Skip to Content.
Sympa Menu

freetds - [freetds] Strange error -- side effect of persistent connections or FreeTDS problem?

freetds AT lists.ibiblio.org

Subject: FreeTDS Development Group

List archive

Chronological Thread  
  • From: "Michael Sims" <michaels AT crye-leike.com>
  • To: <freetds AT lists.ibiblio.org>
  • Subject: [freetds] Strange error -- side effect of persistent connections or FreeTDS problem?
  • Date: Fri, 25 Feb 2005 08:07:28 -0600

Hi guys,

I broke one of my major rules yesterday by changing several things at once
involving the setup of one of our websites (PHP 5.0.3, Apache 1.3.33,
FreeTDS + PHP's ext/sybase_ct). I upgraded to FreeTDS 0.63RC10 yeserday and
I also implemented persistent connections in PHP/Apache using PHP's
mssql_pconnect(). Late last night I started getting a new (to me) error
message when calling mssql_select_db():

Sybase: Client message: Attempt to initiate a new SQL Server operation with
results pending. (severity 78)

None of my queries have changed in the past several months, so I'm nearly
positive that this isn't an issue with my code attempting to issue any
strange queries.

I'm thinking that it might be a problem with an incomplete/improper shutdown
for one request, and that connection going back into PHP's persistent
connection pool and triggering the same error each time it's re-used. If
this is the case I'm not sure if there's any workaround other than
restarting apache, since I cannot force a persistent connection to close or
reset itself purely in PHP.

I've also seen some things that indicate this may be a network-related
problem with an incomplete connection. My persistent connections are
crossing a firewall, and I'm sure this firewall has an idle timeout. I did
some testing yesterday with ethereal and it seemed that these persistent
connections were sending periodic keep-alives over the link but I suppose
it's still possible that a connection became unstable.

The last possibility is a bug in FreeTDS. I basically wanted to check with
the list and see if anyone has experienced this and if they thought it could
be a FreeTDS bug. Should I try using the latest development version?
(freetds-0.64.dev) Is that too bleeding edge for a production box? Or
should I just give up on trying to use persistent connections over a
firewall? Any advice would be very much appreciated...

___________________________________________
Michael Sims
Project Analyst - Information Technology
Crye-Leike Realtors
___________________________________________






Archive powered by MHonArc 2.6.24.

Top of Page