On Thu, 2004-03-25 at 17:35, Dean Brooks wrote:
> We are running Exim 4.30, and are considering using MySQL lookups
> in our Exim config in various spots.
>
> However, we run a fairly high volume mail server and I am concerned
> that MySQL database connections will have to be rebuilt for each new
> incoming message.
The model that exim uses is one long lived listener process (assuming
you are running "exim -bd"), which forks relatively short lived
processes that deal with each incoming connection (and they can further
fork off delivery processes - also short lived).
This means that any database connection *has* to be opened in the per
connection handler (ie a short lived process) because otherwise you have
multiple processes trying to use a single fd/socket connection to a
database with consequent synchronisation problems.
My preferred solution to this is to have loosely coupled servers where
the database is dumped to a local copy - I tend to use cdb files - so
that things keep working if any single component dies off.
However an alternate solution is to use something like sqlrelay which
looks good in theory. If anyone is using this in conjunction with exim
then I would be very interested in them writing up details of this.
Nigel.
--
[ Nigel Metheringham Nigel.Metheringham@??? ]
[ - Comments in this message are my own and not ITO opinion/policy - ]
