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Oracle Data Guard Linux 平台 Physical Standby 搭建实例

2011-09-28 12:58 429 查看
Data Guard 环境:

操作系统: redhat 4.7

Primary数据库:

IP地址:10.85.10.1。

数据库SID:orcl

DB_UNIQUE_NAME:orcl_pd



Standby数据库:

IP地址:10.85.10.2

数据库SID:orcl。

DB_UNIQUE_NAME:orcl_st







一. Primary 端的配置



1. 主库设置为force logging 模式

SQL> alter database force logging;



2. 主库设为归档模式

SQL> archive log list;

SQL> shutdown immediate

SQL> startup mount

SQL> alter database archivelog;

SQL> archive log list;



3. 添加redo log file

添加一个新的Standby Redologs组(注意组号不要与当前存在的Online Redologs组重复),并为该组指定一个成员:

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 4 ('/u01/app/oracle/oradata/orcl/redo04.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 5 ('/u01/app/oracle/oradata/orcl/redo05.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 6 ('/u01/app/oracle/oradata/orcl/redo06.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 7 ('/u01/app/oracle/oradata/orcl/redo07.log') size 50M;



4. 创建备库的密码文件和控制文件

SQL> alter database create standby controlfile as '/u01/control01.ctl';

-- 说明: 判断一个数据库是Primary还是Standby,就是通过控制文件来判断的。

[oracle@localhost dbs]$ orapwd file=/u01/app/oracle/product/10.2.0/db_1/dbs/orapworcl password=admin

如果已经存在,就不用创建了。 缺省情况下,win下口令文件的格式是pwdsid.ora,unix下的格式是orapwSID(大小写敏感)



5. 修改初始化参数文件

SQL> create pfile='/u01/initorcl.ora' from spfile;



在initorcl.ora 添加如下内容:

*.DB_UNIQUE_NAME='orcl_pd'

*.log_archive_dest_1='location=/u01/archive'

*.log_archive_dest_2='SERVICE=orcl_st'

*.LOG_ARCHIVE_DEST_STATE_1=ENABLE

*.LOG_ARCHIVE_DEST_STATE_2=ENABLE

*.standby_file_management='AUTO'

*.standby_archive_dest='/u01/archive'

*.FAL_SERVER='orcl_st'

*.FAL_CLIENT='orcl_pd'





如果主库和备库的数据文件位置不同,还需要加如下2个参数:

*.log_file_name_convert='/u02/oradata/orcl/','/u03/oradata/orcl/'

*.db_file_name_convert='/u02/oradata/orcl/','/u03/oradata/orcl/'





-- 注意:orcl_st,orcl_pd 是在tnsnames文件中配置的



用'/u01/initorcl.ora' 这个pfile 启动数据库,并生成spfile。

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup pfile='/u01/initorcl.ora';

ORACLE instance started.

Total System Global Area 167772160 bytes

Fixed Size 1218316 bytes

Variable Size 79694068 bytes

Database Buffers 83886080 bytes

Redo Buffers 2973696 bytes

Database mounted.

Database opened.

SQL> create spfile from pfile='/u01/initorcl.ora';

File created.



6. 修改listener.ora 和tnsnames.ora 文件



Listener.ora 文件:



SID_LIST_LISTENER =

(SID_LIST =

(SID_DESC =

(SID_NAME = PLSExtProc)

(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)

(PROGRAM = extproc)

)

(SID_DESC =

(GLOBAL_DBNAME = orcl)

(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)

(SID_NAME = orcl)

)

)



LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521))

(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))

)

)







注意:SID_LIST_LISTENER 配置的是静态注册,如果没有该参数,而且Data Guard 启动顺序又不正确,那么在主库可能会报 PING[ARC1]: Heartbeat failed to connect to standby 'orcl_st'. Error is 12514. 错误,导致归档无法完成。



Oracle Listener 动态注册 与 静态注册

/article/1673073.html







Tnsnames.ora 文件

ORCL_ST =

(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = TCP)(HOST = 10.85.10.2)(PORT = 1521))

)

(CONNECT_DATA =

(SERVER = DEDICATED)

(SERVICE_NAME = orcl)

)

)



