how to decision which is current listener
how to decision which is current listener???
最近快被listener搞死了，本以为自己已经很明白了，但是碰到问题的时候，还是无法解释清楚，做了几个实验终于清楚了。
不知道大家是否注意过这样一个问题，当你做HACMP双机互备的时候，为了防止切换回原来节点时，停监听的动作不影响原始库中新连接的会话，所以两个节点的listener端口不能相同。但是我发现
节点A >lsnrctl status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias listener_1521
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:52:49
Uptime 0 days 0 hr. 0 min. 21 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1521.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
The listener supports no services
The command completed successfully
节点B >lsnrctl status
LSNRCTL> status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
问题：这是为什么？节点A1521端口，节点B1522端口，为什么他们的current不一样？那么oracle选择current listener的方法和顺序是什么？？
答案：oracle默认的current_listener为(ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
那么当多个监听名字共用1521这个端口时，current_listener 为最后一次启动的listener，他们都是listener的别名。
问题：多个listener，oracle会认为who是current listener??
结论：有LISTENER参数，无论端口是否为1521，默认的current_listener=listener，与这个listener同端口的只是一个别名而已
无LISTENER参数，找1521端口为current_listener=listener,与这个listener同端口的只是一个别名而已
无LISTENER参数，无1521端口，默认1521端口为current_listener
1. listener.ora文件中有LISTENER参数，端口为1521端口
则：current_listener = listener = listener_1521
e.g.
[oracle@rac1 admin]$ more listener.ora
LISTENER_1522 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1522))
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1521))
)
)
LISTENER_1521 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1521))
)
)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LSNRCTL> start
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1.domain.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 17-JUN-2009 23:42:38
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL> start listener_1521
TNS-01106: Listener using listener name LISTENER has already been started
备注：listener_1521和listener共用一个端口号
如果先启动listener_1521，那么listener_1521是listener的一个别名，那么listener_1521为current_listener
LSNRCTL> start listener_1521
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1521.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1.domain.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias listener_1521(listener_1521是listener的一个别名)
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 17-JUN-2009 23:58:48
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1521.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
The listener supports no services
The command completed successfully
2. listener.ora文件中有LISTENER参数，端口为非1521端口
则：current_listener=listener=listener_1522
e.g.
[oracle@rac1 admin]$ more listener.ora
LISTENER_1522 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1522))
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1522))
)
)
LISTENER_1521 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1521))
)
)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LSNRCTL> start
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1522)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1.domain.com)(PORT=1522)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 17-JUN-2009 23:48:41
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1522)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL> start listener_1522
TNS-01106: Listener using listener name LISTENER has already been started
备注：如果先启动listener_1522，那么listener_1522是listener的一个别名
3. listener.ora文件中没有LISTENER参数，端口为1521端口
则：current_listener=listener=listener_1521
e.g.
[oracle@rac1 admin]$ more listener.ora
LISTENER_1522 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1522))
)
)
LISTENER_1521 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1521))
)
)
SID_LIST_LISTENER_1521 =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LSNRCTL> start
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))/*(本机默认1521端口)*/
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:06:46
Uptime 0 days 0 hr. 0 min. 6 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
The listener supports no services
The command completed successfully
LSNRCTL> status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:06:46
Uptime 0 days 0 hr. 0 min. 9 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
The listener supports no services
The command completed successfully
LSNRCTL> start listener_1521
TNS-01106: Listener using listener name LISTENER has already been started
LSNRCTL> stop
备注：如果先启动listener_1521，那么listener_1521是listener的一个别名
LSNRCTL> start listener_1521
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1521.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1.domain.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias listener_1521
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:08:11
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1521.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
4. listener.ora文件中没有LISTENER参数，端口中没有1521端口
则：current_listener=listener
e.g.
[oracle@rac1 admin]$ more listener.ora
LISTENER_1522 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1522))
)
)
LISTENER_1523 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1523))
)
)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LSNRCTL> start
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:16:04
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
补充，与前面无关
5. 动态注册非1521端口的监听
e.g.
SQL> show parameter listener
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
local_listener string
remote_listener string
SQL> alter system set local_listener='(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.230.66)(PORT=1523))' scope=both sid='devdb1';
System altered.
SQL> show parameter listener
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
local_listener string (ADDRESS=(PROTOCOL=TCP)(HOST=192.168.230.66)(PORT=1523))
remote_listener string
[oracle@rac1 admin]$ more listener.ora
LISTENER_1521 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1521))
)
)
LISTENER_1523 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1.domain.com)(PORT = 1523))
)
)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LSNRCTL> start
Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:26:18
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL> status listener_1523
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac1.domain.com)(PORT=1523)))
STATUS of the LISTENER
------------------------
Alias listener_1523
Version TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date 18-JUN-2009 00:16:28
Uptime 0 days 0 hr. 10 min. 21 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/10.2.0/db_1/network/log/listener_1523.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac1.domain.com)(PORT=1523)))
Services Summary...
Service "devdb" has 1 instance(s). /*动态注册*/
Instance "devdb1", status READY, has 1 handler(s) for this service...
Service "devdbXDB" has 1 instance(s).
Instance "devdb1", status READY, has 1 handler(s) for this service...
Service "devdb_XPT" has 1 instance(s).
Instance "devdb1", status READY, has 1 handler(s) for this service...
The command completed successfully
参考文献：
1. listener的静态注册与动态注册详述
http://space.itpub.net/9252210/viewspace-580699
2. TNS-01106:Listener using listener name already been started
http://space.itpub.net/9252210/viewspace-606635
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/9252210/viewspace-606650/ ，如需转载，请注明出处，否则将追究法律责任。
