Re: Notifications

On Thu, Dec 16, 2004 at 02:20:07PM -0000, Donald Fraser wrote:

> I'm having problems receiving NOTIFY messages when outside our local network.

Define "problems." What are you doing, what are you expecting to
happen, and what actually does happen? Have you tested whether you
have the same problems when *inside* the local network? The
distinction between inside or outside may be a red herring.

> I have dissabled firewall setting but nothing seems to fix the problem.

What firewall setting did you disable and why? Best not to mess
around with things unless you have reason to think they'll work
(in other words, avoid using a stab-in-the-dark approach).

> I was wandering if NOTIFY messages use UDP or TCP, as that would
> possibly explain why they are not arriving?

PostgreSQL's NOTIFY messages ride inside your connection to the
database, so if you're connected across a network then they'll be
TCP. But you shouldn't have to do anything special to allow them:
if you can connect to the database then you'll get notifications.

A possible problem is that a firewall or other intermediate device
times out idle connections. Do you notice the problem after periods
of no activity?

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/