Desperately trying to debug poor spam scanning performance

Steve Freegard steve.freegard at
Tue Sep 16 11:58:00 IST 2008

Hi Ben,

Ben Tisdall wrote:
> The razor timeout seemed to have been a one-off.
> Here's a debug output (clearly Pyzor's unhappy, but it's the same on the
> comparison machine too, turning off doesn't help)

1)  Switch-off Pyzor by commenting the loadplugin lines in v3*.pre and 
init.pre in /etc/mail/spamassassin.

IMHO - Pyzor isn't usable anymore unless you are low-volume and can put 
up with the timeouts decreasing your scanner throughput, so I always 
either don't install it or disable it.

Even though it appears to be unwell on your machines anyway - disabling 
it will prevent the need for the code to get loaded anyway.

2)  Compare like-for-like.

Currently - each machine has different version of Perl modules (some 
newer some older).  Check for updates to each of them on the new machine 
and get the latest versions.

Also - you're looking at the 'Log Speed' output on both machines and 
because they are showing different lower numbers you're jumping to the 
conclusion that something is wrong.... it could be - but the only way to 
be certain is to process the *same* batch of messages on both machines 
(without any other traffic running at the same time) and then comparing 
the results.

I'd expect the bytes throughput shown in the logs to vary greatly for 
each batch due to the fact that some messages are larger and more 
complex than others, so unless you are running the same batches through 
- then you can't really know for sure that one is slower than the other.

3)  Do you have anything configured in 'Spam Lists' or 'Spam Domain 
List' on either machine in MailScanner.conf??

4)  Have you mounted /var/spool/MailScanner/incoming on tmpfs?

Kind regards,

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