On 2009-02-22 at 20:23 -0800, Marc Perkel wrote:
> Just wondering about the 4096 connection barrier. With the size of
> servers these days it's easy to build a box that can handle 4096
> connections at once. Any chance of eliminating it in the next release?
More than 4096 connections, all actually doing work? Sounds more like
you're discovering the down-side to tar-pitting within Exim, instead of
in a small daemon dedicated to tar-pitting.
src/daemon.c, the limit is a sanity-check on smtp_accept_max; as far as
I can see from skimming the source, this isn't used to keep any
collections within the size of another data structure, such as might be
passed to select().
So you should be safe to just increase the maximum check.
Note though that some other stuff scans linearly through smtp_slots
assuming that this is a fairly lightweight approach. If you're raising
this to a much higher figure, Exim might spend more and more time
scanning smtp_slots for every connection -- just keep an eye on the CPU
usage of the main daemon and, if it gets out of hand, you've raised the
limit too far. You might then consider submitting a patch to change the
relevant logic to something which scales better.
> And - is there going to be a 4.70 version? What's new and exciting in
> development?
Yes.
ChangeLog:
http://vcs.exim.org/viewvc/exim/exim-doc/doc-txt/ChangeLog?view=markup
NewStuff:
http://vcs.exim.org/viewvc/exim/exim-doc/doc-txt/NewStuff?view=markup
Regards,
-Phil
