Instance "orcl",status UNKNowN,has 1 handler(s) for this service...，有需要的朋友可以参考下。
今天将服务器的监听程序重启了一下，重启后成功，但是数据库死活注册不上去，导致客户端没法连接到数据库：
<span style="font-family: Arial,Helvetica,sans-serif;">-- 启动监听 [oracle@localhost dbs]$ lsnrctl start</span>
LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 04-FEB-2015 13:43:40 copyright (c) 1991,2011,Oracle. All rights reserved. TNS-01106: Listener using listener name LISTENER has already been started [oracle@localhost dbs]$ lsnrctl status LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 04-FEB-2015 13:43:45 copyright (c) 1991,Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production Start Date 04-FEB-2015 13:43:21 Uptime 0 days 0 hr. 0 min. 23 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /u01/app/oracle/network/admin/listener.ora Listener Log File /u01/app/diag/tnslsnr/localhost/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.3.100)(PORT=1521))) Services Summary... Service "CLRExtProc" has 1 instance(s). Instance "CLRExtProc",has 1 handler(s) for this service... Service "orcl" has 1 instance(s). Instance "orcl",has 1 handler(s) for this service... The command completed successfully启动后，提示 Instance "orcl",has 1 handler(s) for this service... 这个提示一般认为很正常，是由于实例没有注册到监听服务中去，于是注册实例
sql> alter system register; System altered.
实例已经注册，再来看看监听状态：
[oracle@localhost dbs]$ lsnrctl start LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 04-FEB-2015 13:43:40 copyright (c) 1991,has 1 handler(s) for this service... The command completed successfully
发现orcl 还是未知状态（ ），查看监听配置是否有问题
--监听文件的内容 [oracle@localhost admin]$ pwd /u01/app/oracle/network/admin [oracle@localhost admin]$ more listener.ora # listener.ora Network Configuration File: /u01/app/oracle/network/admin/listener.ora # Generated by Oracle configuration tools. SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (SID_NAME = CLRExtProc) (ORACLE_HOME = /u01/app/oracle) (PROGRAM = extproc) ) (SID_DESC = (GLOBAL_dbnAME = orcl) (ORACLE_HOME = /u01/app/oracle) (SID_NAME = orcl) ) ) LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)) (ADDRESS = (PROTOCOL = TCP)(HOST =192.168.3.100)(PORT = 1521)) ) ) ADR_BASE_LISTENER = /u01/app
监听文件貌似没有问题，因为我之前是没有问题，看看前面监听的日志：
[oracle@localhost admin]$ tail -30 /u01/app/diag/tnslsnr/localhost/listener/alert/log.xml <msg time='2015-02-04T13:43:21.139+08:00' org_id='oracle' comp_id='tnslsnr' type='UNKNowN' level='16' host_id='localhost.localdomain' host_addr='::1'> <txt>WARNING: Subscription for node down event still pending </txt> </msg> <msg time='2015-02-04T13:43:21.140+08:00' org_id='oracle' comp_id='tnslsnr' type='UNKNowN' level='16' host_id='localhost.localdomain' host_addr='::1'> <txt>04-FEB-2015 13:43:21 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=localhost.localdomain)(USER=oracle))(COMMAND=status)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=186647296)) * status * 0 </txt> </msg> <msg time='2015-02-04T13:43:40.091+08:00' org_id='oracle' comp_id='tnslsnr' type='UNKNowN' level='16' host_id='localhost.localdomain' host_addr='::1'> <txt>04-FEB-2015 13:43:40 * ping * 0 </txt> </msg> <msg time='2015-02-04T13:43:45.083+08:00' org_id='oracle' comp_id='tnslsnr' type='UNKNowN' level='16' host_id='localhost.localdomain' host_addr='::1'> <txt>WARNING: Subscription for node down event still pending </txt> </msg> <msg time='2015-02-04T13:43:45.084+08:00' org_id='oracle' comp_id='tnslsnr' type='UNKNowN' level='16' host_id='localhost.localdomain' host_addr='::1'> <txt>04-FEB-2015 13:43:45 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=localhost.localdomain)(USER=oracle))(COMMAND=status)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=186647296)) * status * 0 </txt> 发现监听在启动时，读取了主机名： localhost.localdomain ，个人感觉应该是主机名解析有问题，于是看看hosts文件
[root@localhost oracle]# hostname localhost.localdomain [root@localhost oracle]# more /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.3.100 localhost.localdomain 发现三个IP都对应了机器名localhost.localdomain ，可能这种情况导致监听无法解析导致数据库不能注册到监听程序中
[root@localhost oracle]# more /etc/hosts #127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 172.0.0.1 localhost 192.168.3.100 localhost.localdomain #::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
然后再重启监听程序
[oracle@localhost dbs]$ lsnrctl LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 04-FEB-2015 15:10:10 copyright (c) 1991,Oracle. All rights reserved. Welcome to LSNRCTL,type "help" for information. LSNRCTL> stop Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))) The command completed successfully LSNRCTL> start Starting /u01/app/oracle/bin/tnslsnr: please wait... TNSLSNR for Linux: Version 11.2.0.3.0 - Production System parameter file is /u01/app/oracle/network/admin/listener.ora Log messages written to /u01/app/diag/tnslsnr/localhost/listener/alert/log.xml Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.3.100)(PORT=1521))) Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production Start Date 04-FEB-2015 15:10:29 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/network/admin/listener.ora Listener Log File /u01/app/diag/tnslsnr/localhost/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.3.100)(PORT=1521))) Services Summary... Service "CLRExtProc" has 1 instance(s). Instance "CLRExtProc",has 1 handler(s) for this service... The command completed successfully LSNRCTL>
实例注册后，再看看监听状态
LSNRCTL> status Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production Start Date 04-FEB-2015 15:10:29 Uptime 0 days 0 hr. 1 min. 29 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /u01/app/oracle/network/admin/listener.ora Listener Log File /u01/app/diag/tnslsnr/localhost/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.3.100)(PORT=1521))) Services Summary... Service "CLRExtProc" has 1 instance(s). Instance "CLRExtProc",has 1 handler(s) for this service... Service "orcl.localdomain" has 1 instance(s). Instance "orcl",status READY,has 1 handler(s) for this service... Service "orcl11gXDB.localdomain" has 1 instance(s). Instance "orcl",sans-serif; font-size:14px"> 发现实例已经处于ready状态了。
OK，到此，客户端已经可以连接到数据库了
