tnsping命令介绍

什么是tnsping?

可以参考官方文档的具体介绍

http://docs.oracle.com/cd/E11882_01/network.112/e41945/connect.htm#NETAG378

tnsping 实际上就是一个小工具，用来决定是否一个Oracle Net 网络服务（service）可以被接受。

从某种意义上来说，tnsping 针对的 sqlnet连接，就好比为我们常用的ping 命令来检查IP，主机名网络连接情况。

我们来做一个有趣的试验：

先来看看以下配置信息:

数据库所在服务器端：

数据库安装到Linux服务器，hostname = ttdev, IP 地址= 192.168.56.11, ORACLE_SID=ORCL

------

[oracle@ttdev ~]$ cat /home/oracle/app/oracle/product/11.2.0/dbhome_2/network/admin/listener.ora

LISTENER =

  (DESCRIPTION_LIST =

    (DESCRIPTION =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.11)(PORT = 1521))

    )

  )

SID_LIST_LISTENER =

  (SID_LIST =

    (SID_DESC =

      (PROGRAM = extproc)

      (SID_NAME = PLSExtProc)

      (ORACLE_HOME = /home/oracle/app/oracle/product/11.2.0/dbhome_2)

    )

  )

ADR_BASE_LISTENER = /home/oracle/app/oracle/

------

客户端：

在Windows ，安装oracle 客户端后，配置Windows 环境变量 TNS_ADMIN 指向 C:\app\liyang\product\11.2.0\client_2\network\admin

在该路径下，添加 tnsnames.ora 文件

------

TTORCL =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.11)(PORT = 1521))

    )

    (CONNECT_DATA =

      (SERVICE_NAME = orcl)

    )

  )

------

客户端的sqlnet.ora 使用默认

SQLNET.AUTHENTICATION_SERVICES = (NTS)

=============

试验一：

首先，我们来看一下数据库服务器端的实际情况：

通过putty 登录到Linux系统的oracle 用户，停掉数据库，并检查监听情况：

------

[oracle@ttdev ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.1.0.7.0 - Production on Tue Mar 25 18:49:23 2014

Copyright (c) 1982, 2008, Oracle.  All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> quit

Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

[oracle@ttdev ~]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 25-MAR-2014 18:52:03

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.11)(PORT=1521)))

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 11.2.0.2.0 - Production

Start Date                25-MAR-2014 18:14:27

Uptime                    0 days 0 hr. 37 min. 36 sec

Trace Level               off

Security                  ON: Local OS Authentication

SNMP                      OFF

Listener Parameter File   /home/oracle/app/oracle/product/11.2.0/dbhome_2/network/admin/listener.ora

Listener Log File         /home/oracle/app/oracle/diag/tnslsnr/ttdev/listener/alert/log.xml

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.11)(PORT=1521)))

Services Summary...

Service "PLSExtProc" has 1 instance(s).

  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...     《=========服务里面并没有ORCL，因为数据库刚刚被shutdown了！

The command completed successfully

------

在Windows 客户端， 开始 菜单=》 运行 =》 输入 cmd 命令，

进入dos 窗口，并输入 tnsping TTORCL, 返回

------

C:\Users\liyang>tnsping TTORCL

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 10:06:08

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

已使用 TNSNAMES 适配器来解析别名

尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.1   《=====TNSPING 仍然解析成功，返回TTORCL的具体内容！

68.56.11)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = orcl)))

OK (20 毫秒)

------

上面返回的 “尝试连接” 后面部分是sqlnet 如何解析到的TTORCL 别名，或者叫 连接标识符。该别名的解析是通过客户端的 TNS_ADMIN指定路径下的 sqlnet.ora文件中的 NAMES.DIRECTORY_PATH 参数决定的。上面的试验结果显示的是通过 TNSNAMES 适配器 来解析成功的。

该请求可以看到，是通过 TCP 的网络协议  (PROTOCOL = TCP)， 连接到了 IP地址为 192.168.56.11 上的服务器（也可以是主机名），希望连接的端口为 1521, 服务名为  (SERVICE_NAME = orcl)。

连接20毫秒的意思是 一个预估的大概网络传输往返一次的时间。

以上测试说明了，不论数据库是否运行，只要监听存在并在运行，tnsping 都可以成功解析！

=============

试验二：

停止数据库实例，更改监听的端口为 1522 ， 启动监听：

------

[oracle@ttdev admin]$ sqlplus / as sysdba

SQL*Plus: Release 11.1.0.7.0 - Production on Tue Mar 25 21:07:28 2014

Copyright (c) 1982, 2008, Oracle.  All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> quit

Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

[oracle@ttdev admin]$ ps -ef | grep smon

oracle    4335  3326  0 21:08 pts/1    00:00:00 grep smon                  

《====没有数据库实例进程运行

[oracle@ttdev admin]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 25-MAR-2014 21:08:00

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.11)(PORT=1522)))  

《====端口已经更改！

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 11.2.0.2.0 - Production

Start Date                25-MAR-2014 21:01:31

Uptime                    0 days 0 hr. 6 min. 29 sec

Trace Level               off

Security                  ON: Local OS Authentication

SNMP                      OFF

Listener Parameter File   /home/oracle/app/oracle/product/11.2.0/dbhome_2/network/admin/listener.ora

Listener Log File         /home/oracle/app/oracle/diag/tnslsnr/ttdev/listener/alert/log.xml

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.11)(PORT=1522)))   《======监听1522 正常运行

Services Summary...

