Re: Notifications

On Thu, Dec 16, 2004 at 05:44:09PM -0000, Donald Fraser wrote:
>
> Ok the problem is that outside our local network, and more precise on the
> outside of our firewall, users do not receive NOTIFY messages. The exact
> same software running on the local network, albeit not using SSL does
> receive NOTIFY messages.

As with the inside-vs-outside issue, SSL might be a red herring.
It's curious that the same software behaves differently in different
locations, but be careful not to use tunnel vision when investigating
the cause.

Is there *anything* else that's different between the systems whose
connections work and those whose don't?

Is it possible that the outside users are connecting to a different
database server than the inside users?

What OS are you using, what language, what database interface? How
are you checking for NOTIFY messages?

> The problem is immediate, I can instanciate the sending of a NOTIFY message
> from my own connection and I don't receive a return message yet users on
> the local network do.

Have you done simple tests with psql? You'd probably have to issue
a query before seeing the notification, but that should still tell
you if the notification arrived at all.

> Basically now that I know NOTIFY uses TCP and therefore "should" clearly
> not be getting lost anywhere, I will do a lot more investigating into our
> software as that is the most likely place for the proble!. It just seems a
> bit strange that the same software can receive messages when on the local
> network... The one thing I can be sure of is that it will be software! I
> think the clue must be the setting up of SSL on our software....

Again, beware of putting on blinders. If the database connection
is otherwise working then it would be strange if SSL configuration
were causing the problem. *Is* the connection otherwise working?

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