RE: sqlplus scott/tiger@tnsname hangs

From: <>
Date: Thu, 17 Apr 2008 21:13:14 -0600
Message-ID: <000b01c8a102$25c5b6a0$6501a8c0@BHAIRAVIPC01>


A long shot, and perhaps as a process of elimination:  

  1. Do you have any logon triggers (I am not sure personally, if the logon trigger fires before acknowledgement it sent back to the client)
  2. As perhaps a consequence, I wonder if you reached the max sessions per dispatchers and max dispatchers and got blocked

Again a longshot given that things cleared up when you killed the session in the beginning of the queue  


From: [] On Behalf Of Prasad
Sent: Thursday, April 17, 2008 5:57 AM
To: David cheyne
Subject: Re: sqlplus scott/tiger_at_tnsname hangs  

Hi David/Jack,

Listener Logging was switched off on this database . This is a solaris 9 server .


On Thu, Apr 17, 2008 at 3:09 AM, David cheyne <> wrote:


You say that the listener log was not enabled. Have you switched off the logging or was it not updating? You don't say which O/S your on, but you can easily automate its management.  

Without bringing the listener down on Unix/Linux:  

cp listener.log listener.OLD

cat /dev/null > listener.log  

This copies the log to another name and blanks the current log. You just may need to watch disk space if your keeping multiple copies (tar/zip?)      

David Cheyne    

On 17/04/2008, Jack van Zanen <> wrote:

maybe check the size of your listener.log file  

I have seen occasions where a large log file saw this behaviour  


On 17/04/2008, Prasad <> wrote:


This was something that happened today in one of the database and I am looking for list's
response on this. This is a Oracle <> database running solaris 9.

Around 10am the Unix group called me and told me that one of the osprocess is taking more cputime
then what it normally takes. and upon investigation I found that this database was running on
shared server mode with the osprocess being the only dispatcher at that time . So I created another
3 dispatcher and stopped the existing dispatcher d000.

and everything was going fine until 2.30pm when the user called me and told me that he is not able to
make connection using servicename. so I did a test

test1- sqlplus '/as sysdba' 
test2- sqlplus scott/tiger  
test3- sqlplus scott/tiger_at_tnsname

I was able to logon to database successfully with test1 and test2 . However when I did test3
it just hangs and it didnt allow me to interrupt it also.

I checked if the dispatchers were busy or not and didnt found anything significant.
The listener logging was not enabled so the initial reaction was to shutdown and start the
listener which I did and at this time the test3 worked fine . However the user was still not able to
access its application and I observed a large number of session in dba_blocker and dba_waiter
and also few deadlock error in alert log file . So I killed the session on the beginning of the queue
and it immediately releases all the sessions in dba_blockers and dba_waiters and the user was
able to access the application.

Here comes the hard part what is the root cause of this issue?

Please advise.



J.A. van Zanen


David Cheyne
Oracle Database Administrator
  • Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read. Groucho Marx

-- Received on Thu Apr 17 2008 - 22:13:14 CDT

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