oracle DG 简介

2021-07-12 01:59:05

　Oracle DataGuard；简称DG。是由一个Primary Database（主库）和一个或者多个Standby Database（备库）组成。对Oracle来说；本身不能提高性能。通过数据冗余来保护数据。由Primary Database对外提供服务；用户操作在Primary Database上操作；其操作的数据库Redo Log或者Archive log通过网络传输到Standby Database。Standby Database在重做这些日志。从而实现Primary Database和Standby Database数据同步。

架构图如下：

oracle DG 简介

Oracle DataGuard中的Standby库有两种：物理Standby和逻辑Standby。

  • 逻辑Standby接收后将其转换成SQL语句，在Standby数据库上执行SQL语句实现同步，这种方式叫SQL Apply。
  • 物理Standby接收完Primary数据库生成的REDO数据后，以介质恢复的方式实现同步，这种方式也叫Redo Apply。

2|0二. Oracle DataGuard搭建

　　安装规划：

IP ROLE
192.168.1.235 Primary
192.168.1.221 Standby

2|12.1. 主库设置归档模式

alter database archivelog;

2|22.2. 主库设置Force Logging模式

alter database force logging;

2|32.3. 备库创建相应的dump文件夹

# 在主库查询对应的dump目录 select name, value from v$parameter where name in ('audit_file_dest', 'background_dump_dest', 'control_files', 'core_dump_dest', 'user_dump_dest', 'db_recovery_file_dest' ) ORDER BY name ASC; # 备库用oracle用户执行创建目录 mkdir -p $value

2|42.4. 配置Standby Redologs

　　对于模式中最大保护和最高可用性；采用是 LGWR 模式传送 Redo 日志；需要为 Standby库配置 Standby Redologs。Standby Redologs 和 ONline Redologs 文件大小是相同的。比 ONline Redologs 个数要 +1 。

# 查看redologs日志信息 SQL> select group#,type,member from v$logfile; GROUP# TYPE MEMBER ------ ---------- -------------------------------------------------- 1 ONLINE /u01/app/oradata/ora235/redo01.log 2 ONLINE /u01/app/oradata/ora235/redo02.log 3 ONLINE /u01/app/oradata/ora235/redo03.log SQL> select group#,bytes from v$log; GROUP# BYTES ------ ---------- 1 52428800 2 52428800 3 52428800 # 添加Standby Redologs；添加如下： ALTER DATABASE ADD STANDBY LOGFILE GROUP 4('/u01/app/oradata/ora235/stdred001.log') SIZE 50 M; ALTER DATABASE ADD STANDBY LOGFILE GROUP 5('/u01/app/oradata/ora235/stdred002.log') SIZE 50 M; ALTER DATABASE ADD STANDBY LOGFILE GROUP 6('/u01/app/oradata/ora235/stdred003.log') SIZE 50 M; ALTER DATABASE ADD STANDBY LOGFILE GROUP 7('/u01/app/oradata/ora235/stdred004.log') SIZE 50 M;

2|52.5. 创建实例密钥文件

  • 主库生成密钥文件
orapwd FILE=/u01/app/oracle/dbs/orapwora235 password=li0924 entries=5;
  • 将密钥文件传输到备库
scp /u01/app/oracle/dbs/orapwora235 oracle@192.168.1.221:/u01/app/oracle/dbs

