[Noisebridge-discuss] IMAP replication

[Asheesh Laroia]

I've become interested in working on multi-master replication for IMAP 
mail servers. The IMAP spec makes this complicated, but not impossible. 
Multi-master replication means that there are many servers that a client 
can connect to, and any action (such as adding a mail to a mailbox, or 
marking a mail as read) can be done at any server; the servers handle 
synchronization, *even if they're offline*.

As it happens, my interest in this is entirely non-commercial. I'm 
interested in adding it to the open source Dovecot IMAP server, or at 
least writing an external tool that give Dovecot this power.

Anyone want to collaborate on this? I can definitely teach you the 
relevant bits of what I know about email and IMAP; if you'll help, I think 
we can achieve a working demo of the core replication algorithm in a week 
or two.

Multi-master replication is exciting because it provides (at least) (1) a 
principled, efficient way to synchronize my laptop with my mail server, 
even when my laptop goes offline, and (2) a way to create a fast local 
mirror of a remote IMAP server.

I've chatted with Tv (of gitosis) and Timo (of Dovecot) about this, and I 
think we should start from the Dovecot replication strategy 
<http://dovecot.org/list/dovecot/2008-April/030356.html>. It's not a fixed 
document, nor is it even complete, but it describes the consensus among us 
and others on the Dovecot list.

As far as I know, there are zero publicly-available implementations of 
this sort of high-availability, multi-master IMAP replication.

-- Asheesh.

-- 
Q:	What's yellow, and equivalent to the Axiom of Choice?
A:	Zorn's Lemon.