1、部署环境:
Oracle 10G DataGuard
主库:HOSTNAME: primary IP: 139.0.0.31 SID=ccpbs
备库:HOSTNAME: standby IP: 139.0.0.32 SID=ccpbs
oracle version:10.2.0.1
OS platform : OEL5.4
VMware 运行 主备虚拟机
Data Guard 默认是 maximize performance, 可以用以下语句来进行模式间的切换。
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE {PROTECTION |
AVAILABILITY | PERFORMANCE};
修改主数据库保护模式需要重启数据库才能生效。
select protection_mode,protection_level from v$database;
2、准备工作
1、在主备机分别安装 OEL5.4 操作系统分别设置 HOSTNAME 为 “odd”、
“even”;
2、在主备机上分别安装 oracle 10gR2 数据库,安装时注意选择“高级”,只安装“数据库软件;”
3、只在主机上用 dbca 新建数据库实例,选择默认选项,SID 名和 SERVICE 名设定为
“ccpbs”;
参数规划:
数据库 | db_name | sid | instance_name | service_names | db_unique_name | fal_server | fal_client |
主库 | ccpbs | ccpbs | ccpbs | pri | pri | stdby | pri |
备库 | ccpbs | ccpbs | ccpbs | Stdby | stdby | pri | stdby |
3、正式开始配置
3.1 设置主数据库为 force logging 模式
$ sqlplus / nolog;
SQL> conn / as sysdba;
SQL> alter database force logging;

3.2 设置主数据库为归档模式
SQL> archive log list
SQL> shutdown immediate
SQL> startup mount
SQL> alter database archivelog;
SQL> archive log list
3.3 数据文件拷贝
数据文件的拷贝可以分为两种模式:rman 和文件的直接拷贝,由于我们的系统可以停机,所以会采用第二种方式。注意不用拷贝 redo 文件,备用机在启动的时候会自动的创建 redo 文件。控制文件也不用拷贝。
3.31、拷贝主库的数据文件到备库中
SQL> SELECT NAME FROM v$datafile;
SQL> select name from v$tempfile;
把主库的以上数据文件拷贝到备库上同样目录
3.32、创建从库的控制文件
在主库上为从库创建控制文件(不要和主库控制文件重名),然后拷贝到从库
/home/oracle/oracle10g/oradata/ccpbs/ 目录下。(记住这个目录,在下面从库的 spfile 配置中要用到)。
SQL> ALTER DATABASE CREATE STANDBY CONTROLFILE AS '/HOME/ORACLE/STANDBY.CTL';
3.33 从库创建 admin 目录
将主库的 /home/oracle/oracle10g/admin/ccpbs 目录及文件夹拷贝到从库的相同目录。
3.34 在从库上创建密码文件
缺省情况下, linux 下的格式是 orapwSID(大小写敏感)
在$ORACLE_HOME/dbs目录下,创建密码文件:
orapwd file=orapwccpbs password=oracle
建议直接拷贝主库该位置的文件到备库对应位置。
3.35 创建从库 flash_recovery_area 目录
在 /home/oracle/oracle10g目录中创建 flash_recover_area 目录,该目录参数在从库中有设定,为*.db_recovery_file_dest 项的值,如果没有会出错。
3.4修改 spfile 文件
说明:我们在这里需要先根据 spfile生成 pfile 文件,然后修改好对应的参数值,再依据 pfile 生成 spfile 文件。
3.41、创建 pfile 文件
在主库上创建 pfile 文件
SQL> CREATE PFILE FROM SPFILE;
生成的pfile文件,默认格式为 initSID.ora,此处为initccpbs.ora
文件路径为/home/oracle/oracle10g/product/10.2.0/db_1/dbs
将主库生成的pfile文件,拷贝到从库相同目录下。
修改主库的 initccpbs.ora 文件如下,红色部分为需要新加入的内容,蓝色部分是特别需要注意的部分:
--------------------------initccpbs.ora----------------------------------------------------------------
ccpbs.__db_cache_size=188743680
ccpbs.__java_pool_size=4194304
ccpbs.__large_pool_size=4194304
ccpbs.__shared_pool_size=83886080
ccpbs.__streams_pool_size=0
*.audit_file_dest='/home/oracle/oracle10g/admin/ccpbs/adump'
*.background_dump_dest='/home/oracle/oracle10g/admin/ccpbs/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/home/oracle/oracle10g/oradata/ccpbs/control01.ctl','/home/oracle/oracle10g/oradata/ccpbs/control02.ctl','/home/oracle/oracle10g/oradata/ccpbs/control03.ctl'
*.core_dump_dest='/home/oracle/oracle10g/admin/ccpbs/cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='ccpbs'
*.db_recovery_file_dest='/home/oracle/oracle10g/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=ccpbsXDB)'
*.job_queue_processes=10
*.nls_language='SIMPLIFIED CHINESE'
*.nls_territory='CHINA'
*.open_cursors=300
*.pga_aggregate_target=94371840
*.processes=300
