c#连接oracle数据库报“ORA-12154: TNS: 无法解析指定的连接标识符”错误，怎么解决？

Posted 2023-05-03

连接串是：Data Source=HSCN;user=user;password=password

tnsnames.ora里的配置是：
HSCN.HSCNCREDIT.CN =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.20.15.1)(PORT =1521))
)
(CONNECT_DATA =
(SID = HSCN)
(SERVER = DEDICATED)
)
)

sqlplus 可以连接成功，但是在asp.net程序中就报标题的错误

Data Source=HSCN是指你的本地tnsname，所以他应该等于tnsname.ora文件里参数的第一个等号前的字符，就是这里的 HSCN.HSCNCREDIT.CN
改成HSCN 参考技术A (SID = HSCN)

你的Data Source=HSCN不一定是这里的SID，你检查一下，或者问问

oracle数据库报错ORA-27300 ORA-27301等错误

oracle数据库日志报错ORA-27300 ORA-27301 ORA-27302 ORA-27157处理记录：

1、事件的原因排查

应用连接数据库失败，先连接数据库服务器，启动数据库服务恢复应用业务，然后排查数据库crush原因：
1）查看messages日志是否有与Oracle用户相关的出错信息

# cat /etc/redhat-release 
CentOS Linux release 7.2.1511 (Core)
# cat /var/log/messages |grep failed

2）查看用户邮件日志是否有与Oracle用户相关的出错信息

# tail -n 200 /var/mail/oracle

3）检查跟踪日志文件

SQL> select value from v$diag_info where name =‘Diag Trace‘;
VALUE
--------------------------------
/app/oracle/diag/rdbms/crm/crm/trace

$ cat /app/oracle/diag/rdbms/crm/crm/trace/alert_crm.log |grep ORA-
$ cat /app/oracle/diag/rdbms/crm/crm/trace/alert_crm.log |grep err
$ cat /app/oracle/diag/rdbms/crm/crm/trace/alert_crm.log |grep fail 

SQL> select name,value from v$diag_info;
NAME              VALUE
--------------------------------
Diag Enabled    TRUE
ADR Base    /app/oracle/
ADR Home    /app/oracle/diag/rdbms/crm/crm
Diag Trace  /app/oracle/diag/rdbms/crm/crm/trace
Diag Alert  /app/oracle/diag/rdbms/crm/crm/alert
Diag Incident   /app/oracle/diag/rdbms/crm/crm/incident
Diag Cdump  /app/oracle/diag/rdbms/crm/crm/cdump
Health Monitor  /app/oracle/diag/rdbms/crm/crm/hm
Default Trace File  /app/oracle/diag/rdbms/crm/crm/trace/crm_ora_10974.trc
Active Problem Count    1
Active Incident Count   1

查看log.xml搜索问题出现时间点

$ less /app/oracle/diag/rdbms/crm/crm/alert/log.xml
Errors in file /app/oracle/diag/rdbms/crm/crm/trace/crm_dbw2_80900.trc:
ORA-27157: OS post/wait facility removed
ORA-27300: OS system dependent operation:semop failed with status: 43
ORA-27301: OS failure message: Identifier removed
ORA-27302: failure occurred at: sskgpwwait1
Errors in file /app/oracle/diag/rdbms/crm/crm/trace/crm_dbw3_80902.trc:
ORA-27157: OS post/wait facility removed
ORA-27300: OS system dependent operation:semop failed with status: 43
ORA-27301: OS failure message: Identifier removed
ORA-27302: failure occurred at: sskgpwwait1

2、事件的解决处理

This could be due to some outside user or application removing the semaphores/shared memory. 
To monitor the semaphore/shared memory state we can use the following methods:

Setup a cronjob to run every 5-10min and dump the output of ‘ipcs‘ and ‘ps - ef‘ to a file with a timestamp. 
Rotate your logs every 4-7 days to build a history. 
Then if the problem re-occurs, we can at least try to make sure ‘ipcrm‘ wasn‘t the culprit and get some general information of the state of the IPC resources plus the processes running.

You can also consult with your sysadmin to check if there is any OS level auditing that can be turned on to audit the usage of commands like ‘ipcrm‘ which can remove shared memory segments /semaphore sets.

Note: This issue can happen on different platform, but in case you encounter the issue in RHEL7.2, then please also check below RHEL7.2 specific information.

In  RHEL7.2 operating system setting RemoveIPC=YES crashes the database.The default value for RemoveIPC in RHEL7.2 is YES.

         Workaround :

      1) Set RemoveIPC=no in /etc/systemd/logind.conf if it is not in that file

      2) Reboot the server or restart systemd-logind as follows:
       # systemctl daemon-reload
       # systemctl restart systemd-logind

Centos7.2有个特性，默认该配置是为yes

# vim /etc/systemd/logind.conf
RemoveIPC=no
# systemctl daemon-reload
# systemctl restart systemd-logind