[Dovecot] dovecot director service

[Xavier Pons]

  El 08/07/2010 10:00, Oliver Eales escribió:
> Am 08.07.2010 09:31, schrieb Xavier Pons:
>>  El 07/07/2010 13:35, Timo Sirainen escribió:
>> ....
>>>> this limitation does not allow use the same two directors servers 
>>>> like mail backend servers?
>>> You can install two Dovecot instances on the same server (set 
>>> different base_dir for them), one as director and another as mail 
>>> server. A bit annoying to have two of them, but it should work.
>> I suppouse, this require to have different IPs address for every 
>> instance?
>>>> the fairlure of one director server it's automatically detected or 
>>>> require manual intervention?
>>>> It's automatically detected. I've only simulated it with software, 
>>>> but you could also try it by actually pulling the network plug out. :)
>> If I have different dovecot instances on same host, one like proxy 
>> and another like mail backend, the director service will detect both 
>> failures of
>> director service like of backend servers? or only detect the first one?
>
> You will have to build some kind of HA environment in front of the 
> proxys. If you just use DNS round-robin for connects to the proxy 
> server (the instance) client connection attempts to this particular 
> server will fail. The director service is only for user-stickyness 
> (and HA) between the 1st and the 2nd tier. Most common use would be in 
> a NFS storage backend.
>
Yes, we will have two hardware balancers in front of proxies. Thus,  the 
director service will detect failures of backend servers and not forward
sessions them? how detects if a  backend server it's alive or not?
The command 'doveadm director status', gives information about status of 
backend mailservers or of director servers?
Sorry for so many questions ...

Thanks
Xavier