Oracle 10G windows 平台 DataGuard 范例(三)

Oracle 10G windows 平台 DataGuard 实例(三)

7. 启动备用数据库?-

C:>set ORACLE_SID=orcl -

SQL>sqlplus "/as sysdba" -

SQL>startup nomount pfile='D:/oracle/product/10.2.0/db_1/database/initorcl.ora'; -

SQL>create spfile from pfile='D:/oracle/product/10.2.0/db_1/database/initorcl.ora'; -

若采用Rman备份的, 则在此standby 端进行 Rman还原数据库：-

$rman target?sys/admin@primary?auxiliary /-

RMAN> duplicate target database for standby dorecover nofilenamecheck;

SQL>alter database mount standby database ; -

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

---------------------------------------?-

测试?-

主备查询结果一致，Data?Guard?搭建结束。

1. 测试主库产生的归档日志是否能正常传送到归档日志?-

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D:/arch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. 可以在备库坐如下操作： -

alter database recover managed standby database cancel; -

alter database recover managed standby database disconnect from session; -

-----------------------------------?-

主备库切换?-

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： -

确认主库和从库间网络连接通畅； -

确认没有活动的会话连接在数据库中； -

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

确保STANDBY数据库处于ARCHIVELOG模式； -

如果设置了REDO应用的延迟，那么将这个设置去掉； -

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; -

??????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，如果大家在测试不成功的时候再和我说，让我看看在什么情况下会不成功。 -

?? -

???? 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; -

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 -

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; -

注意地方:?-

如果做了switchover,主库参数设置成以下方式，会触发ora-16009错误 -

Alert system set log_archive_dest_2=’service=primary -

DB_UNIQUE_NAME=orcl’ scope=spfile; -

然后再alert_orcl.log 日志中会出现以下错误内容 -

Thu Nov 27 10:19:12 2008 -

Redo Shipping Client Connect -

-- Connected User is Valid -

RFS[2]: Assigned to RFS process 1292 -

RFS[2]: Database mount ID mismatch [0x4781d95f:0x47823be1] -

RFS[2]: Client instance is standby database i -

RFS[2]: Not using real app -

Thu Nov 27 10:19Errors in file -

d:/oracle/product/10.2.0/admin/orcl/udump/orc -

ORA-16009: 远程归档日 -

从metalink上查到: -

* fact: Oracle Server - Enterprise Edition 9 -

* symptom: Errors appears in alert.log on primary database -

* symptom: RFS: client instance is standby database instead -

* symptom: RFS: Not using real application clusters -

* symptom: Errors appear in alert.log on standby database -

* symptom: -

database -

standby database -

primary database -

* symptom: Standby redo log files are defined on the standby database -

* cause: The standby redo log files are synchronously filled with redo -

from the primary database. When a logswitch occur on the primary database, -

those files are archived on the standby database before being applyed on -

it. The archiving process on the standby database should only archive to -

the local disks on tprimarfix: -

Disable the remote archiving on the standby databasExample: alter system set log_archive_dest_2 = '' -

是因为没有把standby 上的log_archive_dest_2 清空导致的。 -

另外也有可 -

bug 4676659 -

Standby may not be recognised (ORA-16009) -

When the log transport is LGWR ASYNC and logical standby has -

LOG_ARCHIVE_DEST setting VALID_FOR=(ONLINE_LOGFILE, PRIMARY_ROLE) -

ORA-16009 is reportedregular interWorkaround: -

There is no workaround to prevent ORA-16009 from appearing in alert logs. -

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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Oracle 10G windows 平台 DataGuard 范

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