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Data Guard出现gap sequence修复

Oracle DG系统出现FAL[server/client]:Failed to request gap sequence问题，详细记录第一步修复和诊断工作

一、出现gap sequence现象

备库

Fetching gap sequence in thread 1, gap sequence 710-716

Tue May 31 15:02:38 2011

FAL[client]: Failed to request gap sequence

GAP - thread 1 sequence 710-716

DBID 3240478808 branch 746916894

FAL[client]: All defined FAL servers have been attempted.

-------------------------------------------------------------

Check that the CONTROL_FILE_RECORD_KEEP_TIME initialization

parameter is defined to a value that is sufficiently large

enough to maintain adequate log switch information to resolve

archivelog gaps.

-------------------------------------------------------------

主库

Tue May 31 13:50:47 2011

FAL[server]: Fail to queue the whole FAL gap

GAP - thread 1 sequence 710-716

DBID 3240478808 branch 746916894

二、修复操作

1、查询备库的scn

SQL> SELECT CURRENT_SCN FROM V$DATABASE;

CURRENT_SCN

-----------

1154337

--在出现意外datafile header scn不一致的时候,需要根据提示归档日志,找出最小scn

2、确定主库是否添加数据文件

SQL> select FILE#,name from v$datafile where CREATION_CHANGE#> =1154337;

no rows selected

确定主库在这个scn之后是否有添加数据文件，如果添加文件，需要手工在备库添加

3、备库停止日志应用

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

4、主库增量备份并传输到备库上

主库进行增量备份

RMAN> BACKUP INCREMENTAL FROM SCN 1154337 DATABASE

FORMAT '/home/oracle/xff_%U' tag 'XIFENFEI';

[oracle@localhost ~]$ scp xff* 192.168.1.30:/home/oracle/rman

说明：主库之前必须要做过rman的全备(没有全备的库，基于scn的增量备份也能够成功)

5、备库上进行恢复

RMAN> CATALOG START WITH '/home/oracle/rman';

RMAN> RECOVER DATABASE NOREDO;

说明：CATALOG START WITH是10g及其以后版本中才存在功能，没有该功能可以采用catalog或者复制主库的控制文件，rman备份放置和主库备份时相同目录实现。

6、主库上创建standby controlfile文件并传输到备库

RMAN> BACKUP CURRENT CONTROLFILE FOR STANDBY

FORMAT '/home/oracle/xff_ctl.bck';

[oracle@localhost ~]$ scp xff_ctl.bck 192.168.1.30:/home/oracle/rman

创建standby controlfile两步可以需要根据实际情况考虑,大多数情况下不需要

7、备库恢复控制文件

RMAN> shutdown;

RMAN> STARTUP NOMOUNT;

RMAN> RESTORE STANDBY CONTROLFILE FROM '/home/oracle/rman/xff_ctl.bck';

RMAN> alter database mount;

8、清空备库日志组

SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;

注：如果采用了standby log模式，不需要清空，如果清空会出现

SQL> ALTER DATABASE CLEAR LOGFILE GROUP 1;

ALTER DATABASE CLEAR LOGFILE GROUP 1

*

ERROR at line 1:

ORA-19527: physical standby redo log must be renamed

ORA-00312: online log 1 thread 1: '/u01/oradata/xienfei/redo01.log'

说明：如果没有采用standby log模式，有几组需要清空几组

9、备库重设flashback

SQL> ALTER DATABASE FLASHBACK OFF;

SQL> ALTER DATABASE FLASHBACK ON;

10、备库重新接收并应用日志

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

三、修复成功标志

1、sql中操作

在主库中执行alter system switch logfile;

分别主备库中执行select max(sequence#) from v$archived_log;如果一致标示修复成功

2、通过alert文件

主库

PING[ARC0]: Error 3113 when pinging standby xff.

Tue May 31 14:11:51 2011

Thread 1 advanced to log sequence 719

Current log# 3 seq# 719 mem# 0: /u01/oradata/xienfei/redo03.log

Tue May 31 14:20:05 2011

Thread 1 advanced to log sequence 720

Current log# 1 seq# 720 mem# 0: /u01/oradata/xienfei/redo01.log

Tue May 31 14:20:16 2011

ARC0: Standby redo logfile selected for thread 1 sequence 719 for destination LOG_ARCHIVE_DEST_2

备库

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION

Tue May 31 15:30:37 2011

Attempt to start background Managed Standby Recovery process (xff)

MRP0 started with pid=18, OS id=14704

Tue May 31 15:30:37 2011

MRP0: Background Managed Standby Recovery process started (xff)

Managed Standby Recovery not using Real Time Apply

parallel recovery started with 2 processes

Media Recovery Log /u01/archive/1_718_746916894.arc

Tue May 31 15:30:43 2011

Completed: ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION

Tue May 31 15:30:52 2011

RFS[1]: Successfully opened standby log 4: '/u01/oradata/xienfei/s_redo1.log'

Media Recovery Log /u01/archive/1_719_746916894.arc

Media Recovery Waiting for thread 1 sequence 720

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