[freetds] FreeTDS hangs when running a select
serversage at gmail.com
Tue Apr 8 13:11:18 EDT 2008
Alrighty guys, I'm on the network bandwagon. I'll start putting feelers out
into the pfSense community to see if any of them have ideas (pfSense is the
firewall/router we are currently using). It's possible Racoon has an issue
with this particular VPN endpoint the client has or something.
Unfortunately, the Windows end isn't a system/network we have any kind of
access to, other than the database. It's in a doctor's office, and our
chances of finding an IT guy that is willing to either let us look at it, or
to do it himself, are pretty much 0.
I will try the SACK setting when I get home tonight and see if any magic
happens. I'll also see if we can get one of their IT guys to be "cool". :)
Thanks guys, your help has been greatly appreciated. And I mean GREATLY.
Helping with a problem that exists outside the scope of the software was
above and beyond the "call of duty".
On Tue, Apr 8, 2008 at 7:03 AM, James K. Lowden <jklowden at freetds.org>
> Brian Johnson wrote:
> > The Windoze system works great (returns
> > all the rows). But both linux systems choke.
> Consistent with a network issue, pointing to the firewall. :-/
> > The log
> > created when setting TDSDUMP did indeed seem to indicate that there was
> > no problem, data just stopped flowing. ...
> > Any ideas? Any where I can point a finger and say, "Aha! I have
> > something to update!"?
> You may find that something simple, say, ftp, fails if the file is large
> enough. That would eliminate the whole application layer and focus
> attention on the network.
> In case Hildo's selective ACK suggestion doesn't do the trick, the
> technical path would be to use tdsdump(8) to log the connection, and watch
> the server stop sending when it shouldn't. For extra credit, scope the
> server's side, too. It's work, and some shops don't have the chops. With
> luck you'll find either the "stuck" packet, the one the server sent that
> the client never received, or you'll see the server mysteriously stop
> sending even though the client is waiting and has abided by the TCP/IP
> (Windump works pretty well if you have the tcpdump man page handy, but I
> have never used it with a VPN.)
> Lament: Observe the negative network effect of Windows. Your firewall
> "works great" with the Windows machines, but not with Linux. Your choice
> is to fight or switch, and fighting requires knowledge and patience ...
> and possibly new VPN software. Who can blame the person who looks at that
> scenario before it even begins, and decides not to go there?
> Anyway, good luck. Please post the outcome if you would. Someone else
> might benefit.
> FreeTDS mailing list
> FreeTDS at lists.ibiblio.org
More information about the FreeTDS