On Tue, Jul 06, 2010 at 01:00:14PM -0700, Florin Andrei wrote:
> Having multiple exit points seems to improve the overall delivery speed -
> this is true even right now, when distribution is skewed to the faster
> server 4:1. My estimate is, a near-1:1 distribution would actually fix our
> time-constraint problem even before whitelisting. So you see how this is
> kind of a big incentive to get it done.
So you have multiple exit points with non-uniform latency, but the more
severe congestion is downstream, so you want to load the exit points
uniformly. Yes, the solution is to disable the connection cache, and
set reasonably low connection and helo timeouts in the transport feeding
the two exit points, so that when one is down and non-responsive (no TCP
reset), you don't suffer excessive hand-off latency for 50% of deliveries.
master.cf:
transp unix ... smtp
-o smtp_connect_timeout=$<transp>_connect_timeout
-o smtp_helo_timeout=$<transp>_helo_timeout
main.cf:
# default is 30s
transp_connect_timeout = 2s
# default is 300s
transp_helo_timeout = 30s
--
Viktor.
