Many users are reporting that spamd occationally goes into a 100% cpu usage loop which doesn't stop until completely killed and restarted. The problem is mainly reported with Ensim, but since the SpamAssassin (SA) version used by Ensim is generic it could probably happen for other platforms as well.

It appears this is caused by SA's Bayes subsystem, and by disabling Bayes we have found the problem so far to have disappeared. The Bayes subsystem is just one of a range of checks applied by SA so while there is a small loss of functionality it's minor and at least the rest works.

Howto fix the problem:

1) Edit /etc/mail/spamassassin/local.cf using vi or pico or whatever editor you prefer.
2) Add one line:
use_bayes 0
3) Exit and save
4) Stop SA (service spamassassin stop)
5) Kill any looping jobs (killall -9 spamd)
6) Start SA (service spamassassin start)

An issue that could be causing it is you need to rebuild your bayes DB every so often... So you might want to setup a nightly cronjob if you aren't using it in conjunction with a more recent version of MailScanner.

Also if you upgrade you need to rebuild it, and depending on which version some are not upgradeable I think.

The Bayes analysis really adds a lot of functionality for me, You can lower the required spam/ham #'s to about 20 to get your bayes kickstarted.

we tracked our problem down to a full e-mail account, heh (the one the site admin set for catch-all) adding more space to the account limit seems to have fixed it

hi, i face a similar problem. when i run top, i can see user #22576 using up 99% cpu.

how do i trace #22576? how do i know this user# belongs to which actual email user?

pls help

Try to use greylisting to reduce mail checked by spamd.

Regards,
Netino

Happened to me too on a new Ensim 10.1 from EV1. Disabling Bayes stopped it.

Mail load at the door was about 2 per second.

Mail load for Spamd was only about 1 a minute - Not a lot of work, as I was blocking using dnsb sorbs and more, VERY aggressively rejecting hardcore spam before it even got to mailscanner and sendmail.

New server, so I can;t see bayes needign a rebuild being the problem.

Killing bayes took my load from 6 to about 0.1 !

Cian

sorry wrong number