From: Victor Duchovni (no email)
Date: Fri Mar 19 2010 - 11:13:31 EDT
On Fri, Mar 19, 2010 at 03:58:42PM +0100, Attila Nagy wrote:
> I have a somewhat busy mail relay running postfix 2.7, which has problems
> with a slow destination.
> I can't limit the number (or rate) of incoming e-mails for that domain, and
> I can't increase the throughput of the destination, because I don't operate
> it (OK, that may be false, because postfix's destination concurrency
> adjusments can make it worse than what it could accept).
Forward mail for this domain to a separate queue (Postfix instance)
that handles mail for this---and perhaps some other similar---domains.
The slow domain will no longer clog your primary queue.
> And this is one for citromail:
> Mar 19 15:47:47 mail postfix/smtp: 28E47768F4: to=<@citromail.hu>,
> relay=server03.citromail.hu[18.104.22.168]:25, conn_use=76, delay=9538,
> delays=5062/4475/0/0.33, dsn=2.0.0, status=sent (250 ok 1269010067 qp
The latency of "0.33" seconds is not unreasonably high. Is this typical
for deliveries to this domain? With a concurrency of 20, you should be
able to deliver ~60 messages per second to this destination. Can you
compute a "smoothed" latency for this destination?
initialize: lavg := 0;
count := 0;
step: lavg := lavg * 0.95 + (c + d) * 0.05;
count := count + 1
if (count % 100 == 0)
The "c" and "d" values would be the sum of the connection and delivery
delays in the log entry.
How many concurrent connections do you have for this destination?
What is the destination concurrency limit?
-- Viktor. P.S. Morgan Stanley is looking for a New York City based, Senior Unix system/email administrator to architect and sustain our perimeter email environment. If you are interested, please drop me a note.