On 13/02/2012 19:43, Jan-Frode Myklebust wrote:
On Mon, Feb 13, 2012 at 11:08:48AM -0800, Mark Moseley wrote:
Out of curiosity, are you running dovecot locally on those webmail
servers as well, or is it talking to remote dovecot servers?
The webmail servers are talking with dovecot director servers which in
turn are talking with the backend dovecot servers. Each service running
on different servers.
Webmail-servers -> director-servers -> backend-servers
I think the original question was still sensible. In your case it seems
like the ping times are identical between:
webmail -> imap-proxy
webmail -> imap server
I think your results show that a proxy has little (or negative) benefit
in this situation, but it seems feasible that a proxy could eliminate
several RTT trips in the event that the proxy is "closer" than the imap
server? This might happen if say the imap server is in a different
datacenter (webmail on an office server machine?)
I'm also pleased to see that there is little negative cost in using a
proxy... I recently added imap-proxy to our webmail setup because I
wanted to log "last login + logout" times. I haven't quite figured out
how to best log "logout time" (Timo, any chance of a post logout script?
Or perhaps it's possible with the current login scripting?). However,
using imap-proxy has the benefit of "clustering" logins a little and
this makes log files a little easier to understand in the face of users
with desktop mail clients plus webmail users. Possibly this idea useful
to someone else...
Thanks for measuring this!
Ed W