*.remote_login_passwordfile='EXCLUSIVE'
*.sessions=335
*.sga_target=285212672
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/home/oracle/oracle10g/admin/ccpbs/udump'
*.db_unique_name='pri'
*.fal_server='stdby'
*.fal_client='pri'
*.LOG_ARCHIVE_CONFIG='DG_CONFIG=(pri,stdby)'
*.log_archive_dest_1='LOCATION=/home/oracle/arch1/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=pri'
*.LOG_ARCHIVE_DEST_2='SERVICE=stdby LGWR ASYNC=40960 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=stdby'
*.LOG_ARCHIVE_DEST_STATE_1='ENABLE'
*.log_archive_dest_state_2='ENABLE'
*.standby_archive_dest='/home/oracle/arch1/'
*.standby_file_management='AUTO'
------------------------------------------------------------------------------------------
修改从库的 initccpbs.ora文件加入如下:
----------------------------------------initccpbs.ora--------------------------------------------------
ccpbs.__db_cache_size=188743680
ccpbs.__java_pool_size=4194304
ccpbs.__large_pool_size=4194304
ccpbs.__shared_pool_size=83886080
ccpbs.__streams_pool_size=0
*.audit_file_dest='/home/oracle/oracle10g/admin/ccpbs/adump'
*.background_dump_dest='/home/oracle/oracle10g/admin/ccpbs/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/home/oracle/oracle10g/oradata/ccpbs/stdby.ctl'
*.core_dump_dest='/home/oracle/oracle10g/admin/ccpbs/cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='ccpbs'
*.db_recovery_file_dest='/home/oracle/oracle10g/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=ccpbsXDB)'
*.job_queue_processes=10
*.nls_language='SIMPLIFIED CHINESE'
*.nls_territory='CHINA'
*.open_cursors=300
*.pga_aggregate_target=94371840
*.processes=300
*.remote_login_passwordfile='EXCLUSIVE'
*.sessions=335
*.sga_target=285212672
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/home/oracle/oracle10g/admin/ccpbs/udump'
*.db_unique_name='stdby'
*.fal_server='pri'
*.fal_client='stdby'
*.LOG_ARCHIVE_CONFIG='DG_CONFIG=(pri,stdby)'
*.log_archive_dest_1='LOCATION=/home/oracle/arch1/ VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=stdby'
*.LOG_ARCHIVE_DEST_2='SERVICE=pri LGWR ASYNC=40960 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=pri'
*.LOG_ARCHIVE_DEST_STATE_1='ENABLE'
*.log_archive_dest_state_2='ENABLE'
*.log_file_name_convert='/home/oracle/arch1','/home/oracle/arch1'
*.standby_archive_dest='/home/oracle/arch1/'
*.standby_file_management='AUTO' ------------------------------------------------------------------------------------------
3.42、创建 spfile 文件
从库:备份原spfile文件,将修改完成的 pfile 重新生成spfile文件
SQL> CREATE SPFILE FROM PFILE;
从库:
SQL>CREATE SPFILE FROM PFILE;
启动从库到mount状态
SQL>startup mount;
3.5创建备机redo日志
因为我们使用 LGWR 所以我们要创建 standby redo 日志。
一定要日志注意的大小,要和主库一样。
万一加错了日志可以使用下面的语句进行删除。
ALTER DATABASE DROP LOGFILE GROUP 8;
先查看日志文件位置:
SQL>select * from v$logfile;
再添加:
SQL> alter database add standby logfile group 4 /home/oracle/oracle10g/oradata/ccpbs/redo04.log size 50m;
SQL> alter database add standby logfile group 5 /home/oracle/oracle10g/oradata/ccpbs/redo05.log size 50m;
SQL> alter database add standby logfile group 6 /home/oracle/oracle10g/oradata/ccpbs/redo06.log size 50m;
SQL> alter database add standby logfile group 7 /home/oracle/oracle10g/oradata/ccpbs/redo07.log size 50m;
