dovecot/config processes open, and consuming all memory

[Aki Tuomi]

> On 16/08/2022 03:40 EEST Joseph Tam <jtam.home at gmail.com> wrote:
> 
>  
> > 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>

The *default* configuration for service config is usually just fine. Is there some reason you decided to modify it in first place?

Aki