Dataguard采用最大性能模式.
第一部分 日常维护
一 正确打开主库和备库
1
主库:
SQL> startup mount
SQL> alter database archivelog;
SQL> alter database open;
2
备库:
SQL> startup mount
SQL>
alter database recover managed standby database disconnect from
session;
OR =>> alter database recover managed standby database using current logfile disconnect from session;
二 正确关闭顺序
1
备库:
SQL> alter database recover managed standby database cancel;
SQL>
shutdown immediate;
2
主库
SQL>shutdown immediate;
三 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;
Media recovery
complete.
SQL> select status from v$instance;
STATUS
------------
MOUNTED
四 日志传送状态监控
1
主库察看当前日志状况
SQL>
select sequence#,status from v$log;
SEQUENCE#
STATUS
---------- ----------------
51 ACTIVE
52 CURRENT
50
INACTIVE
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$MANAGED_STANDBY;
PROCESS
STATUS THREAD# SEQUENCE# BLOCK# BLOCKS
--------- ------------ ----------
---------- ---------- ----------
ARCH CONNECTED 0 0 0 0
ARCH CONNECTED 0 0
0 0
RFS RECEIVING 0 0 0 0
MRP0 WAIT_FOR_LOG 1 52 0 0
RFS RECEIVING 0 0
0 0
可以看到备库MPR0正等待SEQUENCE#为52的redo.
3
察看备库是否和主库同步
SQL>
SELECT ARCHIVED_THREAD#, ARCHIVED_SEQ#, APPLIED_THREAD#, APPLIED_SEQ# FROM
V$ARCHIVE_DEST_STATUS;
ARCHIVED_THREAD#
ARCHIVED_SEQ# APPLIED_THREAD# APPLIED_SEQ#
---------------- -------------
--------------- ------------
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0
0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
1 51 1
50
可以看到备库已经将SEQUENCE#51的日志归档,已经将SEQUENCE#50的redo应用到备库.
由于已经将SEQUENCE#51的日志归档,所以SEQUENCE#51以前的数据不会丢失.
4
察看备库已经归档的redo
SQL>
select registrar, creator, thread#, sequence#, first_change#, next_change# from
v$archived_log;
REGISTR
CREATOR THREAD# SEQUENCE# FIRST_CHANGE# NEXT_CHANGE#
------- -------
---------- ---------- ------------- ------------
SRMN SRMN 1 37 572907
573346
RFS ARCH 1 38 573346 573538
RFS ARCH 1 39 573538 573623
RFS ARCH
1 40 573623 573627
RFS ARCH 1 41 573627 574326
RFS ARCH 1 42 574326
574480
RFS
ARCH 1 49 601476 601532
RFS ARCH 1 50 601532 606932
RFS ARCH 1 51 606932
607256
5
察看备库已经应用的redo
SQL>
select thread#, sequence#, first_change#, next_change# from
v$log_history;
THREAD#
SEQUENCE# FIRST_CHANGE# NEXT_CHANGE#
---------- ---------- -------------
------------
1 1 366852 368222
1 2 368222 369590
1 3 369590 371071
1
4 371071 372388
1 5 372388 376781
1 6 376781 397744
1 7 397744
407738
1 8 407738 413035
1 9 413035 413037
1
50 601532 606932
1 51 606932 607256
可以看到备库已经将SEQUENCE#为51的归档文件应用到备库.
6
察看备库接收,应用redo数据过程.
SQL>
select message from v$dataguard_status;
MESSAGE
--------------------------------------------------------------------------------
ARC0:
Archival started
ARC0: Becoming the 'no FAL' ARCH
ARC0: Becoming the 'no
SRL' ARCH
ARC1: Archival started
ARC1: Becoming the heartbeat ARCH
Redo
Shipping Client Connected as PUBLIC
-- Connected User is Valid
RFS[1]:
Assigned to RFS process 19740
RFS[1]: Identified database type as 'physical
standby'
Primary database is in MAXIMUM PERFORMANCE mode
Attempt to start
background Managed Standby Recovery process
MESSAGE
--------------------------------------------------------------------------------
MRP0:
Background Managed Standby Recovery process started
Managed Standby Recovery
not using Real Time Apply
Clearing online redo logfile 7
/oraguard/redo1/redo_7_1.log
Clearing online redo logfile 7 complete
Media
Recovery Waiting for thread 1 sequence 47
RFS[1]: No standby redo logfiles
created
Redo Shipping Client Connected as PUBLIC
-- Connected User is
Valid
RFS[2]: Assigned to RFS process 19746
RFS[2]: Identified database
type as 'physical standby'
Primary database is in MAXIMUM PERFORMANCE
mode
MESSAGE
--------------------------------------------------------------------------------
Committing
creation of archivelog '/arch/1_47_552308270.arc'
Media Recovery Log
/arch/1_47_552308270.arc
Media Recovery Waiting for thread 1 sequence
48
MRP0: Background Media Recovery cancelled with status 16037
MRP0:
Background Media Recovery process shutdown
Managed Standby Recovery
Canceled
Attempt to start background Managed Standby Recovery
process
MRP0: Background Managed Standby Recovery process started
Managed
Standby Recovery not using Real Time Apply
Media Recovery Waiting for thread
1 sequence 48
RFS[1]: No standby redo logfiles created
MESSAGE
--------------------------------------------------------------------------------
Committing
creation of archivelog '/arch/1_48_552308270.arc'
Media Recovery Log
/arch/1_48_552308270.arc
Media Recovery Waiting for thread 1 sequence
49
RFS[1]: No standby redo logfiles created
Committing creation of
archivelog '/arch/1_49_552308270.arc'
Media Recovery Log
/arch/1_49_552308270.arc
Media Recovery Waiting for thread 1 sequence
50
RFS[1]: No standby redo logfiles created
Committing creation of
archivelog '/arch/1_50_552308270.arc'
Media Recovery Log
/arch/1_50_552308270.arc
Media Recovery Waiting for thread 1 sequence
51
MESSAGE
--------------------------------------------------------------------------------
RFS[1]:
No standby redo logfiles created
Committing creation of archivelog
'/arch/1_51_552308270.arc'
Media Recovery Log
/arch/1_51_552308270.arc
Media Recovery Waiting for thread 1 sequence
52
可以看到RFS接收到sequence#为51的归档文件并存至备库归档目录/arch/1_51_552308270.arc.
