[Mimedefang] MIMEDefang + spamd

[John Scully]

I found a very large performance increase by using spamc/spamd over the
Mail::SpamAssassin module for several reasons:

1) The compiled C spamd processes messages faster then the perl module. I
know it should not....but if you have a lot of custom rule sets there is a
real difference.  Since we have the Mimedefang working dir on ramdisk there
is virtually zero overhead of having spamc feed the message to spamd.
2) We run DCC via dccifd before SA and don't bother running SA if DCC has
the message listed.
3) We check account status, quota, blacklists etc before running SA

These last two items mean that SA is run on only about 1 out of 4 messages -
epecially when we are under some sort of dictionary spam attack.  We have 60
MD slaves runing, but only 15 SA threads (and it never ties up all 15).
Since we run a LOT of custom rule sets each SA thread is about 50M, so if I
had SA embedded in each MD slave SA would be consuming 3G of memory instead
of 750M.

I also found a huge gain by using an old server to load local RBLs using
rbldnsd from www.surbl.org.  This is a good use for that PII linux server
lying around, as the load is so low as to be difficult to measure, and
rbldnsd uses less then 100M memory.

John Scully
iSupportISP.com


----- Original Message ----- 
From: "Kelson" <kelson at speed.net>
To: <mimedefang at lists.roaringpenguin.com>
Sent: Wednesday, September 22, 2004 1:26 PM
Subject: Re: [Mimedefang] MIMEDefang + spamd


>
> Matthew.van.Eerde at hbinc.com wrote:
> > What's the conventional wisdom with using MIMDefang and SpamAssassin?
>  > Can MIMEDefang invoke spamc to communicate with spamd?  Is this better
>  > than calling the Mail::SpamAssassin perl module directly?
>
> No, and no.
>
> Since MD is already in Perl, invoking spamc and calling spamd would just
> be extra overhead.
>
> -- 
> Kelson Vibber
> SpeedGate Communications <www.speed.net>
>
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