动态监听
原网址：http://blog.itpub.net/519536/viewspace-684305/
感受一下Oracle数据库实例的动态监听注册细节。有如下这样一个规律，先总结在这里：
①如果是先启动监听，后启动数据库实例，则动态监听会自动识别到启动的数据库实例；
②在数据库实例正常运行的情况下重启监听，则数据库实例会等很长时间才能在动态监听中注册成功，大约需要1分钟的等待时间；
③如果是先启动数据库实例，后启动监听，效果和②一样；
④如果不希望长时间等待动态监听注册的过程，可以使用“alter system register;”命令加速。
真实的体验一下这个过程。切身体验之后这些结论将显得那样的自然和纯真。
1.第①种场景模拟
1）在数据库实例未启动时启动监听程序
ora11g@secdb /home/oracle$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Tue Jan 18 20:47:22 2011
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
NotConnected@> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:48:58
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 29-DEC-2010 02:03:55
Uptime 20 days 18 hr. 45 min. 3 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
因为数据库实例没有启动，监听理所当然地处于未检测到任何实例的状态。
2）启动数据库实例
NotConnected@> startup;
ORACLE instance started.
Total System Global Area 535662592 bytes
Fixed Size 1337720 bytes
Variable Size 411043464 bytes
Database Buffers 117440512 bytes
Redo Buffers 5840896 bytes
Database mounted.
Database opened.
3）随即查看监听状态
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:49:15
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 29-DEC-2010 02:03:55
Uptime 20 days 18 hr. 45 min. 20 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully
第①种场景结论得到印证：
①如果是先启动监听，后启动数据库实例，则动态监听会自动识别到启动的数据库实例；
2.第②种场景模拟
1）手工停启监听程序
sys@ora11g> !lsnrctl stop
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:52:55
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
The command completed successfully
sys@ora11g> !lsnrctl start
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:03
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Starting /oracle/ora11gR2/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 11.2.0.1.0 - Production
System parameter file is /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
2）每隔一秒检查一下监听的状态
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:11
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 7 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
……省略部分状态检查信息……
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:14
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 11 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
……省略部分状态检查信息……
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:22
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 18 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
……省略部分状态检查信息……
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:58
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 55 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
可见，直到20:53:58时数据库实例仍然没有注册到监听中，此时距离启动监听的时候20:53:03已经过去55秒。
最后是在20:53:59成功完成注册。
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:59
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 20:53:03
Uptime 0 days 0 hr. 0 min. 56 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully
距离启动监听时间56秒，大约用了1分钟的时间才完成数据库实例到监听的动态注册。
第②种场景结论得到印证：
②如果是先启动数据库实例，后启动监听，则数据库实例会等很长时间才能在动态监听中注册成功，大约需要1分钟的等待时间；
3.第③种场景和第②种场景式样的，不赘述。
4.第④种场景模拟
模拟这个场景比较简单，只需要连续执行如下这几条命令即可。
!lsnrctl stop
!lsnrctl start
!lsnrctl status
alter system register;
!lsnrctl status
以下是连续执行后的结果。
1）停止监听程序
sys@ora11g> !lsnrctl stop
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:40
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
The command completed successfully
2）启动监听程序
sys@ora11g> !lsnrctl start
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Starting /oracle/ora11gR2/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 11.2.0.1.0 - Production
System parameter file is /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 21:30:44
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
3）查看监听状态
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 21:30:44
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully
此时，监听未检测到数据库实例信息。
4）手工强制将数据库实例注册到监听
sys@ora11g> alter system register;
System altered.
5）最后确认监听状态
sys@ora11g> !lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44
Copyright (c) 1991, 2009, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date 18-JAN-2011 21:30:44
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully
通过手工注册数据库实例的方法，立杆见影，实例旋即注册到了监听程序中。
第④种场景结论得到印证：
④如果不希望长时间等待动态监听注册的过程，可以使用“alter system register;”命令加速。
5.小结
如果您能将这个过程“躬亲”一下，也许会有这种很美妙的感觉：一切都是那样的自然而和谐。
再次将有关动态监听的结论附在这里：
①如果是先启动监听，后启动数据库实例，则动态监听会自动识别到启动的数据库实例；
②在数据库实例正常运行的情况下重启监听，则实例会等很长时间才能在动态监听中注册成功，大约需要1分钟的等待时间；
③如果是先启动数据库实例，后启动监听，效果和②一样；
④如果不希望长时间等待动态监听注册的过程，可以使用“alter system register;”命令加速。
Good luck.
secooler
11.01.18
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