ORCL_PD =

(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = TCP)(HOST = 10.85.10.1)(PORT = 1521))

)

(CONNECT_DATA =

(SERVER = DEDICATED)

(SERVICE_NAME = orcl)

)

)











二. Standby 端配置



1. 创建备库存放数据文件和后台跟踪目录, 这个目录可以和主库相同, 如果不同,就需要在主库的初始化文件中进行转换。

如:

*.log_file_name_convert='/u02/oradata/orcl/','/u03/oradata/orcl/'

*.db_file_name_convert='/u02/oradata/orcl/','/u03/oradata/orcl/'



$ORACLE_BASE/ORADATA/ORCL

$ORACLE_BASE/admin/orcl

$ORACLE_BASE/admin/orcl/adump

$ORACLE_BASE/admin/orcl/bdump

$ORACLE_BASE/admin/orcl/cdump

$ORACLE_BASE/admin/orcl/dpdump

$ORACLE_BASE/admin/orcl/pfile

$ORACLE_BASE/admin/orcl/udump

$ORACLE_BASE/admin/orcl/



2. 将主库的密码文件,控制文件,数据文件,参数文件,日志文件copy到备库。

说明一点,这个控制文件是我们自己创建的standby 控制文件。将copy过来的控制文件再复制三份就可以了。 主备的控制文件是不一样的。 这里除了采用直接copy 文件之外,还可以采用Rman 恢复来做。 直接copy 需要停数据库,如果采用RMAN 的话,就不需要停机了。

[oracle@localhost orcl]$ pwd

/u01/app/oracle/oradata/orcl

[oracle@localhost orcl]$ ls

control01.ctl redo01.log redo04.log redo07.log temp01.dbf

control02.ctl redo02.log redo05.log sysaux01.dbf undotbs01.dbf

control03.ctl redo03.log redo06.log system01.dbf users01.dbf

[oracle@localhost orcl]$ scp *.dbf 10.85.10.2://u01/app/oracle/oradata/orcl

[oracle@localhost u01]$ scp *.ctl 10.85.10.2://u01/app/oracle/oradata/orcl

[oracle@localhost u01]$ scp *.log 10.85.10.2://u01/app/oracle/oradata/orcl

[oracle@localhost u01]$ scp initorcl.ora 10.85.10.2://u01/app/oracle/product/10.2.0/db_1/dbs

[oracle@localhost dbs]$ scp orapworcl 10.85.10.2://u01/app/oracle/product/10.2.0/db_1/dbs



3. 修改初始化参数文件

修改之后如下:

*.DB_UNIQUE_NAME='orcl_st'

*.log_archive_dest_1='location=/u01/archive'

*.log_archive_dest_2='SERVICE=orcl_pd'

*.LOG_ARCHIVE_DEST_STATE_1=ENABLE

*.LOG_ARCHIVE_DEST_STATE_2=ENABLE

*.FAL_SERVER='orcl_st'

*.FAL_CLIENT='orcl_pd'

*.standby_file_management='AUTO'

*.standby_archive_dest='/u01/archive'



4. 修改listener.ora 和 tnsnames.ora 文件,如果不存在,就从主库上copy 过去。



5. 在备库添加redo log file

如果主库没有添加redo log file,可以先用copy 过来的初始化文件将数据库启动到mount 状态。在创建个spfile,最后添加redo log。

SQL> startup mount pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/initorcl.ora'

ORACLE instance started.

SQL> create spfile from pfile='/u01/app/oracle/product/10.2.0/db_1/dbs/initorcl.ora';



添加一个新的Standby Redologs组(注意组号不要与当前存在的Online Redologs组重复),并为该组指定一个成员:

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 4 ('/u01/app/oracle/oradata/orcl/redo04.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 5 ('/u01/app/oracle/oradata/orcl/redo05.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 6 ('/u01/app/oracle/oradata/orcl/redo06.log') size 50M;

SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 7 ('/u01/app/oracle/oradata/orcl/redo07.log') size 50M;



提示,由于从Primary数据库复制文件时并没有复制Online Redologs,因此物理Standby数据库在第一次启动REDO应用时,会在Alert文件中报Online Redo Logfile文件不存在,没有关系,物理Standby会自动重建这批文件,同时你也不用担心会丢失数据,Online Redologs中的数据会以归档文件的形式从Primary端接收。





