[Dovecot] quick question

[Brandon Davidson]

David,

On 1/22/10 12:34 PM, "David Halik" <dhalik at jla.rutgers.edu> wrote:
> 
> We currently have IP session 'sticky' on our L4's and it didn't help all
> that much. yes, it reduces thrashing on the backend, but ultimately it
> won't help the corruption. Like you said, multiple logins will still go
> to different servers when the IP's are different.
> 
> How if your webmail architecture setup? We're using imapproxy to spread
> them them out across the same load balancer, so essentially all traffic
> from outside and inside get's balanced. The trick is we have an internal
> load balanced virtual IP that spreads the load out for webmail on
> private IP space. If they were to go outside they would get NAT'd as one
> outbound IP, so we just go inside and get the benefit of balancing.

We have two webmail interfaces - one is an old in-house open-source project
called Alphamail, the new one is Roundcube. Both of them point at the same
VIP that we point users at, with no special rules. We're running straight
round-robin L4 connection distribution, with no least-connections or
sticky-client rules.

We've been running this way for about 3 years I think.. I've only been here
a year. We made a number of changes in sequence starting about three and a
half years ago - Linux NFS to Netapp, Courier to Dovecot, mbox to Maildir+,
LVS to F5 BigIP; not necessarily in that order. At no point have we ever had
any sort of session affinity.
 
> That's where we are, and as long as the corruptions stay user invisible,
> I'm fine with it. Crashes seem to be the only user visible issue so far,
> with "noac" being out of the question unless they buy a ridiculously
> expensive filer.

Yeah, as long as the users don't see it, I'm happy to live with the messages
in the log file.

-Brad