Quota calculation with MySQL backend and replication.

[Reio Remma]

On 27.04.2020 13:21, Aki Tuomi wrote:
>> On 27/04/2020 12:35 Reio Remma <reio at mrstuudio.ee> wrote:
>>
>>   
>> On 27.04.2020 12:15, Reio Remma wrote:
>>> Hello!
>>>
>>> Over the weekend I converted our Dovecot server from Maildir quota to
>>> MySQL backed quota and then provisioned a fresh replica server and
>>> seeded it via Dovecot replication.
>>>
>>> This morning most mailboxes were over quota, reporting twice the
>>> actual usage. I'm fairly certain it's the effect of having sql backed
>>> quota with both Dovecot servers using the same database.
>>>
>>> Can anyone tell me if this is a one-off problem stemming from
>>> replicating the 2nd server from scratch or should I be aware of other
>>> quirks concerning sql backed quota and replication?
>> I see that arrived messages are also counted twice.
>>
>> Reio
> Please try using count quota with quota_clone instead.

Very nice, got it working now.

I've a suggestion for the docs pages for sql backed quota - a warning 
about using it with replication and directing us to use quota_clone plugin.

One question also - am I right that it would probably make sense to turn 
off quota_clone on one server? Otherwise I suspect they're both updating 
quota in the database, once when the 1st server receives the mail and 
then when the 2nd server receives it via replication.

Thanks!
Reio