Hi this mail ius just to say thanks all the people kindly sent me a
mail trying to figure out the low performance in my server.
Right now the server is working well and filtering like I wish. The
changes I did were decrease the number of amavisd processes to 5,
turned off DCC, the network tests and install the DNS service
locallly.
Thanks all. Regards.
On Thu, 2008-11-06 at 01:07 +0100, Mark Martinec wrote:
> Luis,
>
> > I was doing some tests with all the recommendations you sent me...
> > and I can make to work the server correctly... I was filtering spam with
> > no problems and my performances troubles dissapeard...
> >
> > I just configured 5 procs for amavis and postfix content filter and
> > I turn off the network tests... the server can filter a lot of spam and
> > delivery quickly... but now appears another problem :(
>
> With your 4 CPU 4 GB mem box you should be able to run more than 4
> amavisd(+SA) processes. As a rule of a thumb, I'd say your box should
> not have trouble running 20..30 processes.
>
> > Until today morning... I was filtering and deliverying fine, but
> > suddenly I received these messages and the delivery is sooo slow and
> > the mail queue just is growing and growing....
> >
> > Nov 5 12:51:23 mailgw postfix/qmgr[14251]: warning: mail for
> > [127.0.0.1]:10024 is using up 4001 of 4004 active queue entries
>
> This is just a consequence of your amavisd+SpamAssassin not being able
> to keep up with the incoming mail flow. No fine tuning on the Postfix
> side will be able to compensate for the fact that your mail inflow rate
> is larger than the mail processing throughput of SpamAssassin filtering.
>
> What is your message rate on a normal day? Is the current mail flow
> significantly larger? Perhaps you are under a bounce storm, which can
> easily increase the mail flow rate by an order of magnitude. Examine
> what kind of messages are most typical in your mail queue (mailq, postcat),
> try to determine if these are just normal spam flow, or bounces, or
> something else (e.g. mailer abused as an open relay, perhaps by one of
> your client PCs which might have been zombiized).
>
> What is the message throughput though the filter - see what amavisd-agent
> has to report, the more interesting figures are for example:
>
> CacheAttempts 15216 3217/h 100.0 % (CacheAttempts)
> CacheHits 1750 370/h 11.5 % (CacheAttempts)
> ...
> InMsgs 15216 3217/h 100.0 % (InMsgs)
> InMsgsBounce 4176 883/h 27.4 % (InMsgs)
> InMsgsBounceKilled 3904 825/h 93.5 % (InMsgsBounce)
> ...
> TimeElapsedDecoding ...
> TimeElapsedPenPals
> TimeElapsedReceiving
> TimeElapsedSending
> TimeElapsedSpamCheck
> TimeElapsedVirusCheck
> TimeElapsedTotal
>
> How does the display of amavisd-nanny look like? Are all processes
> about evenly busy? Are processing times significantly longer than a
> couple of seconds? Set $nanny_details_level=2; (in amavisd.conf) for
> more detailed timing breakdown by amavisd-nanny.
>
> Check timing log (at log level 2), you may want to (re)confirm that
> SpamAssassin is really taking most of the time, just in case.
>
> > -I turned off DCC, Razor and Pyzor.
> > -I set the bayes use to 0.
>
> These were pretty drastic measures, significantly affecting quality
> of SA results. Once you get over the current crisis, at least put back
> the DCC and Bayes on MySQL, which are relatively low resource consumers
> compared to regexp-based rules and to Pyzor (razor is somewhere inbetween).
>
> Mark
>
>
Luis Croker
SCSA - SCNA
Administrador de Sistemas
Megacable Comunicaciones
GPG Key1024D/48C1764B
Key fingerprint = E8B6 E84F ECE4 661E 30C7 7208 042D BD09 48C1 764B
