oracle dg狀態檢查及相關命令

oracle dg 狀態檢查

先檢查備庫的歸檔日誌同步情況 

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;

.在備庫 查看gap

1.      select * from v$archive_gap;

ALTER  DATABASE RECOVER MANAGED STANDBY  DATABASE DISCONNECT FROM SESSION;

查看主庫的基本信息：

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

查看備庫的基本信息：

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

備庫應用日誌保持和主庫數據一致（如果不一致，執行如下語句應用日誌）

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.

主庫切換到備庫角色並查看切換之後的狀態為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

切換應用日誌，然後在查看切換狀態為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

備庫切主庫：

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、備庫不同步的問題檢查方法

1、檢查主備兩邊的序號
select max(sequence#) from v$log;   ---檢查發現一致

2、備庫執行，查看是否有數據未應用
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、檢查備庫是否開啟實時應用
select recovery_mode from v$archive_dest_status where dest_id=2;

4、檢查備庫狀態
select switchover_status from v$database; --發現狀態not allowed 

3、看看進程MRP是否存在
 ps aux|grep mrp      --發現進程不存在

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

alter database recover managed standby database disconnect from session;  --後臺執行

alter database recover managed standby database --前臺執行，執行這個可以看到報錯的情況

如果有報錯，查看alert日誌和log.xml日誌 

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

如果看到mrp0正常

6、以上步驟處理好後，如果數據還不正常，接著處理

關閉備庫，接著處理：
把主庫上 undotbs01.dbf 文件，物理的重拷到備庫機上以前undotbs01.dbf 所在目錄下；

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

再在主庫上重新生成一個standby control file ，拷到備庫機上相應目錄下，

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

接著
STARTUP NOMOUNT;
ALTER DATABASE MOUNT STANDBY DATABASE;
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

--------------------------------------
session恢復完成後，重啟打開備庫；

alter database open read only;