On Wed, Apr 02, 2008 at 03:15:03PM +0200, Rocco Scappatura wrote:
>
> > Thanks Gary,
> >
> > you're explanation is very brief and fully explanatory.
> >
> > I surely will execute some measurement of SA efficiency by
> > increasing log verbosity.
> >
> > In the mean time I find very embarassing some situations
> > where I have a congtestioned SMTP gateway server and I can't
> > avoid new incoming SMTP session from being managed by that
> > server (In this manner I only increase congestion. While I
> > like to let that server to 'digest' the queued mail traffic
> > before accepting new SMTP connection, and redirect the new
> > SMTP connection on other SMTP gateway server of my mail system).
> >
> > I use DNS balancing and when a queue on a server is
> > congestioned I get no effect from taking away that server
> > from being pointed by an MX record, because DNS changes
> > propagations take long time. :-)
> >
> > Is there any trick to tackle this issue?
>
> Any answer will be appreciate, even if it not came directly from Gary..
Heh.
As you have found, it's very difficult to do anything other than very
crude load management via DNS. Obviously you can make it a little bit
better by keeping your DNS TTLs short, but it's a very blunt tool.
The only load-balancing method that provides a more immediate and
tunable response is to use a different (non-DNS) approach, such as a
hardware load-balancer (I <3 my Foundry ServerIron) or some
routing-based software system such as CARP.
When one server is congested, your best bet and simplest soulution
may be to simply suspend the incoming SMTP by editing the postfix
master.cf file, temporarily comment out the line which has Postfix
listening on port 25, and reload Postfix. This is a drastic measure,
but I've used it from time to time to manually allow one server to
clear a big backlog. Once the backlog has cleared, you *MUST* remember
to uncomment the line and reload Postfix again, so that it can resume
accepting mail.
-- Clifton
--
Clifton Royston -- [EMAIL PROTECTED] / [EMAIL PROTECTED]
President - I and I Computing * http://www.iandicomputing.com/
Custom programming, network design, systems and network consulting services
-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace
_______________________________________________
AMaViS-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/amavis-user
AMaViS-FAQ:http://www.amavis.org/amavis-faq.php3
AMaViS-HowTos:http://www.amavis.org/howto/
