Re: [exim] 4096 connection barrier

Marc Perkel wrote:
> Well, I'm not up to 4096 yet but often run 900 on Monday mornings. I'm
> filtering spam for over 4000 domains and this is the main box. I might
> have a project coming up processing far more volume that now.
>
> This box is fast. I'm offloading spamassassin on several other servers.
> I'm using a ram disk for the email queue. I might be adding another
> 12,000 domains. I'm not doing a lot of delays, although I do throw in a
> few seconds of suspicious connections but no more than 10 seconds total.
> So although 4096 sounds like a lot if you throw enough email volume on
> it you can get there.

The 4096 limit might be more aimed at the limits imposed by linux
itself. There are open file descriptor limits (default limits are 1024
per process) which you may reach. I suspect there would be some others
too, but they are all trivial to increase. It's just a matter of
adjusting them all which is why this would be considered a local tuning
customisation and not something that would enter the distribution code base.

I know you already use multiple MX records, have you considered
splitting the MX onto different machines so that you have a fail over?
Or use round robin DNS to split the traffic between multiple machines?