Too many wait in auth process

[itanguy at univ-brest.fr]

>> On 8. Feb 2022, at 12.27, itanguy at univ-brest.fr wrote:
>>
>> service auth-worker {
>>    client_limit = 1
>>    idle_kill = 0
>>    process_limit = 6000000
>>    process_min_avail = 0
>>    service_count = 1
>>    vsz_limit = 18446744073709551615 B
>> }
> What dovecot version is this? with 2.3.17 or later you should probably use service_count=0 here.
>
> That would prevent auth-worker process from dying after each authentication and then need for new process to be spawned for each authentication.

Yes, it is 2.3.17.
I give a try, it's slighty better. There is a little fewer stalled auth 
processes.
But I didn't manage to go more than 2000 clients although in production 
it's more than 8000 connections.
Maybe, it's because I didn't find how to make persistent connections 
with imaptest and there was too many login/logout. I use delay to make 
client during around 5 seconds

So I increase this delay up to 120s, this slow down login/logout and 
decrease processes stuck in wait auth queue.

I think I will go this way to simulate normal load on this server.
But that doesn't simulate a reboot of service while clients are connected.

Thank you all,
Ismaël