oracle dg状态检查及相关命令

oracle dg 状态检查

先检查备库的归档日志同步情况 

select name,applied from v$archived_log; 

alter database recover managed standby database cancel;

select thread#,sequence#,standby_dest,archived,applied,status from v$archived_log order by 1,2;

alter database recover managed standby database using current logfile disconnect from session;

.在备库 查看gap

1.      select * from v$archive_gap;

alter  database recover managed standby  database disconnect from session;

查看主库的基本信息：

sys@enmo1 hey~1->select open_mode,protection_mode,database_role,switchover_status from v$database;

open_mode            protection_mode             database_role         switchover_status
-------------------- ----------------------------- ------------------------ ------------------------
read write           maximum performance      primary                      to standby

查看备库的基本信息：

sys@enmo2 hey~2->select open_mode,protection_mode,database_role,switchover_status from v$database;

open_mode                   protection_mode             database_role         switchover_status
------------------------- ----------------------------- ------------------------ ------------------------
read only with apply maximum performance      physical standby      not allowed

备库应用日志保持和主库数据一致（如果不一致，执行如下语句应用日志）

sys@enmo2 hey~2->recover managed standby database using current logfile disconnect from session;
media recovery complete.

sys@enmo2 hey~2->recover managed standby database cancel;
media recovery complete.

主库切换到备库角色并查看切换之后的状态为recovery needed

sys@enmo1 hey~1->alter database commit to switchover to physical standby with session shutdown;

database altered.

sys@enmo1 hey~1->shutdown abort;

oracle instance started.

total system global area 830930944 bytes
fixed size 2257800 bytes
variable size 700451960 bytes
database buffers 121634816 bytes
redo buffers 6586368 bytes
database mounted.
sys@enmo1 hey~1->select switchover_status from v$database;

switchover_status
--------------------
recovery needed

切换应用日志，然后在查看切换状态为to primary正常：

sys@enmo1 hey~1->recover managed standby database using current logfile disconnect from session;
media recovery complete.
sys@enmo1 hey~1->select switchover_status from v$database;

switchover_status
--------------------
to primary

备库切主库：

sys@enmo2 hey~2->select open_mode,protection_mode,database_role,switchover_status from v$database;

open_mode protection_mode database_role switchover_status
-------------------- -------------------- ---------------- --------------------
mounted maximum performance physical standby to primary

sys@enmo2 hey~2->alter database commit to switchover to primary with session shutdown;

database altered.

sys@enmo2 hey~2->alter database open;

database altered.

sys@enmo2 hey~2->select switchover_status,database_role from v$database;

switchover_status database_role
-------------------- ----------------
failed destination primary

sys@enmo2 hey~2->select open_mode,protection_mode,database_role from v$database;

open_mode protection_mode database_role
-------------------- -------------------- ----------------

read write maximum performance primary

二、备库不同步的问题检查方法

1、检查主备两边的序号
select max(sequence#) from v$log;   ---检查发现一致

2、备库执行，查看是否有数据未应用
select name,sequence#,applied from v$archived_log order by sequence#;

select sequence#,first_time,next_time ,applied from v$archived_log order by 1;

3、检查备库是否开启实时应用
select recovery_mode from v$archive_dest_status where dest_id=2;

4、检查备库状态
select switchover_status from v$database; --发现状态not allowed 

3、看看进程mrp是否存在
 ps aux|grep mrp      --发现进程不存在

4、如果不存在执行以下：
alter database recover managed standby database using current logfile disconnect;

alter database recover managed standby database disconnect from session;  --后台执行

alter database recover managed standby database --前台执行，执行这个可以看到报错的情况

如果有报错，查看alert日志和log.xml日志 

5、验证是否正常
select process,status from v$managed_standby;
select process,status,sequence# from v$managed_standby;

如果看到mrp0正常

6、以上步骤处理好后，如果数据还不正常，接着处理

关闭备库，接着处理：
把主库上 undotbs01.dbf 文件，物理的重拷到备库机上以前undotbs01.dbf 所在目录下；

$scp /data/oracle/oradata/voip/undotbs01.dbf   192.168.122.204:/data/oracle/oradata/voip

再在主库上重新生成一个standby control file ，拷到备库机上相应目录下，

alter database create standby controlfile as '/data/oracle/oradata/voip/qyqdg01.ctl'

$scp /data/oracle/oradata/voip/qyqdg01.ctl   192.168.122.204:/data/oracle/oradata/voip
$ mv qyqdg01.ctl  control01.ctl
$ cp control01.ctl /data/oracle/flash_recovery_area/qyq/
$cd /data/oracle/flash_recovery_area/qyq/
$ mv control01.ctl  control02.ctl

接着
startup nomount;
alter database mount standby database;
alter database recover managed standby database disconnect from session;

--------------------------------------
session恢复完成后，重启打开备库；

alter database open read only;