今天配置完共享服务器模式之后发现登录过程中报错ORA-12523，排查错误之后发现是静态监听惹的祸。本机之上有两个监听，一个静态监

今天配置完共享服务器模式之后发现登录过程中报错ORA-12523，排查错误之后发现是静态监听惹的祸。

本机之上有两个监听，一个静态监听1521端口，一个动态监听1526端口。

LISTENER=

(DESCRIPTION=

(ADDRESS_LIST=

(ADDRESS=(PROTOCOL=tcp)(HOST=jp)(PORT=1521))

(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))))

LSNR2=

(DESCRIPTION=

(ADDRESS_LIST=

(ADDRESS=(PROTOCOL=tcp)(HOST=jp)(PORT=1526))

(ADDRESS=(PROTOCOL=ipc)(KEY=extproc1))))

trace_level_LSNR2=SUPPORT

SID_LIST_LISTENER=

(SID_LIST=

(SID_DESC=

(GLOBAL_DBNAME=PROD)

(Oracle_HOME=/u01/app/oracle/product/10.2.0/db_1)

(SID_NAME=PROD))

(SID_DESC=

(SID_NAME=plsextproc)

(ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1)

(PROGRAM=extproc)))

出错时的tnsnames配置：

prod_s=

(description =

(address = (protocol = tcp)(host = jp)(port = 1521))

(connect_data =

(server = shared)

(service_name = PROD)

)

)

连接数据库时报错：

[oracle@jp admin]$ sqlplus sys/oracle@prod_s as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Mar 8 10:43:54 2014

Copyright (c) 1982, 2005, Oracle. All rights reserved.

ERROR:

ORA-12523: TNS:listener could not find instance appropriate for the client

connection

检查之后发现prod_s连接串走的是静态监听，共享服务器模式需要将调度进程的信息注册到监听之中，当有连接连入时，监听会选择一个负载最低的调度进程。而静态监听没有调度进程的信息，，导致通过shared_server模式连接报错。

修改tnsnames

prod_s=

(description =

(address = (protocol = tcp)(host = jp)(port = 1526))

(connect_data =

(server = shared)

(service_name = PROD)

)

)

重新通过shared_server连接，成功：

[oracle@jp admin]$ sqlplus sys/oracle@prod_s as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Mar 8 10:42:22 2014

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Connected to:

Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production

With the Partitioning, OLAP and Data Mining options

SYS@prod_s>select server from v$session;

SERVER

---------

SHARED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

SERVER

---------

DEDICATED

DEDICATED

DEDICATED

DEDICATED

DEDICATED

16 rows selected.