On Thu, Jul 31, 2008 at 7:15 AM, Thomas Hummel hummel@pasteur.fr wrote:
I don't think that DNS round robin would do the trick because some UA (for instance Thunderbird) often open up to 5 connexions for the same user, unless maybe such UA makes a single 'gethostbyname()', thus connecting 5 times to the same physical server ?
I am not seeing the issue, your seeing issues with the UA spreading the connects across multiple servers? If so are the message-ids different for imap://hummel@ on one machine versus another? The same filer for a backend right?
I assume that authentication, and more, is caching on Dovecot. So the actual LDAP hits are solitary for the whole lifetime of the UA session most likely.
Dovecot as a LDA is ideal, as stated above, it will do the initial indexing upon delivery of messages and dovecot-imap will fixup as needed.
Perhaps the UUIDS for pop and imap can be looked at for speed ups.
Having a lot of processes, and in what state are they in? If the bulk of them are running because of searches (like outlook crazy queries or virus checkers than scan 1gb of mail etc) Thats a problem that is a little outside load balancing it seems.
I would see the pre-delivery being more of a issue than dovecot performance wise especially with the LDA, hefty caching, and good maildir file naming.
-- Gabriel Millerd