ORA-12537: TNS:connection closed

http://www.vitalsofttech.com/ora-12537-tnsconnection-closed/

Question: When trying to establish a sqlplus connection to the database, I get the “ORA-12537: TNS:connection closed” error message. How do I resolve this?

SQL> conn vst_server/xxx@node1

ERROR:

ORA-12537: TNS connection closed

In the listener log I see this message.

TNS-12518: TNS:listener could not hand off client connection

TNS-12560: TNS:protocol adapter error

TNS-00517: Lost contact

TNS-12547: TNS:lost contact

Answer: According to the oerr utility the ORA error could be due to:

12537, 00000, “TNS:connection closed”

“End of file” condition has been reached; partner has disconnected.

This error could be due to a multiple of reasons.

Reason 1
In a RAC environment for a database which was migrated to a RAC instance, the REMOTE_LISTENER is incorrectly set.

During failover of a service which is configured to use TAF, the connections connected to this service will hang. After the timeout you will get the ORA-12537 error before disconnection.

You will also find more details in the SCAN listener log.

To verify and correct this, first find the RAC cluster name.

dbtest>cemutlo -n

db1-clust

Then verify the REMOTE_LISTENER value in the Database.

sqlplus> show parameter REMOTE_LISTENER

dbtest:1521

Here the REMOTE_LISTENER is incorrectly set to the hostname instead of the cluster name. Correct this value to use the cluster SCAN name.

alter system set REMOTE_LISTENER=’db1-clust:1521′ scope=both sid=dbtest1′;

The session should now failover without disconnecting.

Reason 2
If the VIP name is being used for the LOCAL_LISTENER then the Fully Qualified Network Name (FQDN) should be used. Alternatively the VIP IP can be used instead. See Oracle Metalink Doc ID 970619.1

SQL> alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=dbtest.vst.com)(PORT=1521))))’ service_name=’EQ2′;

or

SQL> alter system set local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=111.21.32.12)(PORT=1521))))’ service_name=’EQ2′;

Reason 3
The Listener process can’t access Oracle binaries in the Database home. The Grid home is installed as a different user than the owner of the Oracle Database binaries. You may find more details in the SCAN listener log for this issue as well.

As the owner of the listener process verify that Oracle Database Binary home can be accessed from the listener home.

ls -l $ORACLE_HOME/bin/oracle

Reason 4
If the home was cloned or moved at the OS level the Oracle Home binaries need to be relinked.

http://feed.askmaclean.com/archives/ora-12537-tnsconnection-closed.html

[oravisR1213@prcsgiapp1 VISR1213_prcsgiapp1]$ sqlplus apps/apps@VISR1213

SQL*Plus: Release 11.1.0.7.0 - Production on Wed Jan 4 11:53:00 2017

Copyright (c) 1982, 2008, Oracle. All rights reserved.

ERROR:
ORA-12537: TNS:connection closed

Enter user-name:
ERROR:
ORA-01017: invalid username/password; logon denied

listener.log的日志如下：

24-JUN-2013 06:21:24 * (CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=lunar)(CID=(PROGRAM=sqlplus)(HOST=lunar1)(USER=oracle))) * (ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.81)(PORT=48962)) * establish * lunar * 12518
TNS-12518: TNS:listener could not hand off client connection
 TNS-12547: TNS:lost contact
  TNS-12560: TNS:protocol adapter error
   TNS-00517: Lost contact
    Linux Error: 32: Broken pipe

