前提知识

• 客户端连接RAC的TNS串使用多IP方式连接，会默认先连接IP1，若IP1无法连接时，才会连接IP2，以此类推
  参考试验 http://www.821121.com/?p=2042不同连接串配置产生的效果
• 当主库为集群环境并配置有本节点静态监听时，若IP1所在集群环境的数据库关闭（不关闭监听、集群服务），客户端连接IP1会受到静态监听影响，不会尝试后续IP2，从而造成连接异常
• 此次模拟试验时在上述前提下模拟该连接串配置对ADG的影响

环境介绍

主从情况

从库143的tnsnames.ora

89orcl19c =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.85)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.86)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

orcl19cdg2 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.143)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl19cdg2)
    )
)

85监听情况

[grid@rac1 ~]$ lsnrctl status

LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 10-DEC-2024 11:22:48

Copyright (c) 1991, 2019, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date                09-DEC-2024 17:27:51
Uptime                    0 days 17 hr. 54 min. 56 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/19.3.0/grid/network/admin/listener.ora
Listener Log File         /u01/app/grid/diag/tnslsnr/rac1/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.0.85)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.0.87)(PORT=1521)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "+ASM_ARCH" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "+ASM_DATA" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "+ASM_OCR" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "+ASM_TEST" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "24821e337619f56ee0635600a8c08e13" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "266aeef7edadba24e0635500a8c080e0" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "86b637b62fdf7a65e053f706e80a27ca" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "orcl" has 2 instance(s).
  Instance "orcl1", status UNKNOWN, has 1 handler(s) for this service...
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "orclXDB" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "pdb" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
Service "testpdb" has 1 instance(s).
  Instance "orcl1", status READY, has 1 handler(s) for this service...
The command completed successfully

86监听情况(略)

模拟步骤（因博客篇幅有限，日志或文件记录过长，改为省略不展示)

实验一、ADG正常情况下，85关闭，同步是否正常

85节点切集群日志并关库

85实例日志(略)

检查Asm里的归档文件(略)

从库143实例日志情况(略)

从库143归档目录情况(略)

85停库情况下86切日志(略)

从库143实例日志情况(略)

从库143归档情况(略)

结论

可正常同步

实验二、ADG异常，85关闭，86切换日志，从库143重新开启后同步是否正常

86实例日志(略)

86日志显示，连接断开，后续归档没能自动传给从库143，每300秒尝试连接从库143

从库143日志(略)

结论

受监听影响，从库143重新开库并开启同步是无法主动获取到归档的，需要主库进程恢复连接（默认300秒轮询）后主动发送给从库143

实验三、再实验二的基础上修改连接串为scanIP

从库143的tnsnames.ora

89orcl19c =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.89)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

orcl19cdg2 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.143)(PORT = 1521))
    )

结论

若从库143连接串改为连接SCANIP ，从库143开库就能主动连接上86，不用等待300秒的主库轮询