On Fri, Nov 02, 2007 at 05:52:49PM +0200, Timo Sirainen wrote:
On Fri, 2007-11-02 at 15:05 +0100, Geoffroy Desvernay wrote:
We are using dovecot for some times (a little before 1.0), for IMAP and (a little for the moment) deliver.
We have ~20000 logins/day, Maildirs are over NFS (with indexes too, for the moment...)
With more than one server accessing the same maildir at around the same time? See "attribute cache problems" (and the rest of the page as well) in http://wiki.dovecot.org/NFS
I'll bite, I keep hearing mention of "each user is assigned a specific computer which is used whenever possible" and I'm willing to try it out so my indexes are safe. The part where I get stuck is the "whenever possible".
I've looked at using perdition and/or dovecot, but both seem only offer a single IP to connect to per user, and the only workarounds I've heard of is to have an additional process monitor the imap servers and modify the mappings when a server is down. Is there a simpler way to have a proxy attempt a list of servers for each user?
I would just point it back at my hardware load balancer in essence, but for that to work, the server originating the connection cannot host the VIP of the target otherwise the connection will stay local since the VIP would be local (I don't have my traffic flow through the load balancer physically). I could put a bunch of "every server but me" VIPs in the LB, one for each server, but thats a messy hack. I've thought of a handful of different ways I could have the connections go through my planned 4 mail servers but none so far give me complete load balancing, automatic failover, and simple enough to make it worth trying to have only one copy of indexes.
Anyone have any input? Thanks