一、环境描述

切换前：

切换后

二、 D G 正常切换

DG 切换前，会停止业务，我们在停止业务后检查 O GG 的状态，确保已经挖掘到最新的

2 .1 OGG 进程检查并停止

查看 O GG 挖掘进程是否挖掘到最新，如果为 E OF 则是最新的，则可以停止进程，否则需要等待挖掘到最新时才能停。

GGSCI (oradb) 2> send xjm_ext status

Sending STATUS request to EXTRACT XJM_EXT ...

EXTRACT XJM_EXT (PID 26888)

   Current status: Recovery complete: At EOF

  Current read position:

  Redo thread #: 1

  Sequence #: 4

  RBA: 1426944

  Timestamp: 2021-12-22 11:08:46.000000

  SCN: 2979.1786729399 (12796494304183)

  Current write position:

  Sequence #: 37

  RBA: 1433

  Timestamp: 2021-12-22 11:08:43.350762

  Extract Trail: ./dirdat/xj

停止挖掘和传输进程

GGSCI (oradb) 26> stop xjm_ext

Sending STOP request to EXTRACT XJM_EXT ...

Request processed.

GGSCI (oradb) 27> stop xjm_dmp

Sending STOP request to EXTRACT XJM_DMP ...

Request processed.

GGSCI (oradb) 29> stop mgr

2 .2NFS 挂载 OGG 目录

安装并配置 nfs

检查是否安装 N FS

rpm -qa|grep nfs

rpm -qa|grep portmap

若没安装，则手工安装

rpm -ivh nfs-

rpm -ivh portmap

服务器端配置

vi /etc/exports

添加：

/ o gg12 192.168.238.57(rw,sync,no_root_squash,no_all_squash,no_subtree_check)

启动 NFS 服务器

# service portmap start

# service nfs start

若已经启动则重启：

# service portmap restart

# service nfs restart

查看共享的服务

[root@oradb ~]# showmount -e

Export list for oradb:

/ogg12 192.168.238.57

客户端挂载共享目录

创建目录

m kdir  /ogg12

mount -t nfs -o nolock,rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,actimeo=0,noac,nfsvers=3,timeo=600 192.168.238.56:/ogg 12   /ogg 12

2 .3 现生产端启动 OGG

GGSCI (ogg) 2> start mgr

Manager started.

GGSCI (ogg) 3> start xjm_ext

Sending START request to MANAGER ...

EXTRACT XJM_EXT starting

GGSCI (ogg) 4> start xjm_dmp

Sending START request to MANAGER ...

EXTRACT XJM_DMP starting

2 .4 OGG 报错查看

OGG 在生产库启动后，查看挖掘进程的信息

GGSCI (ogg) 3> info xjm_ext

EXTRACT    XJM_EXT   Last Started 2021-12-22 10:42   Status ABENDED

Checkpoint Lag       00:00:00 (updated 00:01:10 ago)

Log Read Checkpoint  Oracle Redo Logs

                     2021-12-22 10:13:02  Seqno 31, RBA 3136512

                     SCN 2979.1786705102 (12796494279886)

查看报错信息

2021-12-22 10:42:40  ERROR   OGG-02803  Oracle GoldenGate Capture for Oracle, xjm_ext.prm:  Encountered a Data Guard role transition. Alter Extract to SCN 12,796,494,300,848 and restart Extract, or recreate Extract with the correct number of threads at SCN 12,796,494,300,848.

2 .2 重新指定 S CN

我们可以看到报错信息里提示：因为数据库的角色进行转换，需要重新指定 scn 号。

GGSCI (ogg) 4> alter xjm_ext,scn 12796494300848

EXTRACT altered.

GGSCI (ogg) 5> info xjm_ext

EXTRACT    XJM_EXT   Initialized   2021-12-22 10:45   Status STOPPED

Checkpoint Lag       00:00:00 (updated 00:00:09 ago)

Log Read Checkpoint  Oracle Redo Logs

                     First Record         Seqno 0, RBA 0

                     SCN 2979.1786726064 (12796494300848)

2 .4 启动挖掘进程

启动挖掘进程

GGSCI (oradb) 22> start  xjm_ext