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

[Jan-Frode Myklebust]

On Tue, Feb 21, 2012 at 02:33:24PM +0000, Ed W wrote:
> 
> 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?)

The webmail/imapproxy were actually running in a different datacenter to
the dovecot director/backend servers, but only about 20KM away.

Ping tests:

webmail->director:

	rtt min/avg/max/mdev = 0.933/1.061/2.034/0.183 ms

director->backend:

	rtt min/avg/max/mdev = 0.104/0.108/0.127/0.005 ms

webmail->localhost:

	rtt min/avg/max/mdev = 0.020/0.062/1.866/0.257 ms


  -jf