Dovecot 2.4 with replication support (Cernko, Patrick)

The Dovecot IMAP server up to version 2.3 included online replication support. This feature allows setting up a service with two redundant servers. Both servers hold all data of the users. As the replication works in both ways, it allows running the servers in an active-active setup. Using Dovecot's Director feature, the users' requests can be balanced on both servers.

Unfortunately the replication feature was removed in the 2.4 release. I have reintegrated the removed code of the replication feature into Dovecot 2.4.1.

I had to adopt some (few) parts to reflect changes, that where made to the APIs and interfaces. To continue support for mail_replica and noreplicate as userdb settings, I established a workaround. The code has been tested and we started using it in our production environment.

Currently the code is provided as a patch for Dovecot 2.4.1. I am working on a version, that can be provided as an extension/plugin for vanilla Dovecot.

If you want to contribute or found a bug, feel free to contact me. The code is released with the same license as Dovecot itself (MIT and LGPLv2.1 mostly), see https://doc.dovecot.org/main/license.html.

The current version can be found here:

• dovecot-replication-2.4.1.diff