3.6配置网络,修改 listener.ora ,tnsnames.ora
3.61 配置
先在主从库上分别用 netca 命令配置监听和本地服务名,再分别编辑主、从库的 listener.ora,tnsnames.ora,参数以下
主库的 listener.ora 文件如下:
######################################################################################################
# listener.ora Network Configuration File: /home/oracle/oracle10g/product/10.2.0/db_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /home/oracle/oracle10g/product/10.2.0/db_1)
(PROGRAM = extproc)
)
(SID_DESC=
(GLOBAL_DBNAME=ccpbs)
(ORACLE_HOME=/home/oracle/oracle10g/product/10.2.0/db_1)
(SID_NAME=ccpbs)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = odd)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
) ######################################################################################################
主库的 tnsnames.ora 文件如下:
######################################################################################################
# tnsnames.ora Network Configuration File: /home/oracle/oracle10g/product/10.2.0/db_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
CCPBS =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 139.0.0.31)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ccpbs)
)
)
pri =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 139.0.0.31)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ccpbs)
)
)
stdby =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 139.0.0.32)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ccpbs)
)
)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
) ######################################################################################################
在上面配置完成之后,需要在主、备机上重启监听服务
$ Lsnrctl stop
$ lsnrctl start
可以使用 lsnrctl status
命令查看监听器状态
3.62 测试网络配置
如果配置成功,在主机上测试
$ tnsping pri
$ tnsping stdby 也能得到相似结果
$ sqlplus sys/oracle@pri as sysdba;
$ sqlplus sys/oracle@stdby as sysdba; 也能得到相似结果
在备机上执行上面四条指令也能得到正确的结果,则说明网络配置成功。
3.7启动主备服务
上面配置完成后先将主、备数据库关闭
SQL> shutdown immediate;
然后分别在主、备机上重启监听器
CMD> lsnrctl stop
CMD> lsnrctl start
然后依次打开主库和备库
3.71 主库
SQL> CONN / AS SYSDBA
SQL> STARTUP
3.72 备库
SQL> STARTUP MOUNT;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT
FROM SESSION;
到次为止,最关键的时刻来了,我们要测试看是否配置成功,如果成功的话在主机上的归档
就能顺利传到
3.73 测试归档
1. 测试主库产生的归档日志是否能正常传送到归档日志
在主机上
SQL>archive log list;
SQL>alter system archive log current;
SQL>archive log list;
主库进行日志切换:
SQL>Alter system switch logfile;
然后分别查看主库和备库的 /home/oracle/arch1 目录下是否产生了同样的归档日志
文件。
select max(sequence#) from v$archived_log;
select max(sequence#) from v$log_history;
select group#,sequence#,archived,status from v$log;
select name,sequence#,applied from v$archived_log;
select sequence#,applied from v$archived_log;
若不同步,
1. 看 log 日志, archive 是否有丢失
2. 可以在备库做如下操作:
alter database recover managed standby database cancel;
alter database recover managed standby database disconnect from session;
4、日常维护
4.1 正确打开主库和备库
主库:
SQL> CONN / AS SYSDBA
SQL> STARTUP
备库:
SQL> STARTUP MOUNT;
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
4.2 正确关闭顺序
备库:
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
SQL>SHUTDOWN IMMEDIATE;
主库
SQL>SHUTDOWN IMMEDIATE;
4.3 备库Read-only模式打开
当前主库正常 OPEN 状态、备库处于日志传送状态.
