[Dovecot] IMAP-proxy or not with sogo webmail and dovecot backend

[Jan-Frode Myklebust]

We've been collecting some stats to see what kind of benefits
UP/SquirrelMail's IMAP Proxy in for our SOGo webmail users. Dovecot is
running in High-performance mode http://wiki2.dovecot.org/LoginProcess
with authentication caching http://wiki2.dovecot.org/Authentication/Caching

During the weekend two servers (webmail3 and webmail4) has been running
with local imapproxy and two servers without (webmail1 and webmail2). Each
server has served about 1 million http requests, over 3 days. 

server          avg. response time	# requests
----------------------------------------------------
webmail1.example.net   0.370411        1092386
webmail2.example.net   0.374227        1045141
webmail3.example.net   0.378097        1043919	imapproxy
webmail4.example.net   0.378593        1028653	imapproxy


ONLY requests that took more than 5 seconds to process:

server          avg. response time      # requests
----------------------------------------------------
webmail1.example.net   26.048          1125
webmail2.example.net   26.2997         1080
webmail3.example.net   28.5596         808	imapproxy
webmail4.example.net   27.1004         964	imapproxy

ONLY requests that took more than 10 seconds to process:

server          avg. response time	# requests
----------------------------------------------------
webmail1.example.net   49.1407         516
webmail2.example.net   53.0139         459
webmail3.example.net   59.7906         333	imapproxy
webmail4.example.net   58.167          384	imapproxy

The responstimes are not very fast, but they do seem to support
the claim that an imapproxy isn't needed for dovecot.


  -jf