Massive alias / bulk delivery problem

[gnd]

On 7/15/20 6:26 PM, Bernardo Reino wrote:
> On Tue, 14 Jul 2020, gnd wrote:
> 
>> [...]
>> anyway, if there is anyway how to optimize dovecot for effective
>> delivery of 20k+ emails within a few minutes, id be glad to know.
> 
> .. but in the first message you wrote:
> 
>> Are there any optimizations or ways how to design the system
>> around this problem ? Eg. is there a way how to deliver messages
>> more slowly, and spread the load over longer time ?
> 
> So it is not clear whether you want to actually deliver the messages as
> fast as possible ("effective delivery .. within a few minutes") or if
> you'd rather have the process spread over longer time.

i see how this can sound confusing. what i meant is that in the ideal
case i would sacrifice the delivery time (the mails can be delivered
within one hour not a few minutes) as long as the server load stays
'normal'. currently the delivery of 20k mails on a 2core server takes
around 90 seconds, but the load reaches a peak of ~15.

It was worse, but I have turned on these settings in Dovecot:

mail_fsync = never
maildir_very_dirty_syncs=yes

The server is still unused, so i'm afraid that under normal
circumstances (having a constant stream of IMA traffic from those 20k
users) things will be much worse.

> 
> Generally it is recommended to let the system work as fast as it can, as
> otherwise you'll just make it slower for no reason (you will use your
> resources less efficiently).

id prefer to slow down / spread the load over longer time as immediate
message delivery is not so important.. but as written earlier, im crying
on the wrong grave, as this is probably better to approach from postfix
side.

> 
> Cheers.