Preference for batch sizes

[Jeff A. Earickson]

Steve,
   You should probably give your DNS a good hard look.  When things
mysteriously delay like this, often the problem is lack of DNS
resolution.  You may have to get your network guys involved.
Made any changes to DNS lately?  Changed upstream network providers?
I did some quick "dig" action on domain "cnpapers.net" and nothing
obvious hit me.  Can you resolve remote sites quickly?  Ever
considered running DNS service on your mail machines?

Jeff Earickson
Colby College

On Thu, 12 Feb 2004, Steve Campbell wrote:

> Date: Thu, 12 Feb 2004 21:33:15 -0500
> From: Steve Campbell <campbell at CNPAPERS.COM>
> Reply-To: MailScanner mailing list <MAILSCANNER at JISCMAIL.AC.UK>
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Re: Preference for batch sizes
>
> Mr. Hooton,
>
> Thank you for a very informative response. I am seeing some really strange
> things happening here, as I have alluded to in prior post with this subject. I
> will more than likely have to start using tempfs for some things, but first I
> will break up our domains across multiple boxes.
>
> The strangeness of no timeouts for RBL and SA as a general rule, small amounts
> of mail in incoming taking a very long time to clear, and the load average
> dropping regardless of what is in either queues has me baffled. Especially,
> since before Tuesday night, large amounts of email being dumped into this
> server was handled very swiftly. Load average usually remained proportionate
> to emails waiting to be scanned or delivered.
>
> One other thing I am going to do is wean myself away from linuxconf and begin
> using sendmail to it's fullest. (Be warned - Another post coming to either
> this list or some other). I really have a problem with non-existent user
> email. I feel it's a shame to waste resources just to eliminate bounces, but I
> have yet to find how these are resolved by Sendmail.
>
> Thanks very much
>
> Steve Campbell
>
>
> Quoting David Hooton <david at PLATFORMHOSTING.COM>:
>
> > > -----Original Message-----
> > > From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK] On
> > > Behalf Of Stephe Campbell
> > > Sent: Friday, 13 February 2004 3:55 AM
> > > To: MAILSCANNER at JISCMAIL.AC.UK
> > > Subject: Re: Preference for batch sizes
> > >
> > > I do not use Razor, but the suggestion to lower the message count per scan
> > > seemed to fix it up. I am not running at 2 or 3 messages in my incoming.
> > > Somehow, I missed the prior thread.
> > >
> >
> >
> > Hi Steve,
> >
> > I've found on an i386 box with 1 gig of ram, 80 Gig 7200RPM IDE disk and an
> > AMD 2200 processor, using tempfs for the work dir that 3 children and 10
> > messages per batch is the most efficient combination.
> >
> > If you have an evening free, write yourself a script to flood the box with a
> > decent number of messages and do some timings on how long each combination
> > takes to clear the queue - results below.
> >
> > Spam Load Test
> >
> > Messages        Children        Msg/batch       Mins
> > 50              4               5               0:08:39 Workdir = DISK
> > 50              3               5               0:08:05 Workdir = DISK
> > 50              3               10              0:09:38 Workdir = DISK
> > 50              2               10              0:13:07 Workdir = DISK
> > 50              1               10              0:17:00 Workdir = DISK
> > 50              0               10              0:15:00 Workdir = DISK
> > 50              3               5               0:01:51 Workdir = TEMPFS
> > 50              3               10              0:01:02 Workdir = TEMPFS
> > 50              3               15              0:01:10 Workdir = TEMPFS
> >
> > We've managed to drop load on the box to 1/3 of it's old load just by
> > playing with these settings alone, and a further reduction in load after
> > that by tuning our spamassassin rules very savagely.
> >
> > We have also recently taken to storing the Bayes DB's in tempfs which has
> > helped further reduce load and improve performance.
> >
> > Hope this helps you and anyone else with these kinds of issues.
> >
> > Cheers!
> >
> > Dave
> >
> >
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>
>
>
>
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