https://www.mail-archive.com/dovecot%40dovecot.org/msg85850.html
From: D D pierre.alletru@gmail.com
We're seeing a ton of imap-login processes running even when using high performance mode (https://doc.dovecot.org/admin_manual/login_processes/#high-performance-mode). According to the docs:
"process_min_avail should be set to be at least the number of CPU cores in the system, so that all of them will be used. Otherwise new processes are created only once an existing one’s connection count reaches client_limit"
We have process_min_avail=4, client_limit=0 and default_client_limit=200000. So we'd expect seeing only 4 imap-login processes serving a ton of connections each. Yet, we see thousands of imap-login processes (more than half of all the imap processes): ...
Is having so many imap-login processes normal with our config? Did we misunderstand the docs or is there something wrong here?
default_client_limit = 1048576 default_process_limit = 200000
service imap-login { # client_limit = 0 # default is 0 # process_limit = 0 # default is 0 service_count = 100
This service limit might be your culprit.
I wrote about the strange interaction between service_count and process_limit here:
https://www.mail-archive.com/dovecot%40dovecot.org/msg85850.html
This gotcha should really be documented.
Joseph Tam jtam.home@gmail.com