> -----Original Message-----
> From: Andrew McNaughton [mailto:[EMAIL PROTECTED]
> Sent: Monday, 23 June 2003 5:03 PM
> To: James Gray
> Subject: Re: [SLUG] Opinions sought: Exim vs Sendmail
> 
> 
> 
> It sounds to me like you might want to allow more concurrent processes
> than you are at present.  Also, the main resource you need more of is
> going to be memory.  Have your bean counters taken in that an 
> extra 512MB
> is really petty cash level expenditure?  In any case, is 
> there really any
> problem with allowing more concurrent accesses?
> 
> I agree with the suggestion about running your mail filter as 
> a daemon if
> possible.  If this serializes your filtering then it should 
> help a great
> deal.
> 
> Andrew

Spamassassin is already running as a daemon and chews up about 24Mb RAM
just for the parent process - that's almost 10% of our physical RAM!.
spamd children (according to vmstat + ps + top) are all reporting
similar usage (23-27Mb RAM).  As you suggest the lack of RAM is killing
us.  I did some burst load testing on it yesterday and found that
without limiting child processes for spamd it only took 15 messages in
under 5 seconds to sent system load to 15!  14 children of spamd caused
so much paging that the system ground to a halt (load peaked at 19!!).

So I did some quick calculations and decided 3 spamd children per CPU
(with 256Mb RAM) would be appropriate (given average time per message,
RAM, other process requirements etc).  I managed to send 50 messages in
7 seconds and system load hit 15 for less than 3 seconds and then
quickly returned to <1.  Paging was non-existent and no connections were
refused.  So startup scripts are now "spamd -m 3....."

So I've put in a capex request for an additional 512MB stick of RAM and
see where that gets us.  If I get the RAM, I'll increase the number of
spamd children to 6 or 7.  I've also put in a request for a 2nd CPU but
on a different capex :P  If I'm *REALLY* lucky, I might get both.....or
maybe not too.

Thanks to all for the pointers.  Looks like I might be able to tune perl
and spamassassin a little more to get a bit more out of it :-)

--James
--
SLUG - Sydney Linux User's Group - http://slug.org.au/
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