Hi,

we have running a similar setup for some years now (IMAP + POP3).

• frontend imap+pop3 proxy (imap.mydomain.com)
• multiple backend servers
• each backend is responsible for a few domains (ex. domains beginning with a-f, g-l, and so on)

Database setup:

• 3 MySql Servers in a Master/Slave configuration:
  • 1 Master, where user, password and proxy information are stored.
  • 2 Slaves, each dovecot backend and the frontend proxy is configured to read the user configuration from the same database.
  • the 2 slaves helps us to keep away the mysql select queries from our master server. But depending on your workload, perhaps one central mysql server without slaves is enough.

For proxying requests to the correct backend server see: https://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy

In our setup the frontend proxy does only check if the user exists. If yes, the request will be forwarded to the correct backend and "real" authentication will be performed there.

Best Urban Loesch

Am 03.10.2018 um 15:42 schrieb Alexandre Ellert:

Hi,

I've got no answer.. Can someone please help ?

Thank you.

Alex

Le mar. 18 sept. 2018 à 22:55, Alexandre Ellert mailto:ellertalexandre@gmail.com> a écrit :

Hi,

I'd like to achieve the following setup whit dovecot using multiple servers :
- one server dedicated to all client IMAP (TLS) connections (i <http://mail.numeezy.com>map.mymaindomain.com <http://map.mymaindomain.com>, see
below )
- each backend server has it's own local storage. no replication
- each backend server responsible of a few domains
- each backend server has it's own Mysql local database for user's passwords.

                                                        ===> Server 1 : domains A, B and C

====> i <http://mail.numeezy.com>map.mymaindomain.com <http://map.mymaindomain.com>  ===> Server 2 : domains D, E and F
              (143 TLS / 993 SSL)
                                                         ===> Server 3 : domains G, H

For example, if a user connects from domain E to i <http://mail.numeezy.com>map.mymaindomain.com <http://map.mymaindomain.com>, will Dovecot be
able to use password database hosted on Server 2 ?

Thank you !

Alex