Debugging and resolving high loadavg when running MailScanner
Your-First-Name Your-Last-Name
borda at NETWALL.COM.BR
Wed Feb 16 13:46:20 GMT 2005
[ The following text is in the "iso-8859-1" character set. ]
[ Your display is set for the "US-ASCII" character set. ]
[ Some characters may be displayed incorrectly. ]
Just for information. I had high cpu usage and high load average and I found the problem
was in mailscanner-mrtg process. Upgrading mailscanner-mrtg solved my problem.
[]s Borda.
> Excuse me, but why are you "hung up" on loadfactor as a performance
> meter?
> It is just the average run queue size (averaged over 1, 5 and 15
> minutes), and as such is meant
> to vary.
>
> You say you have a 2 CPU system, in which case (with a "SMP capable"
> kernel) you'd be fine
> with anything up to 2 in a "sustained load" (meaning more than in
> transient peaks).
>
> Add to this that processes in "non-interruptible wait" (usually for IO
> resources) add an unconditional
> 1 (one) each, it is not at all surprising that the load goes a bit
> beyond your "CPU count" when you
> have a larger batch of messages coming in.
>
> Unless you perceive true slowdowns, you don't really have a problem with
> that.
>
> Now, the swap bit _could_ be an indicator of true problems... You say
> you use it for other things than
> as a mailhub... So you might be in a slightly memory starved state,
> easily determined via vmstat or sar,
> if you have a fair amount of ongoing swapping.
> But using swap on a system that runs for an extended period of time is
> usually not an indicator of
> problems in and of itself, it is the actual moving to/from swap of
> frequently used memory slices that'll
> be a killer.
> If you can determine that you have this situation, you have only two
> venues: reduce the RAM usage
> (by reducing what the machine does), or add more RAM.
>
> Nothing you've said so far indicate that you do have a problem... Does
> the machine occasionally
> slow down in a perceptible and measurable way? Does MailScanner report
> huge batches?
>
> I'd like to recommend the excellent "swordfish book" from o'rielly
> (Systems performance tuning).
> Even though it is geared toward Solaris primarily and linux (2.4)
> secondarily, it has a lot of general
> good tips (and tool usage tips that are rather generic for most unices).
>
> -- Glenn
>
> -----Original Message-----
> From: MailScanner mailing list
> [mailto:MAILSCANNER at JISCMAIL.AC.UK] On Behalf Of Richard Curtis
> Sent: den 16 februari 2005 13:04
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Re: Debugging and resolving high loadavg when running
> MailScanner
>
>
> I am not using either... running
> spamassassin -D --lint -p
> /etc/MailScanner/spam.assassin.prefs.conf says there are two problems -
> but the two problems appear to be that razor and pyzor are not
> installed..
>
> The load is sitting at around 0.5 at the moment - but when I was
> looking about 5 minutes ago it shot to 5.0 when a large batch of email
> came in.
> I am wondering if I need to do something with the number of
> children. I currently have it set to 10 - based on the reccomendation
> of 5 per cpu.
> The other thing I think might be related to my problems are the
> fact that the system is using a fair amount of swap - would that
> contribute to the load ?
>
> Rich
>
> Are you using razor or pyzor in that setup and does
>
> spamassassin -D --lint -p
> /etc/MailScanner/spam.assassin.prefs.conf
>
> show any problems with either of these?
>
> If so,
>
> razor-admin -discover
> pyzor discover
>
> might be useful (I've put them in a cron job here).
>
> Cheers,
>
> Phil
>
> ----
> Phil Randal
> Network Engineer
> Herefordshire Council
> Hereford, UK
>
>
>
> _____
>
> From: MailScanner mailing list
> [mailto:MAILSCANNER at JISCMAIL.AC.UK] On Behalf Of Richard Curtis
> Sent: 16 February 2005 11:33
> To: MAILSCANNER at JISCMAIL.AC.UK
> Subject: Debugging and resolving high loadavg
> when running MailScanner
>
>
> Hi All,
> I have been running MailScanner (Version
> 4.35.11) for some time, but over the last 2 -3 weeks, my loadavg has
> gone from ~0.10-0.20 to as high as 4. This may not seem high to some,
> but as I have other services on this box I want to try to reduce the
> load.
> The box runs httpd, sendmail/MailScanner with
> clamav, radius and pop. There are multiple hosted domains on the
> server.
> The box is a dual AMD Athlon MP 1200 with 512MB
> RAM.
>
> All mail is scanned through MailScanner for
> virus's, but only a small number of the domains (low traffic ones) have
> SpamAssassin enabled in MailScanners configs.
> I have to admit that I am a bit confused by some
> of the MailScanner config options - for example, the effects of "Deliver
> In Background = yes" and "Delivery Method = batch".
>
> By setting the delivery method to queue, what
> kind of impact on delivery time can I expect ? Will this have a
> significant effect of lowering the load ?
>
> One other question, I note from looking through
> the logs, I see entries like:
> Feb 16 11:25:32 lancelot MailScanner[7544]: New
> Batch: Scanning 1 messages, 1720 bytes
> Feb 16 11:25:32 lancelot MailScanner[7544]: MCP
> Checks completed at 1720 bytes per second
> Feb 16 11:25:32 lancelot MailScanner[7544]: Spam
> Checks completed at 1720 bytes per second
>
> Now what confuses me here is that I have MCP
> checks and Spam checks set to off for this mail domain - so why are the
> checks happening ?
>
> Any suggestions on performance tuning of
> MailScanner, or possible sendmail config tweaks would be greatly
> appreciated.
>
> Regards
>
> Richard
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.300 / Virus Database: 265.8.8 -
> Release Date: 14/02/05
>
>
> ------------------------ MailScanner list
> ------------------------
> To unsubscribe, email jiscmail at jiscmail.ac.uk
> with the words:
> 'leave mailscanner' in the body of the email.
> Before posting, read the MAQ
> (http://www.mailscanner.biz/maq/)
> and the archives
> (http://www.jiscmail.ac.uk/lists/mailscanner.html).
>
> Support MailScanner development - buy the book
> off the website!
>
> ------------------------ MailScanner list
> ------------------------
> To unsubscribe, email jiscmail at jiscmail.ac.uk with the
> words:
> 'leave mailscanner' in the body of the email.
> Before posting, read the MAQ
> (http://www.mailscanner.biz/maq/)
> and the archives
> (http://www.jiscmail.ac.uk/lists/mailscanner.html).
>
> Support MailScanner development - buy the book off the
> website!
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Anti-Virus.
> Version: 7.0.300 / Virus Database: 265.8.8 - Release
> Date: 14/02/05
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.300 / Virus Database: 265.8.8 - Release Date:
> 14/02/05
>
>
> ------------------------ MailScanner list
> ------------------------
> To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
> 'leave mailscanner' in the body of the email.
> Before posting, read the MAQ (http://www.mailscanner.biz/maq/)
> and the archives
> (http://www.jiscmail.ac.uk/lists/mailscanner.html).
>
> Support MailScanner development - buy the book off the website!
>
>
> ------------------------ MailScanner list ------------------------
> To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
> 'leave mailscanner' in the body of the email.
> Before posting, read the MAQ (http://www.mailscanner.biz/maq/) and
> the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).
>
> Support MailScanner development - buy the book off the website!
>
------------------------ MailScanner list ------------------------
To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
'leave mailscanner' in the body of the email.
Before posting, read the MAQ (http://www.mailscanner.biz/maq/) and
the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).
Support MailScanner development - buy the book off the website!
More information about the MailScanner
mailing list