Simone Caruso:
> > I just simulated the performance hit of 256 incoming queues by setting
> >
> > hash_queue_names = incoming
> > hash_queue_depth = 2
> >
> > and running smtp-source, sending mail to an alias for /dev/null.
> >
> > Postfix queue performance for small messages already dropped by
> > 30%, with the write cache enabled on a 10,000RPM SAS disk (which
> > is recommended for a production server only when the write cache
> > has a battery to survive power failures).
> >
> > The performance drop will be worse with one queue directory per
> > customer, unless you have very few customers of course.
> >
> >
> I expected some degradation in performance, but not so much (you tried with a
> lot of queues too).
>
> I think the example environment is a mail marketing relay server, Giorgio
> said:
> "User A, with ip address IP_A, sends 1 different email to 1 million of
> different
> domain destinations"
>
> The indexing approach can fit this this specific application (marketing cloud
> service!?); the daemon
> don't need to scan on disk lots of hashes/subdirs. (a small size hash loadable
> in memory can be less expensive)
I reject solutions that require in-memory information about all
mail in the queue.
More generally, I reject solutions that cause Postfix to fail with
more than N messages in the queue, regardless of the value of N.
Wietse