2|62.6. 创建参数文件

　　本文采用 Primary 库和 Standby 库采用相同路径；所以仅设置必要的参数。

  • 主库通过spfile生成pfile文件
create pfile from spfile;
  • 添加Primary端的pfile内容如下
*.DB_UNIQUE_NAME=db_primary *.LOG_ARCHIVE_CONFIG='DG_CONFIG=(db_primary,db_standby)' *.LOG_ARCHIVE_DEST_2='SERVICE=tns_standby LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_standby' *.LOG_ARCHIVE_DEST_STATE_2=DEFER *.LOG_FILE_NAME_CONVERT ='/u01/app/oradata/ora235/','/u01/app/oradata/ora235/' *.FAL_SERVER=tns_standby *.FAL_CLIENT=tns_primary *.STANDBY_FILE_MANAGEMENT=AUTO
  • Primary重新启动
primary>create spfile from pfile; File created. primary>startup ORACLE instance started. Total System Global Area 780824576 bytes Fixed Size 2257312 bytes Variable Size 511708768 bytes Database Buffers 264241152 bytes Redo Buffers 2617344 bytes Database mounted. Database opened.
  • 复制参数文件到Standby库
scp /u01/app/oracle/dbs/initora235.ora oracle@192.168.1.221:/u01/app/oracle/dbs
  • 添加Standby端的pfile内容如下
*.DB_UNIQUE_NAME=db_standby *.LOG_ARCHIVE_CONFIG='DG_CONFIG=(db_primary,db_standby)' *.LOG_ARCHIVE_DEST_2='SERVICE=tns_primary LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_primary' *.LOG_FILE_NAME_CONVERT ='/u01/app/oradata/ora235/','/u01/app/oradata/ora235/' *.LOG_ARCHIVE_DEST_STATE_2=ENABLE *.FAL_SERVER=tns_primary *.FAL_CLIENT=tns_standby *.STANDBY_FILE_MANAGEMENT=AUTO
  • 将Standby端启动到nomount状态
[oracle@oracle221 ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Thu Aug 9 22:56:49 2018 Copyright (c) 1982, 2013, Oracle. All rights reserved. Connected to an idle instance. SQL> startup nomount; ORACLE instance started. Total System Global Area 780824576 bytes Fixed Size 2257312 bytes Variable Size 511708768 bytes Database Buffers 264241152 bytes Redo Buffers 2617344 bytes

2|72.7 配置主备库的监听文件和网络文件

  • 设置Primary库和Standby库的service_name
SQL> show parameter service_name; NAME TYPE VALUE ------------------------------------ ----------- --------------- service_names string lottu SQL> alter system set service_names='db_primary' scope=both; System altered. SQL> show parameter service_name; NAME TYPE VALUE ------------------------------------ ----------- ---------------- service_names string db_primary
  • 备库的service_name设置为db_standby；需要到参数文件修改。
*.service_names='db_standby'
  • Primary库配置listener.ora
LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.235)(PORT = 1521)(IP = FIRST))) (ADDRESS_LIST = (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC)) ) ) ) SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (SID_NAME = ora235) (GLOBAL_DBNAME = db_primary) (ORACLE_HOME =/u01/app/oracle) ) )
  • Standby库配置listener.ora
LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.221)(PORT = 1521)(IP = FIRST))) (ADDRESS_LIST = (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC)) ) ) ) SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (SID_NAME = ora235) (GLOBAL_DBNAME = db_standby) (ORACLE_HOME =/u01/app/oracle) ) )
  • Primary库和Standby库设置tnsname.ora
tns_primary= (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.235)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = db_primary) ) (HS = OK) ) tns_standby= (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.221)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = db_standby) ) (HS = OK) )

