11GRAC when using this place name login encounter listening error: ORA-12537TNS: connectionclosed

A group of friends encountered a listening error: ORA-12537: TNS: connectionclosed search found the cause of this error may be: ORA-12537ifListener (includin

A group of friends encountered a listening error: ORA-12537: TNS: connection closed search found the cause of this error may be: ORA-12537 if Listener (includin

A group of friends encountered a listening error: ORA-12537: TNS: connection closed
The cause of this error may be:
ORA-12537 if Listener (including SCAN Listener) and Database are Owned by Different OS User [ID 1069517.1]
That is to say, listeners and databases are different OS users and may encounter the following problems.
The current listener user is GRID, and the database software user is Oracle.
The database is installed under the ORACLE user, and the ORACLE_HOME directory permission setting does not allow the GRID user to operate the ORACLE software.
This error is returned in the following experiment: [grid @ bysrac1 11.2.0] $ su-root
Password:
[Root @ bysrac1 ~] # Cd/u01/app/oracle/product/11.2.0/--- this directory is the home directory of the ORACLE database
[Root @ bysrac1 11.2.0] # ls
Dbhome_1
[Root @ bysrac1 11.2.0] # ls-al
Total 12
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20.
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20 ..
Drwxr-xr-x 75 oracle oinstall 4096 Jun 22 dbhome_1
[Root @ bysrac1 11.2.0] # chmod 700 dbhome_1/
[Root @ bysrac1 11.2.0] # ls-al
Total 12
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20.
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20 ..
Drwx ------ 75 oracle oinstall 4096 Jun 22 dbhome_1
[Root @ bysrac1 11.2.0] # su-oracle
[Oracle @ bysrac1 ~] $ Sqlplus bys/bys @ caiwu
SQL * Plus: Release 11.2.0.1.0 Production on Fri Dec 6 13:24:33 2013
Copyright (c) 1982,200 9, Oracle. All rights reserved.
ERROR:
ORA-12537: TNS: connection closed

Restore the directory permission. SQLPLUS logon is normal:
[Root @ bysrac1 11.2.0] # chmod 755 dbhome_1/
[Root @ bysrac1 11.2.0] # ls-al
Total 12
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20.
Drwxr-xr-x 3 oracle oinstall 4096 Jun 20 ..
Drwxr-xr-x 75 oracle oinstall 4096 Jun 22 dbhome_1
[Root @ bysrac1 ~] # Su-oracle
[Oracle @ bysrac1 ~] $ Sqlplus bys/bys @ caiwu
SQL * Plus: Release 11.2.0.1.0 Production on Fri Dec 6 13:31:59 2013
Copyright (c) 1982,200 9, Oracle. All rights reserved.
Connected:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
BYS @ caiwu> exit

This problem has been solved. It turns out that my colleague skipped an SQL statement and did not execute it, resulting in data inconsistency. Several tables are associated with primary foreign keys.

Related reading:

ORA-01172, ORA-01151 error handling

ORA-00600 [2662] troubleshooting

Troubleshooting for ORA-01078 and LRM-00109

Notes on ORA-00471 Processing Methods

ORA-00314, redolog corruption, or missing Handling Methods

Solution to ORA-00257 archive logs being too large to store

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