[horde] High Capacity Horde & Email Environment

[Etienne Goyer]

On Tue, Mar 30, 2004 at 08:49:57PM -0400, Jeff Warnica wrote:
> On Tue, 2004-30-03 at 16:02 -0600, Jacob Davida wrote:
> > Since each Postfix server would have Courier on it, users could POP or IMAP
> > data from
> > any of the servers, which in turn would pull the email out of the necessary
> > NFS mount.
> > Are we all on the same page? Let me know if I've lost anyone.
> 
> I'm partial to Cyrus. With it's Murder system (which I haven't used),
> the front end box(es) cleanly proxy IMAP/POP to the right storage
> system. LMTP injection too for that matter. You would be able to
> completely disassociate MXing with storage. Note that this provides
> clustering for (horizontal) scalability only - not for reliability. To
> quote them "Note that Cyrus Murder is still relatively young in the
> grand scheme of things, and if you choose to deploy you are doing so at
> your own risk.". OTOH, you are comparing it to a custom solution. That
> Cyrus is a "magic box" may or may not be a good thing. Tight integration
> with Sieve may or may not be a good thing. It can inherently understand
> virtual domains, which almost definitely is a good thing.

We do large scale (70K accounts last time I checked) Horde with Cyrus 
Murder.  We present a single image to client by using LVS.  Horde
preference are kept in a single database that is accessed by each
frontend (two of them).  So far, Horde have been trouble free in this
setup.  We had some major problem with the Murder, but nothing someone
careful could not avoid.

So far, the performance exceed my expectation.  I thought the frontends
would melt from being used by so many accounts, but so far they are 
holding thight serving IMAP/POP, Horde/IMP and doing MTA duties.

This setup provide very good scalability as we can add as many frontend
as required and the load would be distributed pretty evenly.  It is not
entirely fault-tolerant as it does still have two single
point-of-failure : the MySQL database for Horde prefs and the MUPDATE
master (the Cyrus Murder controlling, if you want).

I have not read the original post entirely, so if M. Davida have more
specific questions about our setup, please go ahead.

-- 
Etienne Goyer                    Linux Québec Technologies Inc.
http://www.LinuxQuebec.com       etienne.goyer at linuxquebec.com