1 在备库停止日志传送
SQL> recover managed standby database cancel;
2 备库 Read-only 模式打开
SQL> alter database open read only;
3 备库回到日志传送模式
SQL> recover managed standby database disconnect from session;
SQL> select status from v$instance;
4.4 日志传输状态监控
1 主库察看当前日志状况
SQL> select sequence#,status from v$log;
2 备库察看 RFS(Remote File Service)接收日志情况和 MRP 应用日志同步主库
情况
SQL> SELECT PROCESS, STATUS, THREAD#, SEQUENCE#, BLOCK#, BLOCKS
FROM V$MANAGED_STANDBY;
3 察看备库是否和主库同步
SQL> SELECT ARCHIVED_THREAD#, ARCHIVED_SEQ#, APPLIED_THREAD#,
APPLIED_SEQ# FROM V$ARCHIVE_DEST_STATUS;
4 察看备库已经归档的 redo
SQL> SELECT REGISTRAR, CREATOR, THREAD#, SEQUENCE#, FIRST_CHANGE#,
NEXT_CHANGE# FROM V$ARCHIVED_LOG;
5 察看备库已经应用的 redo
SQL> SELECT THREAD#, SEQUENCE#, FIRST_CHANGE#, NEXT_CHANGE#
FROM V$LOG_HISTORY;
6 察看备库接收,应用 redo 数据过程.
SQL> SELECT MESSAGE FROM V$DATAGUARD_STATUS;
4.5 备库归档目录维护
1 找到备库归档目录
SQL> show parameter log_archive_dest_1
2 维护策略
每周 2,4,7 删除已经应用的归档文件
5、主库正常切换
5.1人工干预正常切换
1 在主库端检验数据库可切换状态
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS:TO STANDBY 表示可以正常切换.
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE,表示当前有会话处于 ACTIVE
状态
2 开始主库正常切换
如果 SWITCHOVER_STATUS 的值为 TO STANDBY 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY;
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;
成功运行这个命令后,主库被修改为备库
3 重启先前的主库
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP MOUNT;
4 在从库验证可切换状态
主库未执行切换命令时的从库可切换状态如下:
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
-----------------
NOT ALLOWED
主库执行切换命令后的从库可切换状态如下:
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
-----------------
TO_PRIMARY
1 row selected
5 将目标备库转换为主库
如果 SWITCHOVER_STATUS 的值为 TO STANDBY 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
成功运行这个命令后,备库被修改为主库
6 重启目标备库
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
7 先前主库启动日志传送进程
SQL> alter database recover managed standby database disconnect;
总结: 这样主库的一次正常切换完成.切换后的状态,原先的主库变为备库,原先的备库变为主库.
6、主库灾难切换
6.1 人工干预主库灾难切换
从库:
SQL>alter database recover managed standby database cancel;
SQL>shutdown immediate
SQL>startup mount
SQL>ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE;
SQL>alter database recover managed standby database finish;
-- switch
SQL>alter database commit to switchover to primary with session shutdown;
-- open
SQL>shutdown immediate
SQL>startup
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 139.0.0.32)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ccpbs)
)
)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
) ######################################################################################################
在上面配置完成之后,需要在主、备机上重启监听服务
$ Lsnrctl stop
$ lsnrctl start
可以使用 lsnrctl status
命令查看监听器状态
3.62 测试网络配置
如果配置成功,在主机上测试
$ tnsping pri
$ tnsping stdby 也能得到相似结果
$ sqlplus sys/oracle@pri as sysdba;
$ sqlplus sys/oracle@stdby as sysdba; 也能得到相似结果
在备机上执行上面四条指令也能得到正确的结果,则说明网络配置成功。
3.7启动主备服务
上面配置完成后先将主、备数据库关闭
SQL> shutdown immediate;
然后分别在主、备机上重启监听器
CMD> lsnrctl stop
CMD> lsnrctl start
然后依次打开主库和备库
3.71 主库
SQL> CONN / AS SYSDBA
SQL> STARTUP
3.72 备库
SQL> STARTUP MOUNT;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT
FROM SESSION;
到次为止,最关键的时刻来了,我们要测试看是否配置成功,如果成功的话在主机上的归档
就能顺利传到
3.73 测试归档
1. 测试主库产生的归档日志是否能正常传送到归档日志
在主机上
SQL>archive log list;
SQL>alter system archive log current;
SQL>archive log list;
主库进行日志切换:
SQL>Alter system switch logfile;
然后分别查看主库和备库的 /home/oracle/arch1 目录下是否产生了同样的归档日志
文件。
select max(sequence#) from v$archived_log;
select max(sequence#) from v$log_history;
select group#,sequence#,archived,status from v$log;
select name,sequence#,applied from v$archived_log;
select sequence#,applied from v$archived_log;
若不同步,
1. 看 log 日志, archive 是否有丢失
2. 可以在备库做如下操作:
alter database recover managed standby database cancel;
alter database recover managed standby database disconnect from session;
4、日常维护
4.1 正确打开主库和备库
主库:
SQL> CONN / AS SYSDBA
SQL> STARTUP
备库:
SQL> STARTUP MOUNT;
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
4.2 正确关闭顺序
备库:
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
SQL>SHUTDOWN IMMEDIATE;
主库
SQL>SHUTDOWN IMMEDIATE;
4.3 备库Read-only模式打开
当前主库正常 OPEN 状态、备库处于日志传送状态.
