今天碰到這個問題  問同事 被jj了  感覺自己技術太Low了  最後厚臉皮問了搞定了。

在檢視oracle監聽狀態的時候，會出現下面資訊

[[email protected] ~]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 04-DEC-2017 19:09:43

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle11g)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date                04-DEC-2017 19:09:40
Uptime                    0 days 0 hr. 0 min. 3 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/oracle11g/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle11g)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
The listener supports no services
The command completed successfully

The listener supports no services

這個問題怎麼解決

首先關閉防火牆  因為防火牆可能關閉了1521埠

[[email protected] ~]# service iptables stop

[[email protected] ~]# chkconfig iptables off

之後去檢視listen.ora裡面有沒有資料庫資訊，因為監聽裡面就是要儲存資料庫資訊的。

[[email protected] ~]$ cd /u01/app/oracle/product/11.2.0/db_1/network/admin/
[[email protected]

# listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

#LISTENER =
 # (DESCRIPTION_LIST =
  #  (DESCRIPTION =
   #   (ADDRESS = (PROTOCOL = TCP)(HOST = oracle11g)(PORT = 1521))
    #  (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    #)
 # )

ordb =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.100)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ordb)
    )
  )

ADR_BASE_LISTENER = /u01/app/oracle

#註釋了通過netca建立資料庫預設寫進listen.ora裡面的內容，加上了

ordb =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.100)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ordb)
    )
  )

裡面描述了資料庫的詳細資訊，這樣通過客戶端通過監聽可以連線到資料庫例項，例項分配server process來服務客戶端。

修改配置檔案之後關閉重啟
[[email protected] admin]$ lsnrctl stop

[[email protected] admin]$ lsnrctl start

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 04-DEC-2017 19:15:02

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

TNS-01106: Listener using listener name LISTENER has already been started
[[email protected] admin]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 04-DEC-2017 19:15:10

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date                04-DEC-2017 19:14:26
Uptime                    0 days 0 hr. 0 min. 44 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/oracle11g/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle11g)(PORT=1521)))
Services Summary...
Service "oradb" has 1 instance(s).
  Instance "ordb", status READY, has 1 handler(s) for this service...
The command completed successfully
可以看到沒有了之前的The listener supports no services資訊了

因為資料庫將例項註冊到監聽是每分鐘註冊，即不會立刻註冊，要想馬上將例項註冊到監聽就要在資料庫啟動狀態下使用

SQL> alter system register;

這樣監將例項註冊到監聽了就可以遠端連線資料庫了，而不是在本地sqlplus通過sqlplus / as sysdba來連線了。