操作环境为Oracle Linux 7.1，Oracle 12.2 RAC数据库，SCAN IP是使用GNS方式创建，在使用SCAN IP登录数据库时出现如下错误
SQL> conn sys/abcd@cs as sysdba
ERROR:
ORA-12545: Connect failed because target host or object does not exist
错误信息直译是目标主机或对象不存在。
查看scan的配置信息状态正常
[grid@cs1 ~]$ srvctl config scan
SCAN name: cs-cluster-scan.cs-cluster.jy.net, Network: 1
Subnet IPv4: 10.10.10.0/255.255.255.0/ens160, dhcp
Subnet IPv6:
SCAN 1 IPv4 VIP: -/scan1-vip/10.10.10.143
SCAN VIP is enabled.
SCAN VIP is individually enabled on nodes:
SCAN VIP is individually disabled on nodes:
SCAN 2 IPv4 VIP: -/scan2-vip/10.10.10.141
SCAN VIP is enabled.
SCAN VIP is individually enabled on nodes:
SCAN VIP is individually disabled on nodes:
SCAN 3 IPv4 VIP: -/scan3-vip/10.10.10.142
SCAN VIP is enabled.
SCAN VIP is individually enabled on nodes:
SCAN VIP is individually disabled on nodes:
查看scan的监听信息状态正常
[grid@cs1 ~]$ srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
Registration invited nodes:
Registration invited subnets:
SCAN Listener is enabled.
SCAN Listener is individually enabled on nodes:
SCAN Listener is individually disabled on nodes:
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
Registration invited nodes:
Registration invited subnets:
SCAN Listener is enabled.
SCAN Listener is individually enabled on nodes:
SCAN Listener is individually disabled on nodes:
SCAN Listener LISTENER_SCAN3 exists. Port: TCP:1521
Registration invited nodes:
Registration invited subnets:
SCAN Listener is enabled.
SCAN Listener is individually enabled on nodes:
SCAN Listener is individually disabled on nodes:
[grid@cs2 ~]$ lsnrctl status LISTENER_SCAN1
LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 13-MAR-2018 11:05:13
Copyright (c) 1991, 2016, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN1)))
STATUS of the LISTENER
------------------------
Alias LISTENER_SCAN1
Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date 12-MAR-2018 19:10:06
Uptime 0 days 15 hr. 55 min. 7 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/product/12.2.0/crs/network/admin/listener.ora
Listener Log File /u01/app/grid/diag/tnslsnr/cs2/listener_scan1/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER_SCAN1)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.10.10.143)(PORT=1521)))
Services Summary...
Service "-MGMTDBXDB" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "66fa07fcd41a56f0e053be828a0abc70" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "_mgmtdb" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "cs" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "csXDB" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "gimr_dscrep_10" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
The command completed successfully
[grid@cs1 ~]$ lsnrctl status LISTENER_SCAN2
LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 13-MAR-2018 11:05:29
Copyright (c) 1991, 2016, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN2)))
STATUS of the LISTENER
------------------------
Alias LISTENER_SCAN2
Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date 12-MAR-2018 19:08:54
Uptime 0 days 15 hr. 56 min. 35 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/product/12.2.0/crs/network/admin/listener.ora
Listener Log File /u01/app/grid/diag/tnslsnr/cs1/listener_scan2/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER_SCAN2)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.10.10.141)(PORT=1521)))
Services Summary...
Service "-MGMTDBXDB" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "66fa07fcd41a56f0e053be828a0abc70" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "_mgmtdb" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "cs" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "csXDB" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "gimr_dscrep_10" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
The command completed successfully
[grid@cs1 ~]$ lsnrctl status LISTENER_SCAN3
LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 13-MAR-2018 11:05:32
Copyright (c) 1991, 2016, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN3)))
STATUS of the LISTENER
------------------------
Alias LISTENER_SCAN3
Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date 12-MAR-2018 19:08:52
Uptime 0 days 15 hr. 56 min. 40 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/product/12.2.0/crs/network/admin/listener.ora
Listener Log File /u01/app/grid/diag/tnslsnr/cs1/listener_scan3/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER_SCAN3)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.10.10.142)(PORT=1521)))
Services Summary...
Service "-MGMTDBXDB" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "66fa07fcd41a56f0e053be828a0abc70" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "_mgmtdb" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
Service "cs" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "csXDB" has 2 instance(s).
Instance "cs1", status READY, has 1 handler(s) for this service...
Instance "cs2", status READY, has 1 handler(s) for this service...
Service "gimr_dscrep_10" has 1 instance(s).
Instance "-MGMTDB", status READY, has 1 handler(s) for this service...
The command completed successfully
在通过SCAN Name来连接RAC数据库时，客户端可以解析所有有完整域名的SCAN Name与VIP Name，但是不能解析没有域名的SCAN Name与VIP Name。通过以下操作可以解决这个问题。
1.在数据库级别使用有完整域名的VIP Name或VIP来设置pfile或spfile文件中的local_listener参数
alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=10.10.10.140)(PORT=1521))))' scope=both sid='cs1';
or
alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=cs1-vip.jy.net)(PORT=1521))))' scope=both sid='cs1';
and
alter system register;
在RAC的每个节点都执行类似上面的操作,但我的环境中local_listener的设置是正确的
SQL> show parameter local_listener
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
local_listener string (DESCRIPTION=(ADDRESS_LIST=(AD
DRESS=(PROTOCOL=TCP)(HOST=10.1
0.10.140)(PORT=1521))))
2.在客户端的hosts文件中增加tnsnames.ora文件中带完整域名的SCAN Name
[root@cs1 ~]# vi /etc/hosts
....
10.10.10.141 cs-cluster-scan.cs-cluster.jy.net
10.10.10.142 cs-cluster-scan.cs-cluster.jy.net
10.10.10.143 cs-cluster-scan.cs-cluster.jy.net
3.再次登录
[oracle@cs11 ~]$ tnsping cs
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 13-MAR-2018 10:40:15
Copyright (c) 1997, 2016, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = cs-cluster-scan.cs-cluster.jy.net)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = cs)))
OK (0 msec)
[oracle@cs1 admin]$ sqlplus /nolog
SQL*Plus: Release 12.2.0.1.0 Production on Tue Mar 13 13:12:32 2018
Copyright (c) 1982, 2016, Oracle. All rights reserved.
SQL> conn sys/abcd@cs as sysdba
Connected.
到此问题解决了，可以使用SCAN Name来登录数据库了。