1 在备库停止日志传送
SQL> recover managed standby database cancel;
2 备库 Read-only 模式打开
SQL> alter database open read only;
3 备库回到日志传送模式
SQL> recover managed standby database disconnect from session;
SQL> select status from v$instance;
4.4 日志传输状态监控
1 主库察看当前日志状况
SQL> select sequence#,status from v$log;
2 备库察看 RFS(Remote File Service)接收日志情况和 MRP 应用日志同步主库
情况
SQL> SELECT PROCESS, STATUS, THREAD#, SEQUENCE#, BLOCK#, BLOCKS
FROM V$MANAGED_STANDBY;
3 察看备库是否和主库同步
SQL> SELECT ARCHIVED_THREAD#, ARCHIVED_SEQ#, APPLIED_THREAD#,
APPLIED_SEQ# FROM V$ARCHIVE_DEST_STATUS;
4 察看备库已经归档的 redo
SQL> SELECT REGISTRAR, CREATOR, THREAD#, SEQUENCE#, FIRST_CHANGE#,
NEXT_CHANGE# FROM V$ARCHIVED_LOG;
5 察看备库已经应用的 redo
SQL> SELECT THREAD#, SEQUENCE#, FIRST_CHANGE#, NEXT_CHANGE#
FROM V$LOG_HISTORY;
6 察看备库接收,应用 redo 数据过程.
SQL> SELECT MESSAGE FROM V$DATAGUARD_STATUS;
4.5 备库归档目录维护
1 找到备库归档目录
SQL> show parameter log_archive_dest_1
2 维护策略
每周 2,4,7 删除已经应用的归档文件
5、主库正常切换
5.1人工干预正常切换
1 在主库端检验数据库可切换状态
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS:TO STANDBY 表示可以正常切换.
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE,表示当前有会话处于 ACTIVE
状态
2 开始主库正常切换
如果 SWITCHOVER_STATUS 的值为 TO STANDBY 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY;
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;
成功运行这个命令后,主库被修改为备库
3 重启先前的主库
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP MOUNT;
4 在从库验证可切换状态
主库未执行切换命令时的从库可切换状态如下:
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
-----------------
NOT ALLOWED
主库执行切换命令后的从库可切换状态如下:
SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
-----------------
TO_PRIMARY
1 row selected
5 将目标备库转换为主库
如果 SWITCHOVER_STATUS 的值为 TO STANDBY 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
如果 SWITCHOVER_STATUS 的值为 SESSIONS ACTIVE 则:
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
成功运行这个命令后,备库被修改为主库
6 重启目标备库
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
7 先前主库启动日志传送进程
SQL> alter database recover managed standby database disconnect;
总结: 这样主库的一次正常切换完成.切换后的状态,原先的主库变为备库,原先的备库变为主库.
5.2 通过运行脚本实现主库正常切换
6、主库灾难切换
6.1 人工干预主库灾难切换
从库:
SQL>alter database recover managed standby database cancel;
SQL>shutdown immediate
SQL>startup mount
SQL>ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE;
SQL>alter database recover managed standby database finish;
-- switch
SQL>alter database commit to switchover to primary with session shutdown;
-- open
SQL>shutdown immediate
SQL>startup
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