<!doctype html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<div>
<br>
</div>
<blockquote type="cite">
<div>
On 14/07/2020 10:52 gnd <<a href="mailto:gnd@itchybit.org">gnd@itchybit.org</a>> wrote:
</div>
<div>
<br>
</div>
<div>
<br>
</div>
<div>
Hello list,
</div>
<div>
<br>
</div>
<div>
we are experimenting with using Dovecot as part of a simplified mail
</div>
<div>
stack with SQL for a internal messaging / notification system for our
</div>
<div>
customers. Sometimes we need to send a message to thousands of customers
</div>
<div>
at once and we do it by having aliases resolve to 10k and 20k+ mail
</div>
<div>
accounts.
</div>
<div>
<br>
</div>
<div>
When we send such a message the server load (obviously) is very high for
</div>
<div>
a few minutes (in case of an alias containing 10k addresses its around
</div>
<div>
6-7 minutes for a 2 core machine with load around 20-30).
</div>
<div>
<br>
</div>
<div>
Are there any optimizations or ways how to design the system around this
</div>
<div>
problem ? Eg. is there a way how to deliver messages more slowly, and
</div>
<div>
spread the load over longer time ?
</div>
<div>
<br>
</div>
<div>
The stack is very simple with Postfix receiving the messages and Dovecot
</div>
<div>
acting as a LMTP and IMAP server. Mailboxes are in the Maildir format on
</div>
<div>
disk. Customers get the messages on login, a PHP script connects to the
</div>
<div>
mail account associated with their ID via IMAP and sends unseen messages
</div>
<div>
in the form of a JSON.
</div>
<div>
<br>
</div>
<div>
Best regards,
</div>
<div>
<br>
</div>
<div>
gnd/
</div>
</blockquote>
<div class="default-style">
<br>
</div>
<div class="default-style">
Can you provide output of doveconf -n?
</div>
<div class="default-style">
<br>
</div>
<div class="default-style">
Also, verbose_proctitle=yes gives more insight what the processes are doing.
</div>
<div class="default-style">
<br>
</div>
<div class="default-style">
Aki
</div>
</body>
</html>