　　重启监听lsnrctl restart

2|82.8. 克隆Standby库

在Primary库执行

[oracle@oracle235 admin]$ rman target sys/li0924@tns_primary auxiliary sys/li0924@tns_standby Recovery Manager: Release 11.2.0.4.0 - Production on Thu Aug 9 23:56:46 2018 Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved. connected to target database: ORA235 (DBID=2047494122) connected to auxiliary database: ORA235 (not mounted) RMAN> DUPLICATE TARGET DATABASE FOR STANDBY FROM ACTIVE DATABASE DORECOVER NOFILENAMECHECK; Starting Duplicate Db at 09-AUG-18 using target database control file instead of recovery catalog allocated channel: ORA_AUX_DISK_1 channel ORA_AUX_DISK_1: SID=20 device type=DISK contents of Memory Script: { backup as copy reuse targetfile '/u01/app/oracle/dbs/orapwora235' auxiliary format '/u01/app/oracle/dbs/orapwora235' ; } executing Memory Script Starting backup at 09-AUG-18 allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=26 device type=DISK Finished backup at 09-AUG-18 contents of Memory Script: { backup as copy current controlfile for standby auxiliary format '/u01/app/oradata/ora235/control01.ctl'; restore clone controlfile to '/u01/app/oradata/ora235/control02.ctl' from '/u01/app/oradata/ora235/control01.ctl'; } executing Memory Script Starting backup at 09-AUG-18 using channel ORA_DISK_1 channel ORA_DISK_1: starting datafile copy copying standby control file output file name=/u01/app/oracle/dbs/snapcf_ora235.f tag=TAG20180809T235658 RECID=4 STAMP=983750219 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01 Finished backup at 09-AUG-18 Starting restore at 09-AUG-18 using channel ORA_AUX_DISK_1 channel ORA_AUX_DISK_1: copied control file copy Finished restore at 09-AUG-18 contents of Memory Script: { sql clone 'alter database mount standby database'; } executing Memory Script sql statement: alter database mount standby database contents of Memory Script: { set newname for tempfile 1 to "/u01/app/oradata/ora235/temp01.dbf"; switch clone tempfile all; set newname for datafile 1 to "/u01/app/oradata/ora235/system01.dbf"; set newname for datafile 2 to "/u01/app/oradata/ora235/sysaux01.dbf"; set newname for datafile 3 to "/u01/app/oradata/ora235/undotbs01.dbf"; set newname for datafile 4 to "/u01/app/oradata/ora235/users01.dbf"; set newname for datafile 5 to "/data/oracle/data/lottu01.dbf"; backup as copy reuse datafile 1 auxiliary format "/u01/app/oradata/ora235/system01.dbf" datafile 2 auxiliary format "/u01/app/oradata/ora235/sysaux01.dbf" datafile 3 auxiliary format "/u01/app/oradata/ora235/undotbs01.dbf" datafile 4 auxiliary format "/u01/app/oradata/ora235/users01.dbf" datafile 5 auxiliary format "/data/oracle/data/lottu01.dbf" ; sql 'alter system archive log current'; } executing Memory Script executing command: SET NEWNAME renamed tempfile 1 to /u01/app/oradata/ora235/temp01.dbf in control file executing command: SET NEWNAME executing command: SET NEWNAME executing command: SET NEWNAME executing command: SET NEWNAME executing command: SET NEWNAME Starting backup at 09-AUG-18 using channel ORA_DISK_1 channel ORA_DISK_1: starting datafile copy input datafile file number=00005 name=/data/oracle/data/lottu01.dbf output file name=/data/oracle/data/lottu01.dbf tag=TAG20180809T235706 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:01:45 channel ORA_DISK_1: starting datafile copy input datafile file number=00001 name=/u01/app/oradata/ora235/system01.dbf output file name=/u01/app/oradata/ora235/system01.dbf tag=TAG20180809T235706 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:35 channel ORA_DISK_1: starting datafile copy input datafile file number=00002 name=/u01/app/oradata/ora235/sysaux01.dbf output file name=/u01/app/oradata/ora235/sysaux01.dbf tag=TAG20180809T235706 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:35 channel ORA_DISK_1: starting datafile copy input datafile file number=00003 name=/u01/app/oradata/ora235/undotbs01.dbf output file name=/u01/app/oradata/ora235/undotbs01.dbf tag=TAG20180809T235706 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:25 channel ORA_DISK_1: starting datafile copy input datafile file number=00004 name=/u01/app/oradata/ora235/users01.dbf output file name=/u01/app/oradata/ora235/users01.dbf tag=TAG20180809T235706 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01 Finished backup at 10-AUG-18 sql statement: alter system archive log current contents of Memory Script: { backup as copy reuse archivelog like "/data/arch/1_3_983660602.dbf" auxiliary format "/data/arch/1_3_983660602.dbf" ; catalog clone archivelog "/data/arch/1_3_983660602.dbf"; switch clone datafile all; } executing Memory Script Starting backup at 10-AUG-18 using channel ORA_DISK_1 channel ORA_DISK_1: starting archived log copy input archived log thread=1 sequence=3 RECID=19 STAMP=983750428 output file name=/data/arch/1_3_983660602.dbf RECID=0 STAMP=0 channel ORA_DISK_1: archived log copy complete, elapsed time: 00:00:01 Finished backup at 10-AUG-18 cataloged archived log archived log file name=/data/arch/1_3_983660602.dbf RECID=1 STAMP=983750429 datafile 1 switched to datafile copy input datafile copy RECID=4 STAMP=983750429 file name=/u01/app/oradata/ora235/system01.dbf datafile 2 switched to datafile copy input datafile copy RECID=5 STAMP=983750429 file name=/u01/app/oradata/ora235/sysaux01.dbf datafile 3 switched to datafile copy input datafile copy RECID=6 STAMP=983750429 file name=/u01/app/oradata/ora235/undotbs01.dbf datafile 4 switched to datafile copy input datafile copy RECID=7 STAMP=983750429 file name=/u01/app/oradata/ora235/users01.dbf datafile 5 switched to datafile copy input datafile copy RECID=8 STAMP=983750429 file name=/data/oracle/data/lottu01.dbf contents of Memory Script: { set until scn 955597; recover standby clone database delete archivelog ; } executing Memory Script executing command: SET until clause Starting recover at 10-AUG-18 using channel ORA_AUX_DISK_1 starting media recovery archived log for thread 1 with sequence 3 is already on disk as file /data/arch/1_3_983660602.dbf archived log file name=/data/arch/1_3_983660602.dbf thread=1 sequence=3 media recovery complete, elapsed time: 00:00:00 Finished recover at 10-AUG-18 Finished Duplicate Db at 10-AUG-18

