TNS-12542: TNS:address already in use Linux Error: 98

Problem Description
After changing listener entry while you start the oracle listener it fails with error TNS-12542 like below.

[grid@DC-DB-01 ~]$ lsnrctl start listener2

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 19-SEP-2010 11:41:48

Copyright (c) 1991, 2009, Oracle.  All rights reserved.

Starting /u01/app/11.2.0/grid/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.1.0 - Production
System parameter file is /u01/app/11.2.0/grid/network/admin/listener.ora
Log messages written to /u01/app/11.2.0/grid/log/diag/tnslsnr/DC-DB-01/listener2/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER2)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=DC-DB-01)(PORT=1522)))
Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=DC-DB-01-vip)(PORT=1522)))
TNS-12542: TNS:address already in use
TNS-12560: TNS:protocol adapter error
TNS-00512: Address already in use
Linux Error: 98: Address already in use

Listener failed to start. See the error message(s) above...

The XML log file shows following message.

<msg time='2010-09-19T11:42:38.026+06:00' org_id='oracle' comp_id='tnslsnr'
 type='UNKNOWN' level='16' host_id='DC-DB-01'
 host_addr='192.168.100.101'>
<txt>Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=DC-DB-01-vip)(PORT=1522)))
</txt>
</msg>
<msg time='2010-09-19T11:42:38.026+06:00' org_id='oracle' comp_id='tnslsnr'
 type='UNKNOWN' level='16' host_id='DC-DB-01'
 host_addr='192.168.100.101'>
<txt>TNS-12542: TNS:address already in use
TNS-12560: TNS:protocol adapter error
TNS-00512: Address already in use
Linux Error: 98: Address already in use
</txt>
</msg>
<msg time='2010-09-19T11:42:38.027+06:00' org_id='oracle' comp_id='tnslsnr'
 type='UNKNOWN' level='16' host_id='DC-DB-01'
 host_addr='192.168.100.101'>
<txt>No longer listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER2)))
</txt>
</msg>
<msg time='2010-09-19T11:42:38.027+06:00' org_id='oracle' comp_id='tnslsnr'
 type='UNKNOWN' level='16' host_id='DC-DB-01'
 host_addr='192.168.100.101'>
<txt>No longer listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=DC-DB-01)(PORT=1522)))
</txt>
</msg>

Here goes listener.ora file contents.

LISTENER2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = LISTENER2))
      (ADDRESS = (PROTOCOL = TCP)(HOST =DC-DB-01)(PORT = 1522))
      (ADDRESS = (PROTOCOL = TCP)(HOST =DC-DB-01-vip)(PORT = 1522))      
    )
  ) 

Cause of the Problem
The "TNS-00512: Address already in use" is occurred as there is duplicate port used in same listener2 entry. It is not possible to start a listener using duplicate TCP port or IPC KEY values in a single listener.ora file configuration.

Solution of the Problem
The solution is edit the listener entry so that there does exist duplicate listener TCP port or IPC key. You can either change the port or IPC key or remove the duplicate entry. So either of the following two entries are valid.

LISTENER2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = LISTENER2))
      (ADDRESS = (PROTOCOL = TCP)(HOST =DC-DB-01)(PORT = 1522))
  
    )
  ) 

or,

LISTENER2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = LISTENER2))
      (ADDRESS = (PROTOCOL = TCP)(HOST =DC-DB-01)(PORT = 1522))
      (ADDRESS = (PROTOCOL = TCP)(HOST =DC-DB-01-vip)(PORT = 1523))      
    )
  ) 

General Solutions of ORA-12547: TNS: lost contact

In the post Troubleshoot ORA-12547: TNS: lost contact it is already discussed about the specific causes and solutions of ORA-12547: TNS: lost contact. If you don't have those specific scenarios then this post will provide you general solutions for error ORA-12547 which might help you to avoid this error.

1. Verify that environmental variable ORACLE_HOME, ORACLE_SID, PATH, LD_LIBRARY_PATH are correct.

$ echo $ORACLE_HOME
$ echo $ORACLE_SID
$ echo $LD_LIBRARY_PATH
$ echo $PATH

2. On AIX, HP-UX, Linux, MacOSX, Solaris, Tru64 system make sure kernel parameters settings are ok. To set, check and modify your kernel parameters have a look at the post How to check and modify Kernel Parameters in Linux
and Install Oracle on Linux.

3. There may have incorrect permissions on the ORACLE.exe
The 'ls' command should show permissions 6751 (as follows)

$ cd $ORACLE_HOME/bin
$ ls -l oracle

The output should be
-rwsr-s--x 1 oracle dba

If not then please execute the following
$ chmod 6751 oracle

4. Check whether current ulimit settings is ok.
$ ulimit -a

A sample output is,

$ ulimit -a 
    core file size        (blocks, -c) unlimited 
    data seg size         (kbytes, -d) unlimited 
    file size             (blocks, -f) unlimited 
    open files                    (-n) 256 
    pipe size          (512 bytes, -p) 10 
    stack size            (kbytes, -s) 8192 
    cpu time             (seconds, -t) unlimited 
    max user processes            (-u) 29995 
    virtual memory        (kbytes, -v) unlimited 

If open files (-n) is set to lower then make it unlimited or set it to a higher value, for example:
$ulimit -n 4096

5. Check the permission on the library files under $ORACLE_HOME/lib and $ORACLE_HOME/lib32 are ok. Since since sqlplus and other binaries require these libraries so if sqlplus does not have permission on these file it may throw ORA-12517: TNS: lost contact. It should have 755 on unix system.

