Re: Dead Connection Detection is ... dead?

  • From: "Alex Gorbachev" <gorbyx@xxxxxxxxx>
  • To: fnmpa@xxxxxxx
  • Date: Fri, 13 Oct 2006 19:36:51 -0400

Did you set it on client side as well?

On 10/13/06, Mark Anderson <fnmpa@xxxxxxx> wrote:
My apparent problem is that my server is not sending DCD probe packets
to my client even though SQLNET.EXPIRE_TIME=1 in

Oracle server is on Red Hat EL release 3
Oracle client is on Fedora Core release 3

Between client and server is a router which is deliberately configured
to close any connection which is idle for longer than a configured
length of time (presently 70 seconds, although this is negotiable).

To keep the connection open by ensuring there was activity on the
connection every 60 seconds I added the following lines to


Trace files started to appear in /home/oracle.  Most, but not all,
contained a line like:

[13-OCT-2006 21:29:44:296] niotns: Enabling dead connection detection (1

and lines like

[13-OCT-2006 21:29:44:309] nstimini: entry
[13-OCT-2006 21:29:44:309] nstimig: entry
[13-OCT-2006 21:29:44:309] nstimig: normal exit
[13-OCT-2006 21:29:44:309] nstimini: initializing LTM in asynchronous mode
[13-OCT-2006 21:29:44:309] nstimini: normal exit
[13-OCT-2006 21:29:44:309] nstimstart: entry

Which are described in Note 151972.1 "Dead Connection Detection (DCD)
Explained" as evidence that DCD is enabled.  The trace files without
these lines were very short.

I opened a connection to the server from the client (which was otherwise
idle) using a Oracle DBI script that did nothing but log in and sleep at
the client.  Our network admin monitoring the router could see the
connection appear between the client host and port 1521 of the server
host and the 70-second clock start to tick.  It counted down to 0
without resetting, from which I infer that no DCD probe packets were
sent from the server to the client.  Is this inference reasonable?  If
it is, does anyone know why the DCD probe packets weren't sent?

Thanks in advance,



Best regards,
Alex Gorbachev

The Pythian Group
Sr. Oracle DBA

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