dovecot/config processes open, and consuming all memory

[Joseph Tam]

> I'm having strange behavior in dovecot 2.3.16.
> It's opening dozens of dovecot/config process and consuming all server
> memory. Normally each process consumes between 700Mb and 1Gb of ram.
>
> Would anyone have an idea about this?
>
> service config {
>    vsz_limit = 2048M
>    idle_kill = 60s
>    service_count = 1024
> }

Not sure it's related, but if you have service_count not 0 or 1, there
is a strange interaction
with other limits that could cause processes to hang around.  My
description of problem

    https://www.mail-archive.com/dovecot%40dovecot.org/msg85850.html

Your situation is slgihtly different (service not imap_login, and
idle_kill timeout should reduce
lingering processes that caused my problem), but try setting
service_limit to either 0 or
1 and see if your problem goes away, or gets worse.

You can also see how many file descriptors are being held by the
config process, and
see the behaviour over time (e.g. monitor /proc/{pid}/fd/*); maybe
that will give you a clue
as to what the config process is doing.

Joseph Tam <jtam.home at gmail.com>