You can give 755 permissions to $ORACLE_HOME/lib and $ORACLE_HOME/lib32
$ chmod -R 755 $ORACLE_HOME/lib
$ chmod -R 755 $ORACLE_HOME/lib32
$ cd $ORACLE_HOME/bin
$ relink all

Troubleshoot ORA-12547: TNS: lost contact

Problem Description
Whenever you connect to database as sysdba it fails with ORA-12517 like below.

$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.2.0 - Production on Sun Aug 01 11:27:27 2010
Copyright (c) 1982, 2005, Oracle. All Rights Reserved.
ERROR:
ORA-12547: TNS:lost contact
Enter user-name:

Cause of the Problem
ORA-12547 indicates that the communication channel has been broken. Based on the scenarios cause and solution of the problem is discussed below.

1)Local connection as sysdba (Bequeath):
Problem
BEQ connection fails when connecting with / as sysdba

Cause
Oracle binaries have not been linked correctly

Solution
Relink the Oracle binaries by executing the following command,

$ ORACLE_HOME/bin relink all

2)Bequeath connections fail with ora-12547 and Remote connections fail with ORA-12500:

From the listener.log file it shows,

TNS-12500: TNS:listener failed to start a dedicated server process 
TNS-12547: TNS:lost contact 
TNS-12560: TNS:protocol adapter error 
TNS-00517: Lost contact 

The version of the database server is 9.2.0.2

Cause
This is oracle bug 2654576 and happened due to the processes value reaches a limit.

Solution
i) The bug is fixed in patch set 9.2.0.3 and in 10g. So upgrade oracle database is a solution.

ii) Increase the PROCESSES parameter in the init.ora to a higher value for example 2000.

iii) If increasing the PROCESSES parameter does not help then increase the value of the hidden parameter.
_attach_count_slack = 2000

3) Remote connections to the database server fail with ORA-12547
Cause 1
SQLNET.INBOUND_CONNECT_TIMEOUT and/or INBOUND_CONNECT_TIMEOUT_listener_name is set in the database server's sqlnet.ora and listener.ora. If the client fails to establish a connection and complete authentication in the time specified defined by these parameter, then the database server terminates the connection.

If this is the case and your oracle database version is 10g and higher then ORA-3136 errors is reported in the alert.log.

Cause 2
TCP.VALIDNODE_CHECKING is active on the database server and the TCP.INVITED_NODES list does not have the IP address of the failing client.
Alternatively the TCP.EXCLUDED_NODES list contain the IP address of the failing client.

Solution 1
If problem happened due to cause 1 then SQLNET.INBOUND_CONNECT_TIMEOUT and/or INBOUND_CONNECT_TIMEOUT_listener_name to appropriate values.

Note that the database server and the listener has to be restarted for these parameters to take effect.

Solution 2
For cause 2 either add the IP address of the failing client in the TCP.INVITED_NODES list or remove it from the TCP.EXCLUDED_NODES list.

It is recommended to restart the database server and the listener for these parameters to take effect.

4) Listener fails to start with Oracle error ORA-12547
Cause
TCP.VALIDNODE_CHECKING is active on the database server and the TCP.INVITED_NODES list does not have the IP address of the failing client.
Alternatively the TCP.EXCLUDED_NODES list contain the IP address of the failing client.

Solution
Either add the IP address of the failing client in the TCP.INVITED_NODES list or remove it from the TCP.EXCLUDED_NODES list.
It is recommended to restart the database server and the listener for these parameters to take effect.

5) After changing /etc/system and rebooting system, the 10g R2 TNS Listener fails to start

$ lsnrctl start 
Starting /u01/oracle/product/10.2.0/Db_1/bin/tnslsnr: please wait... 
TNSLSNR for Solaris: Version 10.2.0.1.0 - Production 
System parameter file is /u01/oracle/product/10.2.0/Db_1/network/admin/listener.ora 
Log messages written to /u01/oracle/product/10.2.0/Db_1/network/log/listener.log 
Trace information written to /u01/oracle/product/10.2.0/Db_1/network/trace/listener.trc 
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=server11)(PORT=1521))) 
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=extproc10))) 

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=server11)(PORT=1521))) 
TNS-12547: TNS:lost contact 
TNS-12560: TNS:protocol adapter error 
TNS-00517: Lost contact 
Solaris Error: 131: Connection reset by peer 
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=extproc10))) 
TNS-12541: TNS:no listener 
TNS-12560: TNS:protocol adapter error 
TNS-00511: No listener 
Solaris Error: 146: Connection refused 

Cause
This one is happened due to a DNS client process, 'BIND 9' not running/started on the Solaris 10 Server.

