ORACLE dataguard 主备库延迟 using current logfile

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/EVISWANG/article/details/77838369

一. 问题描述：

       BI分析部门反映夜间拉取的ORACLE备库数据和业务部门导入主库的数据不一致，之间相差近2个小时。

二. 问题分析：

     第一反映备库归档有GAP，主备库延迟，经过查询发现主备库归档并无延迟

SQL> select process, status, sequence# , ACTIVE_AGENTS from v$managed_standby;

PROCESS   STATUS        SEQUENCE# ACTIVE_AGENTS
--------- ------------ ---------- -------------
ARCH      CLOSING            1468             0
ARCH      CLOSING            1469             0
ARCH      CONNECTED             0             0
ARCH      CLOSING            1470             0
RFS       IDLE                  0             0
RFS       IDLE               1471             0
RFS       IDLE                  0             0
MRP0      WAIT_FOR_LOG       1471            41
RFS       IDLE                  0             0

9 rows selected.

     第二种可能性夜间网络延迟等故障导致主备库数据不一致，经过检查alert等并未发现任何异常

     手工在主库做测试新建test表，插入数据.....发现确实未同步到备库，且一切正常无任何报错等。

主库测试：
SQL> create table tevis (id number(10),
  2  name varchar2(10));
Table created.
SQL> insert into tevis values(1, 'anhui');
1 row created.
SQL> commit;
Commit complete.
SQL> 
备库查询：
SQL> select * from tevis;
select * from evisevis           *
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> 

   查询备库v$dataguard_stats视图：

SQL> select * from v$dataguard_stats ;
NAME                             VALUE                UNIT                           TIME_COMPUTED                  DATUM_TIME
-------------------------------- -------------------- ------------------------------ ------------------------------ ------------------------------
transport lag                    +00 00:00:00         day(2) to second(0) interval   09/04/2017 16:03:23            09/04/2017 16:03:22
apply lag                        +00 04:02:49         day(2) to second(0) interval   09/04/2017 16:03:23            09/04/2017 16:03:22
apply finish time                +00 00:00:00.290     day(2) to second(3) interval   09/04/2017 16:03:23
estimated startup time           9                    second                         09/04/2017 16:03:23
SQL> 

发现apply log竟已经达到了4h只多。

手工  alter system switch logfile;

发现备库测试数据tevis表数据已经同步，而且v$dataguard_stats中apply log 为零。

因此：导致主备库延迟的原因为 not apply current logfile

三. 问题处理：

SQL> alter  database recover managed  standby  database  cancel;
Database altered.
SQL> alter database recover managed standby database using current logfile disconnect;
Database altered.
SQL>

    再去查询视图v$dataguard_stats

SQL> select * from v$dataguard_stats;
NAME                             VALUE                UNIT                           TIME_COMPUTED                  DATUM_TIME
-------------------------------- -------------------- ------------------------------ ------------------------------ ------------------------------
transport lag                    +00 00:00:00         day(2) to second(0) interval   09/04/2017 16:10:54            09/04/2017 16:10:52
apply lag                        +00 00:00:00         day(2) to second(0) interval   09/04/2017 16:10:54            09/04/2017 16:10:52
apply finish time                                     day(2) to second(3) interval   09/04/2017 16:10:54
estimated startup time           9                    second                         09/04/2017 16:10:54
SQL>