Service "PLSExtProc" has 1 instance(s).

  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...  《====没有监听到 ORCL的服务

The command completed successfully

------

接下来，回到客户端，执行  tnsping ttorcl

------

C:\Users\liyang>tnsping ttorcl

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 12:09:48

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

已使用 TNSNAMES 适配器来解析别名

尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.1   <===仍然返回成功解析和接受

68.56.11)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = orcl)))

OK (0 毫秒)

------

这个试验二证明了，tnsping 即使在数据库实例停止的情况下，并没有监听1521端口，只要监听运行，tnsping就可以返回正常！

=============

试验三：

那我们再来测试一下，监听停止的情况

------

[oracle@ttdev ~]$ lsnrctl stop

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 25-MAR-2014 19:26:31

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.11)(PORT=1521)))

The command completed successfully

[oracle@ttdev ~]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 25-MAR-2014 19:26:39

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.11)(PORT=1521)))

TNS-12541: TNS:no listener

TNS-12560: TNS:protocol adapter error                                

《=======监听停止

  TNS-00511: No listener

   Linux Error: 111: Connection refused

[oracle@ttdev ~]$ ps -ef | grep smon

oracle    3585  3326  0 19:26 pts/1    00:00:00 grep smon    

《===没有数据库实例启动

------

此时，在客户端再次执行 tnsping:

------

C:\Users\liyang>tnsping TTORCL

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 10:27:55

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

已使用 TNSNAMES 适配器来解析别名

尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.1

68.56.11)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = orcl)))

TNS-12541: TNS: 无监听程序                    <============解析仍然成功，但是报出 TNS-12541 的错误！

------

以上测试说明了，监听停止之后，tnsping 无法被远端监听接受

=============

以下试验四，五开始之前，我们将启动数据库实例和监听

------

[oracle@ttdev admin]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 25-MAR-2014 21:02:31

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.56.11)(PORT=1521)))

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 11.2.0.2.0 - Production

Start Date                25-MAR-2014 21:01:31

Uptime                    0 days 0 hr. 1 min. 0 sec

Trace Level               off

Security                  ON: Local OS Authentication

SNMP                      OFF

Listener Parameter File   /home/oracle/app/oracle/product/11.2.0/dbhome_2/network/admin/listener.ora

Listener Log File         /home/oracle/app/oracle/diag/tnslsnr/ttdev/listener/alert/log.xml

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.11)(PORT=1521)))

Services Summary...

Service "PLSExtProc" has 1 instance(s).

  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...

Service "orcl" has 1 instance(s).

  Instance "orcl", status READY, has 2 handler(s) for this service...

Service "orclXDB" has 1 instance(s).

  Instance "orcl", status READY, has 1 handler(s) for this service...

The command completed successfully

[oracle@ttdev admin]$ ps -ef | grep smon

oracle    4148     1  0 21:01 ?        00:00:00 ora_smon_orcl

oracle    4261  3326  0 21:02 pts/1    00:00:00 grep smon

------

试验四：

删除本地的 tnsnames.ora，之后看一下会出现什么情况

------

C:\Users\liyang>tnsping TTORCL

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 10:31:38

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

TNS-03505: 无法解析名称               《=====================这次，连解析都无法成功！

------

注：编辑tnsnames.ora，如果我将TTORCL 修改为 ORCL，则返回同样的结果

------

C:\Users\liyang>tnsping TTORCL

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 10:33:36

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

TNS-03505: 无法解析名称

------

=============

试验五：

再来测试一个IP地址输入错误的情景

修改tnsnames.ora文件，从192.168.56.11 改为一个不存在的192.168.56.12

------

TTORCL =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.12)(PORT = 1521))  《==更改IP

    )

    (CONNECT_DATA =

      (SERVICE_NAME = orcl)

    )

  )

------

C:\Users\liyang>ping 192.168.56.12

正在 Ping 192.168.56.12 具有 32 字节的数据:

来自 192.168.56.1 的回复: 无法访问目标主机。    <====ping 显示了该IP不存在

C:\Users\liyang>tnsping ttorcl

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 26-3月 -

2014 11:54:25

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:

C:\app\liyang\product\11.2.0\client_2\network\admin\sqlnet.ora

已使用 TNSNAMES 适配器来解析别名

尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.1

68.56.12)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = orcl)))

TNS-12535: TNS: 操作超时            《=======结果是等了较长时间报出超时错误

------

总结：

tnsping 用于诊断各种客户端连接问题还是一个非常好的工具。

但是我们要清楚的知道，这个工具能做什么（检查客户端TNS配置），什么不能做（检查数据库实例是否启动，监听端口是否在1521上）！

从以上试验我们看到，tnsping的解析成功仅仅意味着本地的tnsnames.ora ，IP地址，TNS_ADMIN 变量等配置成功。

但是，完全跟目标数据库实例连接没有任何关系！

最后，sqlnet 跟数据库也完全是独立的两个问题。不要因为sqlnet连接方面出错，就肯定是数据库的问题。要从客户端自身先找原因。
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原文链接：https://blog.csdn.net/lolichan/article/details/84922810