Re: [exim] Mail with thousands recipients takes exponential …

Am 12.03.21 um 08:27 schrieb Andrew C Aitchison via Exim-users:
>
>> Any ideas what's happening here ?
>
> The increasing delays remind me of the delays for failed logins.
> Is there some sort of authentication, or similar pam or SMB access,
> to check the existence of each recipient ?
>

i made a test mail with 3000 recipients in CC.

Exim is increasing it's CPU Usage the more recipients are used until
100% CPU Core usage is reached:


    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM TIME+ COMMAND
1378404 root      20   0   66084  55300  10632 R  98,7   1,1 8:59.99
/usr/sbin/exim -Mc 1lKd2y-005m5p-3V


I have a static linear timeframe from one recipient to another appearing
in the log file, once the actual delivery from thunderbird ended.
strace says, it's due to my SQL select i use. it would go faster if the
SQL result would be cached, instead of repeating itself.

Conclusion:

a) the ( recipient ) listfunction in exim needs a redo, to improve
performance.

This is a very basic list optimization problem, you learn in data
structures at the university.

b) the setup in question has an additional problem, increasing the time
exponential .

because the core is reaching 100%, it's at it's max.. at that point,
things slow down even more.

c) time to make exim multi-threaded

best regards,
Marius