I set up a test server and started testing it by multiple threads (1-200), using all the advice given to me. 1 I disabled the postlogin script 2 raised maxconns to 200 3 set service_count = 400, process_min_avail = 100 4 increase auth_cache 5 increase the pool in postgres 6 enable high-performance mode for imap-login
However, the performance of the auth service seems limited by one core and cannot rise above 30-40 logins per second for our processor (60-70 with warm cache). Still, is there any way to parallelize this? Having 48 cores to be limited by the performance of the one is too sad. On Tue, Feb 4, 2025 at 1:23 PM Timo Sirainen <t...@sirainen.com> wrote: > On 3. Feb 2025, at 20.18, Anatoliy Zhestov via dovecot < > dovecot@dovecot.org> wrote: > > > >> > >> Are you sure the problem is authentication / pgsql? You could test with > >> looping "doveadm auth lookup $user" rapidly. Of course for different > users > >> to avoid them coming from cache. Or if you can reproduce it that way, > try > >> if the same happens for repeating the same user so it does come from > cache. > > > > > > i test in condition when 90% of imap connection is already established. > > auth cache is enabled so i guess tests with the same user are not > relevant. > > > > -------- less loaded server > > ps waux|grep imap-login|wc -l > > 24977 > > Oh, somehow I missed that you have this many concurrent connections. > > > echo "13285 / 343" |bc > > 38 (per second) > > So with this speed 24977 users would take 11 minutes to login back, which > is a bit slow. > > Some ideas: > > 1) If pgsql is the bottleneck, try multiple pgsql connections: Add > maxconns=4 (or whatever) to the dovecot-sql.conf.ext's connect line. > > 2) In your Dovecot proxy (assuming you have one?) you can configure it to > spread over disconnections over a long time, if the issue is that backend > disconnects everyone at once. login_proxy_max_disconnect_delay setting does > this. > > 3) With that many connections and to make logins faster, you'd be better > off using > https://doc.dovecot.org/2.3/admin_manual/login_processes/#high-performance-mode > > 4) To optimize login performance, it would be best to get rid of the > post-login script. Also: > > service imap { > service_count = 1000 > process_min_avail = 10 > } > > 5) auth_cache_size is rather small. Likely could be increased much larger. _______________________________________________ dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-le...@dovecot.org
