[Dovecot] Synchronization error in NFS

[Timo Sirainen]

On 14.2.2012, at 4.39, Andy YB Hu wrote:

> Another question is about the director failover. In
> http://blog.dovecot.org/2010/05/new-director-service-in-v20-for-nfs.html
> you said: "The main complexity here comes from how to handle proxy server
> failures in different situations. Those are less interesting to describe
> and I haven't yet implemented all of it, so let's just assume that in
> future it all works perfectly."   So currently there is no good way to
> handle the director failover,  or any 3rd party solution like poolmon by
> Brad Davidson for health monitoring of backend servers?

Your load balancer handles director downtimes so it connects only to directors that are up. Directors themselves figure out when one of them is down (by either explicit disconnection or timeout). That's the theory, and so far no one's told me it doesn't work that way.

For the backend servers there's still no automation though. You'll need to explicitly tell director to stop trying to connect some specific backend. The poolmon is intended for that. It would be possible to implement this directly in the director itself, but so far it hasn't really been a priority since the companies who have paid for it have wanted to implement it internally themselves..