In general. It's very hard to use concurrency to control bandwidth
usage.
If your system is concurrently sending a 100 messages to one server
that's on the other end of a modem link, does that use more of your
bandwidth than one MP3 email going to a high capacity site like Yahoo?
No. The single email to Yahoo will probably blast out and fill your
capacity.
You need to dive into the world of traffic shapping which is done at
the network level if you really want to control the bandwidth consumed
by email.
Oh, I don't understand why you'd get bounces due to limited
bandwidth. Most qmail installations retry a mail if the delivery
fails, what does your qmail do?
Regards.
On Fri, May 25, 2001 at 08:06:26AM -0600, Charles Cazabon allegedly wrote:
> Smith, Lisa <[EMAIL PROTECTED]> wrote:
> >
> > What I'd like to know is if anyone has come up with a script that can modify
> > qmails concurrencyremote setting "on the fly" based on available bandwidth?
>
> Not to my knowledge. I've seen people mention the possibility before, but
> never seen a proposed solution.
>
> > Basically what I am looking for (and we may write in-house if no one has
> > something similar out there), is a script that would be able to detect the
> > available bandwidth, and adjust qmail's concurrencyremote setting, so that
> > we're not sending too much (or too little) traffic out that pipe.
>
> Changing the remote concurrency is fairly simple; write your new value to
> /var/qmail/control/concurrencyremote and restart qmail. It might take a
> minute or two to stop if there are remote deliveries in progress. You could
> theoretically do this in a shell script called from cron every ten minutes or
> so. Measuring "available bandwidth" is, of course, the tricky part.
>
> > The problem that we're running into is that our machines are either sending
> > out too much at once (concurrency set 'too high'), causing failed
> > connections, and bounces, else the machines are throttled back
> > (concurrencyremote set 'too low') not taking advantage of the available
> > bandwidth.
>
> Why not just pick the highest value that still leaves you sufficient bandwidth
> for other purposes? qmail may not use all the available bandwidth, but it
> will keep moving the mail out throughout the slow times, and should even out.
>
> Charles
> --
> -----------------------------------------------------------------------
> Charles Cazabon <[EMAIL PROTECTED]>
> GPL'ed software available at: http://www.qcc.sk.ca/~charlesc/software/
> Any opinions expressed are just that -- my opinions.
> -----------------------------------------------------------------------
