spamd vs. builtin SA (was Re: [Mimedefang] Patch: adding custom headers for SpamAssassin)

[Jan-Pieter Cornet]

On Thu, Nov 23, 2006 at 10:00:01AM -0500, David F. Skoll wrote:
> > But, given the fact that we just switched to using spamd instead of
> > the builtin Mail::SpamAssassin modules, we don't really need support
> > builtin to mimedefang at the moment either...
> 
> Just curious: Why the switch?  Do you see better performance?

Yes, but mainly due to better memory utilisation, and because of
our specific setup.

We don't scan everything with SpamAssassin, about 25% of the mails
are scanned with SA, the rest are only virus-checked, or checked
against the remote SMTP server.

Loading SpamAssassin in memory requires about 25MByte, and with
50 mimedefang slaves, that adds up. Some of our servers were
swapping occasionally, especially when some large map-building
processes were being run, eating another 500MB of RAM.

We are now using about 5 busy spamd slaves, with very occasional
peaks to 15.

Of course, if every email is run through spamassassin, there probably
isn't a lot to gain.

-- 
Jan-Pieter Cornet <johnpc at xs4all.nl>
!! Disclamer: The addressee of this email is not the intended recipient. !!
!! This is only a test of the echelon and data retention systems. Please !!
!! archive this message indefinitely to allow verification of the logs.  !!