这个报错，只解决上应该跟OS的什么配置有关系，但是不清楚哪里的配置问题。
正常的系统，使用strace跟踪，相关log如下：

。。。。。。。。。。。。。。。。。
16123      0.001337 open("/etc/hosts", O_RDONLY) = 10
16123      0.001629 fcntl(10, F_GETFD)  = 0
16123      0.001044 fcntl(10, F_SETFD, FD_CLOEXEC) = 0
16123      0.001640 fstat(10, {st_mode=S_IFREG|0644, st_size=590, ...}) = 0
16123      0.000826 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f11f0d1c000
16123      0.001343 read(10, "# Do not remove the following li"..., 4096) = 590
16123      0.001433 close(10)           = 0
16123      0.001342 munmap(0x7f11f0d1c000, 4096) = 0
16123      0.001008 open("/etc/hostid", O_RDONLY) = -1 ENOENT (No such file or directory)
16123      0.000998 uname({sys="Linux", node="lunar1", ...}) = 0
16123      0.001304 open("/etc/hosts", O_RDONLY) = 10
16123      0.004079 fcntl(10, F_GETFD)  = 0
16123      0.000199 fcntl(10, F_SETFD, FD_CLOEXEC) = 0
16123      0.000167 fstat(10, {st_mode=S_IFREG|0644, st_size=590, ...}) = 0
16123      0.001394 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f11f0d1c000
16123      0.001537 read(10, "# Do not remove the following li"..., 4096) = 590
16123      0.001640 close(10)           = 0
16123      0.001891 munmap(0x7f11f0d1c000, 4096) = 0
16123      0.001114 gettimeofday({1372028588, 2119}, NULL) = 0
16123      0.000792 write(9, "\3\214\0\0\6\0\0\0\0\0\3s\3\376\377\377\377\377\377\377\377\t\0\0\0!\1\0\0\376\377\377"..., 908) = 908
16123      0.003459 read(9, "\6\315\0\0\6\0\0\0\0\0\10&\0\23\0\0\0\23AUTH_VERSION_S"..., 8208) = 1741
16123      0.005878 open("/u01/app/oracle/product/11.2.0/db_1/rdbms/mesg/oraus.msb", O_RDONLY) = 10
16123      0.001656 fcntl(10, F_SETFD, FD_CLOEXEC) = 0
16123      0.001247 lseek(10, 0, SEEK_SET) = 0
16123      0.001266 read(10, "\25\23\"\1\23\3\t\t\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 256) = 256
16123      0.001189 lseek(10, 512, SEEK_SET) = 512
16123      0.001447 read(10, "l\31\3013\276J\213hv{\316\210\200\227S\3113\373\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 512) = 512
16123      0.002147 lseek(10, 1024, SEEK_SET) = 1024
16123      0.001641 read(10, "\30\0$\0002\0;\0D\0Q\0[\0f\0o\0{\0\210\0\240\0\310\0\321\0\331\0\340\0"..., 512) = 512
16123      0.002218 lseek(10, 55808, SEEK_SET) = 55808
16123      0.000759 read(10, "\10\0e\5\0\0008\0f\5\0\0\232\0g\5\0\0\7\1w\5\0\0Z\1x\5\0\0o\1"..., 512) = 512
16123      0.002017 lseek(10, 512, SEEK_SET) = 512
16123      0.000381 read(10, "l\31\3013\276J\213hv{\316\210\200\227S\3113\373\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 512) = 512
16123      0.001120 lseek(10, 1024, SEEK_SET) = 1024
16123      0.000799 read(10, "\30\0$\0002\0;\0D\0Q\0[\0f\0o\0{\0\210\0\240\0\310\0\321\0\331\0\340\0"..., 512) = 512
16123      0.001908 lseek(10, 56320, SEEK_SET) = 56320
。。。。。。。。。。。。。。。。。。

