今天做Linux下DG配置的时候，遇到一个现象。tnsname.ora文件配置都正常，tnsping也正常，监听也正常。可是仍然报ORA-12514错误：
SQL> set lin 130 pages 130
SQL> select dest_id,error from v$archive_dest;
DEST_ID ERROR
---------- -----------------------------------------------------------------
1
2 ORA-12514: TNS:listener does not currently know of service
requested in connect descriptor
3
4
5
6
7
8
9
10
--查看主库监听
SQL> !lsnrctl status
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:31:46
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=prd)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.5.0 - Production
Start Date 08-OCT-2014 10:34:51
Uptime 0 days 1 hr. 56 min. 54 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=prd)(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 "prd" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
Service "prdXDB" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
Service "prd_XPT" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
The command completed successfully
--tnsnames.ora文件内容
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/10.2.0/db_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)
PRD =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = prd)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = prd)
)
)
STD =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = std)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = prd)
)
)
--主库tnsping測试网络服务名是否正常
SQL> !tnsping prd
TNS Ping Utility for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:32:35
Copyright (c) 1997, 2010, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = prd)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = prd)))
OK (10 msec)
SQL> !tnsping std
TNS Ping Utility for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:32:43
Copyright (c) 1997, 2010, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = std)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = prd)))
OK (20 msec)
--查看备库监听
[oracle@std ~]$ lsnrctl status
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:29:52
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=std)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.5.0 - Production
Start Date 08-OCT-2014 09:41:41
Uptime 0 days 2 hr. 48 min. 11 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=std)(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 "std" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
Service "std_XPT" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
The command completed successfully
--查看备库远程归档路径
SQL> set lin 130 pages 130
SQL> col error for a20
SQL> select dest_id,error,status from v$archive_dest;
DEST_ID ERROR STATUS
---------- -------------------- ---------
1 VALID
2 VALID
3 INACTIVE
4 INACTIVE
5 INACTIVE
6 INACTIVE
7 INACTIVE
8 INACTIVE
9 INACTIVE
10 INACTIVE
11 VALID
--备库tnsping測试网络server名是否正常
SQL> !tnsping prd
TNS Ping Utility for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:39:40
Copyright (c) 1997, 2010, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = prd)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = prd)))
OK (20 msec)
SQL> !tnsping std
TNS Ping Utility for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:39:44
Copyright (c) 1997, 2010, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = std)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = prd)))
OK (10 msec)
tnsping測试下来也都是通的，这就比較奇怪了，可是ORA-12514错误非常明显是指监听方面的问题。导致服务名无法解析，因为主备库採用的是同一个实例名，因此两边的instance_name用的都是prd，乍一看好像非常正常，可是解析确实出现了问题，那么怎么办呢？
之前只不过给server配置了一个动态监听，内容例如以下：
--主库监听listener.ora
# listener.ora Network Configuration File: /u01/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 = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = prd)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
--主库监听listener.ora
# listener.ora Network Configuration File: /u01/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 = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = std)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
能够看到。差别不过主机名不同而已。一个是prd，还有一个是std，静态监听并未配置，即SID_LIST_LISTENER这一项里面的栏目，那么如今为主备库都配置一个监听。
静态监听能够用netmgr配置，这里为了方便，不再进入图形界面运行该命令。而是直接通过改动listener.ora文件来达到目的。其效果是一样的。在原来的listener.ora文件里的SID_LIST_LISTENER中加入例如以下内容（红色部分）：
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = prd)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(SID_NAME = prd)
)
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = std)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
)
注意，加上的内容中。SID_NAME，即instance_name，而GLOBAL_DBNAME，即tnsnames.ora中的SERVICE_NAME，因为tnsnames.ora中的SERVICE_NAME都是prd，因此这里的两个名字是一样的，不会有什么影响，把改动好的文件替换掉原文件。再又一次载入监听文件
SQL> !
[oracle@prd ~]$ lsnrctl reload
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:55:17
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=prd)(PORT=1521)))
The command completed successfully
[oracle@prd ~]$ lsnrctl status
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:55:24
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=prd)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.5.0 - Production
Start Date 08-OCT-2014 10:34:51
Uptime 0 days 2 hr. 20 min. 33 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=prd)(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 "prd" has 2 instance(s).
Instance "prd", status UNKNOWN, has 1 handler(s) for this service...
Instance "prd", status READY, has 1 handler(s) for this service...
Service "prdXDB" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
Service "prd_XPT" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@prd ~]$
注意，这个UNKNOW的prd实例相应的服务名prd就是刚才我们通过静态监听发现的服务名，同那样地，备库也又一次载入监听：
[oracle@std ~]$ lsnrctl reload
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:57:15
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=std)(PORT=1521)))
The command completed successfully
[oracle@std ~]$ lsnrctl status
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 08-OCT-2014 12:57:25
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=std)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 10.2.0.5.0 - Production
Start Date 08-OCT-2014 09:41:41
Uptime 0 days 3 hr. 15 min. 44 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=std)(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 "prd" has 1 instance(s).
Instance "prd", status UNKNOWN, has 1 handler(s) for this service...
Service "std" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
Service "std_XPT" has 1 instance(s).
Instance "prd", status READY, has 1 handler(s) for this service...
The command completed successfully
能够看到。此时备库也多了一个UNKNOWN的，和实例名prd相应的服务prd
--再次查看主库远程归档路径状态
SQL> select dest_id,status,error from v$archive_dest_status;
DEST_ID STATUS ERROR
---------- --------- --------------------
1 VALID
2 VALID
3 INACTIVE
4 INACTIVE
5 INACTIVE
6 INACTIVE
7 INACTIVE
8 INACTIVE
9 INACTIVE
10 INACTIVE
原来dest_id=2的那个远程归档路径的ORA-12514的问题攻克了。此时归档日志就能够通过网路远程传输到备库对应的归档路径中了，再运行redo apply也不会有不论什么问题了。
总结：
这个案例是因为主备库都採用了同一个实例名产生的问题，当我们仅仅配置一个默认的动态监听。会发现主库无法监听到远程备库的相应服务，通过静态监听手动加入上与实例名相应的服务。才干解决问题。
使用静态监听的还有一个优点是，当Oracle数据库实例还没有启动的时候，就会先把相应的服务和实例名。通过静态配置的监听文件给启动起来。而不是等启动实例后由pmon进程再去启动。这样速度更快。不用再等待若干秒，我们的client就能够通过静态监听马上脸上数据库server了。也就是说，能够不依赖server进程，完毕监听的工作。