Using dovecot Replication in a medium to large enterprise.

[Edgaras Lukoševičius]

Hi,

Replication - no, never used it, but we do use Dovecot dsync a lot.
Over a few hundred servers that is, in a "multi-million user 
installations".

There are some issues and pitfalls that are solvable, but in general it 
works.

In the sense of resource intensity I guess dsync is as intense as 
replication,
and IT IS resource intensive. Which is also solvable by process priority 
etc.

For example we are tracking the state of every mailbox dsync,
as it sometimes fails and dsync needs to be re-tried.

One of the pitfalls is that I have never managed to make Sieve 
replication to work,
so rsync-over-ssh is used for that.

In general it was pretty hard to make a RELIABLE dsync solution that works.

~500 mailboxes is not a lot, and it will require some effort to make 
everything tick,
I'm not sure if it is worth it in your case.

The PRO version has S3 driver, consider this solution too.

On 28/11/2019 09:35, Brent Clark via dovecot wrote:
> Good day Guys
>
> Just wanted to pick the communities brain and experience(s) for a second.
>
> At $CORP where I work. My team has inherited a single server mail 
> solution.
>
> We need to look to building a standby / replicated solution.
>
> One of the things we were looking at is 
> https://wiki.dovecot.org/Replication
>
> We have in excess of +/- 500 mail boxes and using just under 1TB of 
> disk space. That is a lot of small files.
>
> Reading about this plugin / module, things that stick out and is 
> concerning is the comments:
>
> "The replication in general is a bit resource intensive, so it's not 
> recommended to be used in multi-million user installations."
>
> "WARNING: Shared folder replication doesn't work correctly right now –"
>
> I would like to ask the community (and anyone else in a similar 
> enterprise) how and if this solution works and scales.
>
> In short, I am asking, is anyone else using Dovecot Replication in a 
> medium to large enterprise?
> Can you please share your experiences, pitfalls and if you have any 
> tips managing mail replication.
>
> Kindest regards and thanks in advance.
> Brent Clark