Re: An I/O error occured while sending to the backend

On Wed, 2005-04-06 at 11:24, John R Pierce wrote:
> Anthony Chaffey wrote:
> > Hi,
> >
> >
> > I have developed an application using the postgresql-8.0-310.jdbc3
> > driver and connecting to a postgresql 8.0.1 database running on fedora
> > core 3. Everything was working fine until i started running the
> > application on the clients pc's. Randomly they receive an error, the
> > stack trace of which is below.
> >
> > The only difference between my testing pc and the client's pc's is that
> > they use a wireless network card. Both my machine and the client's pc's
> > are running Windows XP with SP2. Similar problems have been posted on
> > this mailing list and people have suggested a firewall is clearing the
> > connection which makes sense as the client claims this problem only
> > occurs if the application is left idle for a short time but does anyone
> > have any more information that may help?
>
> its probaly exactly what you say, most firewalls, NAT routers, etc will time
> out idle sockets after a certain number of minutes...   They have to do this,
> otherwise the firewall's connection tracking tables will fill up with old flug.
>
> only good solution is to catch the exception, and attempt to reopen the
> database connection, and retry the operation....

Does setting a lower tcp_keepalive_time help these problems with NAT?
It certainly fixed the problems I've seen with non-NAT firewalls.  (this
is a linux kernel setting, i'm sure there's an equivalent for other
unixes)