[Mimedefang] Bayes locking

[Button, Shawn]

We don't scan large files. We do scan inbound and outbound but I
whitelist outbound in SA.

I restart sendmail/MD and the problem goes away for a little while, then
resurfaces. Bayes filtering has demonstrated a increase in
effectiveness.

I will look at the timeout, none of these things occurred before we
upgraded sendmail/sa/md.

Thank you,

Shawn 

-----Original Message-----
From: mimedefang-bounces at lists.roaringpenguin.com
[mailto:mimedefang-bounces at lists.roaringpenguin.com] On Behalf Of Paul
Murphy
Sent: Wednesday, October 06, 2004 10:17 AM
To: mimedefang at lists.roaringpenguin.com
Subject: RE: [Mimedefang] Bayes locking

Shawn,

Several people have reported issues with this, and after some
investigation on
my system and by trawling through the code, the whole area of database
locking
for Bayes and AWL is a mess.  What seems to be happening is that a race
condition occurs where one slave has a lock on the database, a second
slave
tries to lock the database and finds the existing lock, the second slave
decides
the lock is too old to be current, but before it can delete the lock,
the first
slave has either unlocked the file, or another slave has broken the lock
instead.

The solution is to use a proper database - the latest SA has support for
MySQL,
which will be much more stable and on large databases will also probably
be
faster.

The filter timeout in your log is more of an issue - if the filter is
not
completing scanning quickly enough, then either your timeout is set too
low, the
system is overloaded, or you are doing too much scanning.  Particularly
for
large CAD files, are you skipping virus scanning and SPAM classification
in both
directions?  I would tend to treat any message of more than about 200Kb
as
definitely not SPAM, and anything over 1Mb as highly unlikely to be a
virus, so
would skip these inbound.  Outbound, I do no SPAM checks at all, relying
on my
users being sensible and our systems being secure.

Best Wishes,

Paul.
__________________________________________________
Paul Murphy
Head of Informatics
Ionix Pharmaceuticals Ltd
418 Science Park, Cambridge, CB4 0PA

Tel. 01223 433741
Fax. 01223 433788

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