dovecot/config processes open, and consuming all memory

[filipe at digirati.com.br]

The only thing I had initially configured was vsz_limit, but as the 
number of clients grew, the number of dovecot/config processes grew, and 
with that I added idle_kill and service_count to try to minimize the use 
of ram memory
In dovecot 2.2.33.2 , another server, has the same amount of accounts (+ 
or -30 thousand) but there is only one dovecot/config process and every 
dovecot does not consume more than 5Gb

On 16/08/2022 06:20, Aki Tuomi wrote:
>> 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