这个有问题的系统使用strace跟踪，相关log如下：

。。。。。。。。。。。。。。。。。。
11647      0.002544 open("/etc/hosts", O_RDONLY) = 9
11647      0.000358 fcntl(9, F_GETFD)   = 0
11647      0.000122 fcntl(9, F_SETFD, FD_CLOEXEC) = 0
11647      0.000169 fstat(9, {st_mode=S_IFREG|0644, st_size=590, ...}) = 0
11647      0.000120 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f48f89b9000
11647      0.000157 read(9, "# Do not remove the following li"..., 4096) = 590
11647      0.000393 read(9, "", 4096)   = 0
11647      0.000107 close(9)            = 0
11647      0.000155 munmap(0x7f48f89b9000, 4096) = 0
11647      0.000178 open("/etc/hosts", O_RDONLY) = 9
11647      0.000129 fcntl(9, F_GETFD)   = 0
11647      0.000559 fcntl(9, F_SETFD, FD_CLOEXEC) = 0
11647      0.000204 fstat(9, {st_mode=S_IFREG|0644, st_size=590, ...}) = 0
11647      0.001389 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f48f89b9000
11647      0.000577 read(9, "# Do not remove the following li"..., 4096) = 590
11647      0.000127 close(9)            = 0
11647      0.000123 munmap(0x7f48f89b9000, 4096) = 0
11647      0.000300 lstat("/u01/app/oracle/diag/clients/user_oracle/host_918442181_80/alert/log.xml", {st_mode=S_IFREG|0640, st_size=132505, ...}) = 0
。。。。。。。。。。。。

上述较大的不同在于fcntl(9, F_GETFD)相关的内容，这个东西我也不懂，c语言都还给老师了…… ：（

于是查询官方文档，根据MOS介绍，逐一核对文件权限：

检查oracle用户的权限：
1，grid的是正确的：

[grid@lunar1 trace]$ ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 grid asmadmin 203973009 May  3 12:42 /u01/11.2.0/grid/bin/oracle
[grid@lunar1 trace]$

oracle的是错误的：

[oracle@lunar1 ~]$ ls -l $ORACLE_HOME/bin/oracle
-rwxr-s--x 1 oracle asmadmin 232399431 May  3 15:11 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[oracle@lunar1 ~]$

使用root修改

[root@lunar1 ~]# chmod 6751 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[root@lunar1 ~]#

再次检查已经正确了：

[oracle@lunar1 ~]$ ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 oracle asmadmin 232399431 May  3 15:11 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[oracle@lunar1 ~]$

2，oracle用户的ORACLE_HOME所在文件系统不支持setuid/suid（ 也不支持 nosetuid/nosuid 设置），例如:

mount| grep <mount_point_of_ORACLE_HOME>
/home/oracle on /dev/dsk/diskoracle read/write/nosuid..

我这里正常的：

[oracle@lunar1 ~]$ mount| grep /u01
/dev/sdb1 on /u01 type ext3 (rw)
[oracle@lunar1 ~]$

再次测试还是连接不上：

SQL> conn sys/oracle@lunar as sysdba
ERROR:
ORA-12537: TNS:connection closed

Warning: You are no longer connected to ORACLE.
SQL>

3，检查oracle用户的$ORACLE_HOME应该为755（注意，不要带 -R ！！！）：

[oracle@lunar1 ~]$ chmod 755 $ORACLE_HOME
[oracle@lunar1 ~]$

这次可以了：

SQL> conn sys/oracle@lunar as sysdba
Connected.
SQL>

把节点2也修改了：

[oracle@RAC2 ~]$ chmod 755 $ORACLE_HOME
[oracle@RAC2 ~]$ 

[oracle@RAC2 ~]$ ls -l $ORACLE_HOME/bin/oracle
-rwxr-s--x 1 oracle asmadmin 232399431 May  3 15:16 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[oracle@RAC2 ~]$ exit
logout
[root@RAC2 ~]# chmod 6751 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[root@RAC2 ~]# su - oracle
[oracle@RAC2 ~]$ ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 oracle asmadmin 232399431 May  3 15:16 /u01/app/oracle/product/11.2.0/db_1/bin/oracle
[oracle@RAC2 ~]$ 

[grid@RAC2 ~]$ ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 grid oinstall 203973009 May  3 12:46 /u01/11.2.0/grid/bin/oracle
[grid@RAC2 ~]$