2|92.9. 启用日志传送

在 Primary 端启动日志传送

alter system set LOG_ARCHIVE_DEST_STATE_2=ENABLE;

2|102.10. 启用实时应用redo

　　在 Primary Database 产生的 Redo 日志；传送到 Standby Database；是通过 LGWR 或者 ARCH 进程完成。这个很好理解。默认情况下是由 ARCH 进程。有参数 *.LOG_ARCHIVE_DEST_2 控制的。使用 ARCH 进程； Primary Database 和 Standby Database 存在数据延迟。若 Primary Database 出现异常；容易造成部分数据丢失。为了避免数据丢失，必须要使用 LGWR 进程，需要用到 Standby Redolog。而LGWR 又分SYNC（同步）和ASYNC（异步）两种方式。

  • SYNC方式：对网络要求比较高；必须等待写入本地日志文件操作和通过LNSn进程的网络传送都成功，Primary Database 上的事务才能提交成功。使用LGWR SYNC方式时，可以同时使用NET_TIMEOUT参数，这个参数单位是秒，代表如果多长时间内网络发送没有响应，LGWR 进程会抛出错误。因此对 Primary Database 性能有影响。
*.LOG_ARCHIVE_DEST_2='SERVICE=tns_standby LGWR SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_standby NET_TIMEOUT = 30'
  • ASYNC方式：采用异步方式；Primary Database 上的事务提交跟日志是否已经传送没有影响。
*.LOG_ARCHIVE_DEST_2='SERVICE=tns_standby LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_standby'

1. 在 Primary Database上执行；

alter system set log_archive_dest_2='SERVICE=tns_standby LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_standby' scope=both;

2. 在Standby Database上执行；

alter system set log_archive_dest_2='SERVICE=tns_primary LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=db_primary' scope=both;

3. Standby Database启动实时应用redo

alter database recover managed standby database using current logfile ;

4. 验证结果

# 在Primary Database 上创建表t_lottu02 SQL> set SQLPROMPT Primary> Primary>conn lottu/li0924 Connected. Primary>create table t_lottu02 as select level id,'lottu' name from dual connect by level <= 3; Table created. # 在Standby Database上查看 SQL> set SQLPROMPT StandBy> StandBy>conn lottu/li0924 Connected. StandBy>select * from t_lottu02; ID NAME ---------- ----- 1 lottu 2 lottu 3 lottu

 

原文：https://www.cnblogs.com/lottu/p/9542053.html

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