Data Guard 主备库角色转换-白红宇

Data Guard 主备库角色转换

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发布时间：2019-06-26

本文共 2105 字，大约阅读时间需要 7 分钟。

1. switchover操作

1.1 备库先关闭实时日志应用

standby>alter database recover managed standby database cancel;

1.2 主库先判断是否可以支持switchover操作

primary> select switchover_status from v$database;

该值为：TO STANDBY；表示支持。

该值为：SESSION ACTIVE；表示主库有激活会话。不妨碍switchover操作。

1.3 启动switchover；主库转换physical standby。

若上值为第二种情况；后面需加 with shutdown session

即 alter database commit to switchover to physical standby with shutdown session;

primary> alter database commit to switchover to physical standby;Database altered.

1.4 重启原primary库

Primary> shutdown immediate;ORA- 01507 : database not mountedORACLE instance shut down.Primary> startupORACLE instance started.Total System Global Area 1.5132E+10 bytesFixed Size            2243112 bytesVariable Size         2013267416 bytesDatabase Buffers     1.3086E+10 bytesRedo Buffers           30552064 bytesDatabase mounted.Database opened.

1.5 物理standby切换为primary

standby>alter database commit to switchover to primary;alter database commit to switchover to primary*ERROR at line 1:ORA-16139: media recovery requiredstandby>alter database recover managed standby database disconnect from session;Database altered.standby>alter database commit to switchover to primary;Database altered.

1.6 重启新primary

standby> alter database open;Database altered.

1.7 新physical standby启动实时日志应用

Primary> alter database recover managed standby database using current logfile disconnect from session;

2.failover操作

模拟主库挂掉

Primary> shutdown abort;ORACLE instance shut down.

2.1 检查归档文件是否连续

查询待转换standby 数据库的V$ARCHIVE_GAP 视图，确认归档文件是否连接

StandBy>  SELECT THREAD#, LOW_SEQUENCE#, HIGH_SEQUENCE# FROM V$ARCHIVE_GAP; no rows selected

如果有，则拷贝过来;

手工的注册这些日志：

StandBy> ALTER DATABASE REGISTER LOGFILE '路径';

2.2 启动failover,备库切换主库操作。

StandBy> alter database recover managed standby database finish force;Database altered.StandBy> alter database commit to switchover to primary;Database altered.StandBy> alter database open;Database altered.