至此,Data Guard 的操作已经完成,下面来开始验证。





注意Data Guard 启动顺序:

启动顺序:先standby ,后primary;


关闭顺序:先primary 后standby;





在备库将实例启动到mount 状态:

SQL> startup nomount;

SQL>alter database mount standby database ;

SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

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



在备库启动监听:

$lsnrctl start



在主库启动实例:

SQL> startup;



在主库启动监听:

$lsnrctl start



在主库验证归档目录是否有效:

SQL> SELECT STATUS,DESTINATION, ERROR FROM V$ARCHIVE_DEST;

如果有错误,要排查原因。



SQL> alter system switch logfile;



SQL> select max(sequence#) from v$archived_log;



MAX(SEQUENCE#)

--------------

70



主备查询结果一致,Data Guard 搭建结束。







注意:如果在主库执行 alter database clear unarchived logfile或alter database open resetlogs , 则dataguard要重建









三. 一些其他操作



1. 首先查看当前的保护模式 ---primary数据库操作

SQL> select protection_mode,protection_level from v$database;

PROTECTION_MODE PROTECTION_LEVEL

-------------------- --------------------

MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE



2. 设置新的数据保护模式并重启数据库 --primary数据库操作



当保护模式更改顺序:

maximize protection ---> maximize availability ----> maximize performance

当在把dataguard的保护级别按这上面的顺序减低的时候, 不需要primary库在mount状态,否则primary 必须在mount 状态。



如:

SQL> alter database set standby database to maximize availability;

alter database set standby database to maximize availability

*

ERROR at line 1:

ORA-01126: database must be mounted in this instance and not open in any

instance



SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount;

ORACLE instance started.



Total System Global Area 167772160 bytes

Fixed Size 1218316 bytes

Variable Size 79694068 bytes

Database Buffers 83886080 bytes

Redo Buffers 2973696 bytes

Database mounted.

SQL> alter database set standby database to maximize availability;

Database altered.

SQL> alter database open;

alter database open

*

ERROR at line 1:

ORA-03113: end-of-file on communication channel



报错了,这是因为最大可用性需要先修改日志传送方式为lgwr同步方式,否则,数据库是无法open.



Maximum protection/***AILABILITY模式必须满足以下条件

Redo Archival Process: LGWR

Network Tranmission mode: SYNC

Disk Write Option: AFFIRM

Standby Redo Logs: Yes

standby database type: Physical Only



SQL> alter system set log_archive_dest_2='service=orcl_st lgwr sync AFFIRM';

System altered.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount;

ORACLE instance started.

Total System Global Area 167772160 bytes

Fixed Size 1218316 bytes

Variable Size 79694068 bytes

Database Buffers 83886080 bytes

Redo Buffers 2973696 bytes

Database mounted.

SQL> alter database set standby database to maximize availability;

Database altered.

SQL> alter database open;

Database altered.

SQL> select protection_mode,protection_level from v$database;

PROTECTION_MODE PROTECTION_LEVEL

-------------------- --------------------

MAXIMUM ***AILABILITY MAXIMUM ***AILABILITY





alter database set standby database to maximize performance;

提示:maximize后可跟{PROTECTION | ***AILABILITY | PERFORMANCE},分别对应最大保护,最高可用性及最高性能。



在最大保护模式下,直接关闭备库是不行的,如果在备库上关闭数据库,会有如下提示:

SQL> shutdown immediate

ORA-01154: database busy. Open, close, mount, and dismount not allowed now

SQL>

在最大保护模式下,备库是不允许关闭的,此时首先关闭主库,然后备库就可以顺利关闭了。

注意: 主库的保护模式修改之后,备库的模式也会改变,和主库保持一致。





3. 查看日志归档情况



主库进行日志切换:

SQL>Alter system switch logfile;



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)可以在备库坐如下操作:

alter database recover managed standby database cancel;

alter database recover managed standby database disconnect from session;











四. 主备库切换





4.1 Switchover



一般SWITCHOVER切换都是计划中的切换,特点是在切换后,不会丢失任何的数据,而且这个过程是可逆的,整个DATA GUARD环境不会被破坏,原来DATA GUARD环境中的所有物理和逻辑STANDBY都可以继续工作。



