FBSD 6.2 Xeon 2.4ghz CPU and high load

DAve dave.list at pixelhammer.com
Fri May 9 21:30:00 UTC 2008

Chuck Swiger wrote:
> On May 9, 2008, at 11:55 AM, DAve wrote:
>>> For single-processor systems, FreeBSD 4.11 does very well at a lot of 
>>> tasks.  However, Dave apparently has a 4-CPU system (~8 threads if he 
>>> enabled hyperthreading), and for real SMP hardware, more recent 
>>> versions of FreeBSD generally perform better than 4.x would.
>> Single CPU quad core.
> OK.
>> ps -aux output is up, look under the FBSD dir. I also put up both 
>> dmesg.boot files from the servers.
> MailScanner is what is taking up all of the load; tuning that area is 
> where you need to focus.
> Things which come to mind are trying to limit the max number of children 
> of that being run to something smaller, perhaps 8 or so.  Yes, they 
> recommend running 5 * #CPUs, but they also think their instances are 
> going to be around 20MB in size, but yours are running at 100+ MB size.
> You might find that running sa-update and sa-compile nightly might 
> improve your SpamAssassin performance; I've got a crontab setup which 
> runs the following nightly:
> % cat /usr/local/bin/update-spamassassin
> #! /bin/sh
> PATH=$PATH:/usr/local/bin
> sa-update --allowplugins --gpgkey 
> D1C035168C1EBC08464946DA258CDB3ABDE9DC10 --channel 
> saupdates.openprotect.com --channel updates.spamassassin.org
> sa-compile
> kill -HUP `cat /var/run/vscan/spamd.pid`
> (If you aren't running spamd because MailScanner uses builtin interface 
> to SpamAssassin, comment out the last line.  But do check the sa-compile 
> docs, you have to make a change for it to be used....)
> Regards,

I appologize I should have given more info.

We do run sa-update, and sa-compile. We also run 0 scores on most DNSBL 
tests as we run those at the mta level along with milter-greylist, 
milter-ahead, pipelining rejection, and greet pause. We have been 
running a very trimmed down and fine tuned system for about two years 
now with good results. I do think the upgrade to SA 3.2.4 is very heavy, 
considerably more resource usage than 3.1.8 which we were running prior 
to the OS upgrade.

I have not changed the settings for MailScanner from our previous 
install with respect to number of children or to batch size. Previous 
testing showed that 13 MS children with a batch size of 10 messages was 
optimal. I can certainly give that a try.  I will look at enabling 
Hyperthreading as well.

I've also found this, which may be a clue to the suggestion that a 
binary upgrade to 6.3 was a solution.


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