     69
Next log sequence to archive   70
Current log sequence           70
SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PRIMARY

 

DG备库上检查

SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PHYSICAL STANDBY

SQL> select process,client_process,thread#,sequence# from v$managed_standby;

PROCESS   CLIENT_P    THREAD#  SEQUENCE#
--------- -------- ---------- ----------
ARCH      ARCH              1         68
ARCH      ARCH              1         64
ARCH      ARCH              0          0
ARCH      ARCH              1         69
RFS       UNKNOWN           0          0
RFS       ARCH              0          0
RFS       LGWR              2         30
RFS       UNKNOWN           0          0
RFS       LGWR              1         70
RFS       ARCH              0          0
RFS       UNKNOWN           0          0

PROCESS   CLIENT_P    THREAD#  SEQUENCE#
--------- -------- ---------- ----------
RFS       UNKNOWN           0          0
MRP0      N/A               1         70

13 rows selected.

在rac主库上执行

SQL> alter database commit to switchover to physical standby;

Database altered.
SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PHYSICAL STANDBY

在dg备库提升为主库.
SQL> alter database commit to switchover to primary;

Database altered.

SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PRIMARY

打开单实例数据库

SQL> alter database open;

Database altered.

在11.2的版本中在SWITCHOVER时，不需要再更改cluster_database参数重启数据库了，这一点
比原来方便很多.

在rac节点上启动日志应用.

SQL> alter database recover managed standby database disconnect from session;

Database altered.

SQL> select open_mode from v$database;

OPEN_MODE
--------------------
READ ONLY WITH APPLY             --default已经使用active dataguard了.

在单实例主库上手动切换日志，检查在rac备库上应用情况，确认DATAGUARD工作正常.