在进行DATA GUARD的物理STANDBY切换前需要注意:

1)确认主库和从库间网络连接通畅;

2)确认没有活动的会话连接在数据库中;

3)PRIMARY数据库处于打开的状态,STANDBY数据库处于MOUNT状态;

4)确保STANDBY数据库处于ARCHIVELOG模式;

5)如果设置了REDO应用的延迟,那么将这个设置去掉;

6)确保配置了主库和从库的初始化参数,使得切换完成后,DATA GUARD机制可以顺利的运行。 ­



主库:

1. 查看switchover 状态

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;

SWITCHOVER_STATUS

--------------------

TO STANDBY



附: A:switchover_status出现session active/not allowed



当出现session active的时候表示还有活动的session,则运行

Alter database commit to switchover to physical standby with session shutdown;

当出现not allowed时,在官方文档说转换会不成功,但是我测试的时候成功了。



B.ora- 01153: an incompatible media recovery is active

运行下面代码

Alter database recover managed standby database finish;

或者Alter database recover managed standby database finish force;

Alter database recover managed standby database disconnect from session;



2 切换成备库

SQL>Alter database commit to switchover to physical standby with session shutdown;

或者

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY;

Database altered.



3 启动到mount和应用日志状态

SQL> SHUTDOWN IMMEDIATE

SQL> startup nomount;

SQL> alter database mount standby database;

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;



4. 查看数据库模式

SQL>select dest_name,status,database_mode,recovery_mode,protection_mode from v$archive_dest_status;

SQL>select status,database_mode from v$archive_dest_status;





备库:

1.查看switchover状态

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;

TO PRIMARY

附:若不是用此语句切换:ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY with session shutdown



补充:若出现:ORA-16139: media recovery required

是因为没有执行:alter database recover managed standby database disconnect from session;



2. 切换成主库

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;

Database altered.

SQL> shutdown immediate;

SQL> startup;

SQL> alter system switch logfile;



3. 查看数据库模式

SQL>select dest_name,status,database_mode,recovery_mode,protection_mode from v$archive_dest_status;

SQL>select status,database_mode from v$archive_dest_status;



验证同步:

SQL> select max(sequence#) from v$archived_log;

MAX(SEQUENCE#)

--------------

78







4.2. Failovers:



FAILOVER切换一般是PRIMARY数据库发生故障后的切换,这种情况是STANDBY数据库发挥其作用的情况。这种切换发生后,可能会造成数据的丢失。而且这个过程不是可逆的,DATA GUARD环境会被破坏。



由于PRIMARY数据库已经无法启动,所以FAILOVER切换所需的条件并不多,只要检查STANDBY是否运行在最大保护模式下,如果是的话,需要将其置为最大性能模式,否则切换到PRIMARY角色也无法启动。





1. 查看是否有日志GAP,没有应用的日志:



SQL> SELECT UNIQUE THREAD#, MAX(SEQUENCE#) OVER(PARTITION BY THREAD#) LAST FROM V$ARCHIVED_LOG;

  SQL> SELECT THREAD#, LOW_SEQUENCE#, HIGH_SEQUENCE# FROM V$ARCHIVE_GAP;



  如果有,则拷贝过来并且注册

SQL> ALTER DATABASE REGISTER PHYSICAL LOGFILE '路径';

重复查看直到没有应用的日志:



2. 然后停止应用归档:

  SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

  Database altered.



3. 下面将STANDBY数据库切换为PRIMARY数据库: ­

  SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH;

或 SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH FORCE;

  Database altered.



  SQL> SELECT DATABASE_ROLE FROM V$DATABASE;

  DATABASE_ROLE

  ----------------

  PHYSICAL STANDBY



  SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;

  Database altered.



SQL> ALTER DATABASE OPEN; 或者 shutdown immediate+startup

  Database altered.



  检查数据库是否已经切换成功:



  SQL> SELECT DATABASE_ROLE FROM V$DATABASE;

  DATABASE_ROLE

  ----------------

  PRIMARY



至此,FAILOVER切换完成。这个时候应该马上对新的PRIMARY数据库进行备份。
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