[Dovecot] Newbie questions: Load-balanced Dovecot with NFS storage

[bhayden at umn.edu]

On Mar 2 2007, Mike Brudenell wrote:

>Thankfully this shouldn't be an issue for us.  We use the University  
>of Cambridge's "Prayer" webmail software.  Rather than being  
>something you run under a web server such as Apache it's actually a  
>custom-written HTTP to IMAP gateway and so gives a number of very  
>special benefits:
>
>   * Persistent browser-to-gateway sessions (where supported)
>   * Persistent gateway-to-imap-server sessions
>   * Aggressive caching
>   * GZipping of data en route to browser (benefits slow connections)
>
>It is VERY speedy to use: a number of our users have been impressed,  
>even when working at the end of a slow dialup link around the world  
>from us in Australia.

I'll concur with this note about Prayer. We have a very similar overall 
setup, including Prayer as one of our two Webmail offerings--on a normal 
day, it bears over half our user load (something like 35K out of 65K users, 
with ~8.5K peak concurrent sessions). The interface is heavily modified, 
but the guts are still Prayer. In our tests it, frankly, bested any other 
similar free product by a good margin (with the exception of the University 
of Oregon's AlphaMail).

To get back on topic, we were suffering from the 256-file-descriptor issue 
under Solaris 10 (with all IMAP/POP3 connections SSL-only), and I can 
confirm that it is fixed in recent RCs. We're currently ramping up the user 
count on our initial Dovecot system and so far it is going smoothly.

-Brian Hayden
OIT Internet Services 
University of MN