On 07/19/2023 2:54 PM MDT Michael Grimm via dovecot <dovecot@dovecot.org> wrote:

Michael Slusarz via dovecot <dovecot@dovecot.org> wrote:

On 07/18/2023 9:00 AM MDT Gerald Galster <list+dovecot@gcore.biz> wrote:

While I understand it takes effort to maintain the replication plugin, this is especially problematic for small active/active high-availability deployments.

To clarify: replication absolutely does not provide "active/active".  Replication was meant to copy data to a standby server, but you can't have concurrent mailbox access.  This is why directors existed.

That simply isn't true, and I am baffled that you don't know that replication works with a two server active/active setup for years now! Two separate instances (active/active) on two different continents are a completely reliable failover scenario for years now.

Very irritating to read such a statement.

You may be irritated, but my statement is accurate.

Eventually consistent replication is *NOT* active/active.  active/active has a very specific meaning (and is not the same as master/master).

Quotas and shared mailboxes are two troublesome concepts with replicator.  Inconsistent mailbox views are a call center driver.  Neither of these would be an issue in a true active/active setup.  Forcing a user to a single node at any given time will prevent some (but not all) issues.

Replicator's scaling issue can't really be worked around, and was a main driver why Dovecot Pro was developed (example: one Pro customer migrating from CE/replicators saw a 90% decrease in server count).

Your positive individual experience does not change the inherent characteristics, and limitations, of the design.  If your setup works for you, in your particular circumstances, great!  But it doesn't work for everyone.  There is a reason Dovecot development moved on from replicator based architecture 10+ years ago.