1.故障现象

RMAN duplicate from active 时遭遇 ORA-17627 ORA-12528 ORA-17629

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 10/08/2018 10:51:07
RMAN-05501: aborting duplication of target database
RMAN-03015: error occurred in stored script Memory Script
RMAN-06136: Oracle error from auxiliary database: ORA-17629: Cannot connect to the remote database server
ORA-17627: ORA-12528: TNS:listener: all appropriate instances are blocking new connections
ORA-17629: Cannot connect to the remote database server

2.问题分析

出现该问题，从 ORA-12528: TNS:listener: all appropriate instances are blocking new connections 来看，应该是主从数据库的连接出问题。

在执行脚本backup as copy reuse时出现了错误，也就是说备份的时候出现错误 RMAN-03009
其次是ORA-17629，不能连接到远程数据库服务器，ORA-17627后跟着ORA-12528，说明是由于无法解析字符串

使用 dumpcation 从主数据库进行克隆，因此主数据库的数据文件等等应当会通过网络复制到辅助数据库，通过Oracle Net 网络连接进行复制。
使用 rman 在辅助数据库连接到target DB以及到Auxiliary DB，target DB端也要连接到Auxiliary DB传送文件。
需要配置两个服务器之间都配置到target DB与Auxiliary DB的tnsnames。

3.解决方法

出现这个问题的原因是当使用动态注册监听时，当实例处于限制模式或受阻的情况下PMON将会更新监听程序来阻新的连接，解决方法其实有两种：

1. 在tns连接描述串中增加(UR=A)子句来让动态监听程序使用service_name来进行注册

ORCL =
    (DESCRIPTION =
    (ADDRESS =
        (PROTOCOL = TCP)(HOST = WELL)(PORT = 1521))
        (CONNECT_DATA =
        (SERVER = DEDICATED)
        (SERVICE_NAME = SCMPRD02)
        (UR = A))
   )

2. 使用静态监听注册

LISTENER =
   (DESCRIPTION_LIST =
     (DESCRIPTION =
        (ADDRESS = (PROTOCOL = TCP)(HOST = SCMPRDDB02)(PORT = 1521))
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)))
   )

ADR_BASE_LISTENER = /u01/app/oracle

4.解决过程

略…

5.参考文档

Duplicate From Active Database Errors : ORA-17629 ORA-17627 ORA-12154 (文档 ID 1144273.1)