[Dovecot] dsync replication available for testing

[Timo Sirainen]

On 5.3.2012, at 9.25, Attila Nagy wrote:

> On 03/04/12 11:44, Timo Sirainen wrote:
>> In dovecot-2.1 hg you can now test dsync-based replication. Everything isn't finished yet, but it appears to work and I've enabled it for my @dovecot.fi mails. Some issues:
>> 
> Do you plan to make it more performant in the future? I mean calling doveadm (and ssh) for every change -even when they are aggregated- seems to be very resource intensive, it won't keep up on a machine with a lot of modifications happening every seconds.

Sure the idea is to improve the performance :) There are two ways:

1) Use longer running SSH sessions which dsync more than one user at a time.

2) Use TCP connections instead of SSH.

> It would be good to have constantly running daemons on both sides to eliminate the high startup/teardown costs.

The process startup/teardown costs are pretty low. I'll need to improve dsync's performance at some point though. Actually I pretty much redesigned the whole dsync already, but I'll probably leave that to v2.2. The current design can still be improved.