Timo,
On 6/24/10 4:23 AM, "Timo Sirainen" tss@iki.fi wrote:
I'd recommend also installing and configuring imapproxy - it can be beneficial with squirrelmail.
Do you have any about a real world numbers about installation with and without imapproxy?
We run imapproxy behind our Roundcube instance, and our old in-house Perl mail system has a custom equivalent written in C that also does some caching of folder metadata and message headers.
We run a proxy instance on each of the webmail hosts, with the communication between the web application add the proxy being done in cleartext, but with the proxy -> Dovecot communication secured over SSL. Besides preventing a lot of extra SSL handshakes and login/logout actions, it also helps tie a user session to a single backend node in our pool of IMAP servers. It seems like there might also be other benefits to having Dovecot not tear down all of the user session state between page loads.
A lot of this stuff might be nice to see in the Director some day. If there was an option to not immediately close the Director proxy's backend connections when the user logs out, (ie leave the connection active and logged in for X seconds, and reuse it if the user logs in to the Director again), and if the auth caching works as well as you say, then I could definitely see a day where we replace imapproxy with a director instance on the webmail host.
-Brad