【故障处理】【LISTENER】主机名修改为IP地址后LISTENER无法监听到实例

1.【环境信息】
操作系统
ora10g@testdb /home/oracle$ uname -a
Linux testdb 2.6.18-53.el5xen #1 SMP Wed Oct 10 16:48:44 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux
数据库
sys@ora10g> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bi
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

2.【问题现象】
一句话描述：将listener.ora和tnsnames.ora文件中的HOST信息从原来的主机名字修改为IP地址后，监听可以启动，但是无论如何也监听不到数据库实例的信息（即使反复重启数据库）。

问题展开描述：
修改前的listener.ora内容如下：
ora10g@testdb /oracle/app/oracle/product/10.2.0/db_1/network/admin$ cat listener.ora
# listener.ora Network Configuration File: /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /oracle/app/oracle/product/10.2.0/db_1)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = testdb)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )

修改后的listener.ora内容如下：
ora10g@testdb /oracle/app/oracle/product/10.2.0/db_1/network/admin$ cat listener.ora
# listener.ora Network Configuration File: /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /oracle/app/oracle/product/10.2.0/db_1)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 144.194.192.183)(PORT = 1521)(IP = FIRST))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )

对应的tnsnames.ora文件中也同样的将主机名testdb修改为IP地址144.194.192.183。

修改后重新启动监听，但是监听一直保持在如下的状态
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=144.194.192.183)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                21-JUL-2009 14:34:20
Uptime                    0 days 0 hr. 0 min. 36 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=144.194.192.183)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

就是监听不到对应的数据库实例信息！！！！！

3.【问题原因】
罪魁祸首在/etc/hosts文件！！
先看一下在我处理之前该文件的内容：
[root@testdb ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1   testdb  localhost.localdomain   localhost
::1     localhost6.localdomain6 localhost6

先提示到这里，停一停，想一想，这到底是为什么呢？如果您也遇到了这个问题，处理思路是什么呢？

思考ing ……

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好了，不卖关子了，问题出在，在这种默认配置下（操作系统安装后的状态），主机名字和本机的IP地址没有对应起来.
换一种好理解的方式讲，在这种情况下如果您ping主机名testdb的话：
ora10g@testdb /home/oracle$ ping testdb
PING testdb (127.0.0.1) 56(84) bytes of data.
64 bytes from testdb (127.0.0.1): icmp_seq=1 ttl=64 time=0.076 ms
64 bytes from testdb (127.0.0.1): icmp_seq=2 ttl=64 time=0.052 ms
64 bytes from testdb (127.0.0.1): icmp_seq=3 ttl=64 time=0.053 ms

结果是主机名testdb直接对应到了127.0.0.1地址，没有对应到正确的144.194.192.183地址！！

4.【问题解决】
（1）将/etc/hosts内容修改为：
[root@testdb ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1       localhost.localdomain   localhost
::1     localhost6.localdomain6 localhost6
144.194.192.183   testdb

比较一下与之前文件的不同，这里修改的内容如下：
1）将127.0.0.1后面的testdb主机名删除
2）添加IP地址和主机名对应关系144.194.192.183   testdb

通过ping主机名testdb的方式验证一下修改后的效果：
ora10g@testdb /home/oracle$ ping testdb
PING testdb (144.194.192.183) 56(84) bytes of data.
64 bytes from testdb (144.194.192.183): icmp_seq=1 ttl=64 time=0.082 ms
64 bytes from testdb (144.194.192.183): icmp_seq=2 ttl=64 time=0.047 ms
64 bytes from testdb (144.194.192.183): icmp_seq=3 ttl=64 time=0.050 ms
到此，主机名testdb与IP地址 144.194.192.183建立起了对应关系。

（2）重新启动监听
LSNRCTL> stop
LSNRCTL> start
Starting /oracle/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 10.2.0.1.0 - Production
System parameter file is /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /oracle/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=144.194.192.183)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=144.194.192.183)(PORT=1521)(IP=FIRST)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                21-JUL-2009 15:05:08
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=144.194.192.183)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL>

过大概半分钟的样子，LISTENER即可监听到数据库的实例ora10g：
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=144.194.192.183)(PORT=1521)(IP=FIRST)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                21-JUL-2009 15:05:08
Uptime                    0 days 0 hr. 0 min. 36 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=144.194.192.183)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "ora10g" has 1 instance(s).
  Instance "ora10g", status READY, has 1 handler(s) for this service...
Service "ora10g_XPT" has 1 instance(s).
  Instance "ora10g", status READY, has 1 handler(s) for this service...
The command completed successfully

5.总结
数据库的任何修改都是存在风险的，即使您“觉得”没有问题，永远记得“墨菲定律”--Anything that can go wrong will go wrong!
（1）任何事都没有表面看起来那么简单；
（2）所有的事都会比你预计的时间长；
（3）会出错的事总会出错；
（4）如果你担心某种情况发生，那么它就更有可能发生。
所以，在做任何事情之前都要充分的测试，否则就有可能被“墨菲”到！

-- The End --

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转载于:http://blog.itpub.net/519536/viewspace-609799/