Solution
You need to start the BIND 9 DNS Client on the Solaris10 Server.

In 10g listener log WARNING: Subscription for node down event still pending

Symptoms of the Problem
In the listener log file you constantly get the following warning message.
WARNING: Subscription for node down event still pending

If you have oracle database greater than 10g or newer version or 11g then in the listener log file you get the warning message.

Cause of the Problem
The warning messages are related to the Oracle TNS Listener's default subscription to the Oracle Notification Service (ONS). This subscription to ONS is introduced in Oracle 10g for RAC environment. Listener subscription to ONS is useful to use advanced features like Fast Application Notification events(FAN) , Fast Application Fail over (FAF) and Fast Connection Failover (FCN) in RAC. So in a non-RAC environment subscription to ONS is not needed. So in a standalone system we can disable it and thus avoid warning message.

Solution of the Problem
Disable subscription for listener to ONS. This can be done by setting the following parameter in the listener.ora.

SUBSCRIBE_FOR_NODE_DOWN_EVENT_{listener_name}=OFF

Where {listener_name} should be replaced with the actual listener name configured in the LISTENER.ORA file.

Suppose your have default listener name and it is LISTENER. Then in the listener.ora file(by default in location $ORACLE_HOME/network/admin on unix) add the following entry in a new line,

SUBSCRIBE_FOR_NODE_DOWN_EVENT_LISTENER=OFF

After that you need to stop and start the listener by,
lsnrctl stop
lsnrctl start

Alternatively you can reload the listener if availability is important to you. Do it just by,
lsnrctl reload

This will prevent the messages from being written to the log file.

This changes also prevent the TNS listener hanging intermittently which will be discussed in another topic.

Note that, setting the above parameter OFF in listener.ora disables a necessary RAC functionality.

Related Documents

The listener supports no services

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

ORA-12541: TNS:no listener

How to Enable Listener Logging and Tracing.

lsnrctl start fails with TNS-12541, TNS-12560,TNS-00511, Linux Error: 111:

ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

ORA-12557: TNS:protocol adapter not loadable

Problem Description
In my machine I had oracle 10g home , using sqlplus of 10g I could connect to an Oracle database 10g. Now I have installed a new oracle 11g home, but using sqlplus of 11g I could not connect to Oracle database 10g. Below is an example,

With 10.2g sqlplus I can connect to 10g database.
C:\>e:\oracle\product\10.2.0\db_1\bin\BIN\sqlplus.exe maximsg/a@192.168.100.160/tiger

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Jan 26 01:54:10 2009

Copyright (c) 1982, 2005, Oracle. All rights reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

With 11g sqlplus I could not connect to oracle database 10g. It returns error message, ORA-12557: TNS:protocol adapter not loadable.
C:\>d:\app\oracle\BIN\sqlplus.exe maximsg/a@192.168.100.160/tiger

SQL*Plus: Release 11.1.0.6.0 - Production on Mon Jan 26 01:55:00 2009

Copyright (c) 1982, 2007, Oracle. All rights reserved.

ERROR:
ORA-12557: TNS:protocol adapter not loadable

Cause of the Problem
The problem happens because of two ORACLE_HOME are installed on your system. As after 10g you hav e installed 11g so whenever you write sqlplus by default new 11g binaries are selected and raises ORA-12557. But working with old home 10g works fine.

Simply sqlplus does not work but 10g home location sqlplus (e:\oracle\product\10.2.0\db_1\bin\BIN\sqlplus.exe ) works.

C:\>sqlplus.exe maximsg/a@192.168.100.160/tiger

SQL*Plus: Release 11.1.0.6.0 - Production on Mon Jan 26 22:47:08 2009

Copyright (c) 1982, 2007, Oracle. All rights reserved.

ERROR:
ORA-12557: TNS:protocol adapter not loadable

Connecting to old oracle database using new binaries are not supported in oracle and error will return.

Solution of the Problem
Only setting ORACLE_HOME is not sufficient on windows environment. Because the location is taken from windows registry. So either uninstall newer oracle home or explicitly pointing to old oracle binaries will solve the problem.

Here using pointing to old home,
C:\>e:\oracle\product\10.2.0\db_1\bin\BIN\sqlplus.exe maximsg/a@192.168.100.160/tiger

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Jan 26 01:54:10 2009

Copyright (c) 1982, 2005, Oracle. All rights reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

Alternatively you can follow below.

Step 01: Remove registry entries of new ORACLE_HOME.
To do this,
i)Type regedit on Run.
ii)Press enter and expand HKEY_LOCAL_MACHINE.
iii)Then expand SOFTWARE and then expand ORACLE tab. There you will see two oracle home. Right click on the one that you want to delete and then select delete. If prompting click yes.

Step 02: Remove any environmental variable.
i)Right click on My computer icon. Then select properties.
ii)System properties window will appear. Click on Advanced tab.
iii)Select environmental variables.
iv)Find the variable/system variable path and ORACLE_HOME. Edit or modify them so that it point to you desired sql*plus.
Usually in the PATH system variable you will get both ORACLE_HOME path. Just remove one path. Of course if you have ORACLE_HOME variable settings first delete the key.