Oracle自动应用文件/arch/1_51_552308270.arc进行备库与主库同步
Oracle继续等待主库sequence
52的归档文件
五 备库归档目录维护
1 找到备库归档目录
SQL>
show parameter log_archive_dest_1
NAME
TYPE
------------------------------------
--------------------------------
VALUE
------------------------------
log_archive_dest_1
string
LOCATION=/arch
VALID_FOR=(ALL_LOGFILES,ALL_RO
LES)
DB_UNIQUE_NAME=ora2
log_archive_dest_10
string
2
维护策略
每周2,4,7删除已经应用的归档文件
具体参见附录二
第二部分 主库正常切换
一 人工干预主库正常切换
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
1 row selected
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
在备库验证可切换状态
SQL> select switchover_status from v$database;
SWITCHOVER_STATUS
-----------------
TO_PRIMARY
1 row selected
5
将目标备库转换为主库
如果SWITCHOVER_STATUS的值为TO
STANDBY 则:
SQL>
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
如果SWITCHOVER_STATUS的值为SESSIONS
ACTIVE 则:
SQL>
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION
SHUTDOWN;
成功运行这个命令后，备库被修改为主库
6
重启目标备库
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
7
先前主库启动日志传送进程
SQL> alter database recover managed standby database
disconnect;
总结: 这样主库的一次正常切换完成.切换后的状态,原先的主库变为备库,原先的备库变为主库.
二 通过运行脚本实现主库正常切换
1
主库切换为备库
在主库上运行脚本
/admin/dataGuard/switchover/primary_to_standby.sh
2
备库切换为主库
在备库上运行脚本
/admin/dataGuard/switchover/standby_to_primary.sh
脚本1成功运行后,再运行脚本2,不能同时运行两个脚本.
经过这次切换后原来的主库变为备库,原先的备库变为主数据并且OPEN对应用提供服务.
3
复原最初状态
在原备库上运行脚本
/admin/dataGuard/switchover/primary_to_standby.sh
成功完成后
在原主库上运行脚本
/admin/dataGuard/switchover/standby_to_primary.sh
第三部分 主库灾难切换
一 人工干预主库灾难切换
二 通过运行脚本实现主库灾难切换
SQL>alter
database recover managed standby database cancel;
SQL>shutdown
immediate
SQL>startup mount
SQL>alter database set standby database
to maximize performance;
SQL>alter database recover managed standby
database finish;
-- switch
SQL>alter database commit to switchover to
primary with session shutdown;
-- open
SQL>shutdown
immediate
SQL>startup
附:
一 有选择察看redo传送与应用情况
select
message from v$dataguard_status
where
message_num>&message_num;
二 备库归档目录维护脚本
在crontab
中定制每日执行removeCommand.sh即可。
流程:每日11:50PM执行removeCommand.sh
假设今日2005-04-05
则删除04-04和04-03两日已应用归档日志.保留今日已应用归档日志
[oracle@db_gurid
admin]$ crontab -l
50 23 * * * sh
/oraguard/admin/removeCommand.sh>>removeArch.log
##################
[oracle@db_gurid
admin]$ cat removeCommand.sh
#!/bin/sh
export
ORACLE_BASE=/ora10g/app
export
ORACLE_HOME=$ORACLE_BASE/product/10.1.0/db_1
export
ORACLE_SID=ora2
cd
/oraguard/admin
$ORACLE_HOME/bin/sqlplus /nolog<
@/oraguard/admin/removeArch.sql
EOF
chmod
+x
/oraguard/admin/removeArch.sh
/oraguard/admin/removeArch.sh>>removeArch2.log
##################
[oracle@db_gurid
admin]$ cat removeArch.sql
set feed off
set heading off
set echo
off
spool removeArch.sh
select 'rm '||name from v$archived_log where
applied='YES' and completion_time>trunc(sysdate-3) and
completion_time
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/22578826/viewspace-711526/ ，如需转载，请注明出处，否则将追究法律责任。
