DG日志不应用，GAP,主备切换解决思路与办法
DG日志不应用，GAP,主备切换解决思路与办法环境ORACLE 10G OS WINDOWS对于DG故障解决思路，DG日志切换不进行应用，DG出现GAP解决方法，DG主备库切换，当DG出现故障时，第一时间检测alert日志，服务器OS日志,网络是否通畅。1、当DG出现日志不能传输到备库一、TNS配置错误，监听配置错误。二、主备库初始化参数文件配置错误（如archive_log_dest文件位置错误)。三、备库控制文件过旧，从主库生成一个STANDBY CONTROL过去。SQL> alter database create standby controlfile as 'c:\control01.ctl';。四、备库是否应用了Failovers 。下面模拟备库应用了Failovers 。备库执行SQL> alter database recover managed standby database finish;Database altered.备库：SQL> select PROTECTION_MODE,OPEN_MODE,DB_UNIQUE_NAME,DATABASE_ROLE,SWITCHOVER_STATUS from v$database;PROTECTION_MODE OPEN_MODE DB_UNIQUE_NAME DATABASE_ROLE SWITCHOVER_STATUS-------------------- -------------------- ------------------------------ ---------------- --------------------MAXIMUM PERFORMANCE READ ONLY PRIMARY PHYSICAL STANDBY TO PRIMARY主库：SQL> select PROTECTION_MODE,OPEN_MODE,DB_UNIQUE_NAME,DATABASE_ROLE,SWITCHOVER_STATUS from v$database;PROTECTION_MODE OPEN_MODE DB_UNIQUE_NAME DATABASE_ROLE SWITCHOVER_STATUS-------------------- -------------------- ------------------------------ ---------------- --------------------MAXIMUM PERFORMANCE READ WRITE STANDBY PRIMARY SESSIONS ACTIVE主库alert文件：ARC1: All Archive destinations made inactive due to error 394ARC1: Failed to archive thread 1 sequence 1 (394)ARCH: Archival stopped, error occurred. Will continue retryingWed Oct 30 10:25:54 2013Errors in file c:\oracle\product\10.2.0\admin\orcl\bdump\orcl_arc1_1236.trc:ORA-16038: log 2 sequence# 1 cannot be archivedORA-00394: online log reused while attempting to archive itORA-00312: online log 2 thread 1: 'C:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\STANDBY\ONLINELOG\O1_MF_2_96YY5JSW_.LOG'ARC1: All Archive destinations made inactive due to error 394*** 2013-10-30 10:25:54.796 58942 kcrr.ckcr易做图il: dest:1 err:394 force:0 blast:1*** 2013-10-30 10:25:54.828 20146 kcrr.cORA-16038: log 2 sequence# 1 cannot be archivedORA-00394: online log reused while attempting to archive itORA-00312: online log 2 thread 1: 'C:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\STANDBY\ONLINELOG\O1_MF_2_96YY5JSW_.LOG'*** 2013-10-30 10:27:54.734*** 2013-10-30 10:27:54.734 20146 kcrr.c*** 2013-10-30 10:28:54.765kcrrwkx: work to do 0x1 (start)*** 2013-10-30 10:28:54.781 20146 kcrr.c这个时候导致主库不再向备库传送日志了,我们只需要重建STANDBY控制文件就行SQL> alter database create standby controlfile as 'c:\control01.ctl';。其中当真正主库出现故障的Failovers的时候一.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：二. 然后停止应用归档：SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;三. 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;SQL> SELECT DATABASE_ROLE FROM V$DATABASE;DATABASE_ROLE----------------PHYSICAL STANDBYSQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;2、日志传输到备库不能应用。一、是否产生了GAP 拷贝缺失的日志重新注册日志，如果GAP缺失的归档日志过多，切归档日志已经删除了，那就必须重新搭建DG。二、是否设置了REDO延迟下面就简单说说手工处理日志GAP的步骤：1、在备库检查是否有日志缺失SQL> select * from V$ARCHIVE_GAP;2、在主库中查询缺失的日志的所在路径和名称SQL> SELECT NAME FROM V$ARCHIVED_LOG如果把日志移动到其他路径，则把日志所在路径换成当前实际所在路径。3、把日志拷贝到备库上4、在备库上手工注册上一步中从主库拷贝来的日志SQL> ALTER DATABASE REGISTER LOGFILE '路径';5、观察备库的alert日志信息6、检查备库是否还有日志GAPSQL> select * from V$ARCHIVE_GAP;no rows selected如果有行返回，则重复2-5步，直到查询结果是"no rows selected"。如果日志只是临时移动到其他地方，过后会再移回原路径，则不用这么大费周折手工去手工处理了，把日志拷回原处后FAL会自动处理GAP。3、DG主备库切换主库： -1. 查看switchover 状态 -SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE; -to standby2 切换成备库如果上面的结果不是to standby 还有会话运行SQL>Alter database commit to switchover to physical standby with session shutdown;否则直接SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY;Database altered.3 启动到mount和应用日志状态SQL> SHUTDOWN IMMEDIATESQL> startup nomount;SQL> alter database mount standby database;SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;4. 查看数据库模式SQL>select dest_name,status,database_mode,recovery_mode,protection_mode from v$archive_dest_status;SQL>select status,database_mode from v$archive_dest_status;上一个：收缩Oracle数据文件
下一个：11gR2单实例dbca静默建库
