dovecot 2.2.36.4 problem with ulimit

[Maciej Milaszewski]

Hi
Limits:

Where all working fine:

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 257970
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65536
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 257970
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited


with new debian9:

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 257577
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 257577
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited


maby systemd "something has changed"

and add:

echo "kernel.pid_max = 50000" >> /etc/sysctl.conf
sysctl -p
systemctl edit dovecot.service

[Service]
TasksMax=40000
systemctl daemon-reload
systemctl restart dovecot.service

cat /sys/fs/cgroup/pids/system.slice/dovecot.service/pids.max


Any idea ?

On 16.09.2020 09:45, Maciej Milaszewski wrote:
> Hi
> I update os from debian8 to debian9
>
> # 2.2.36.4 (baf9232c1): /etc/dovecot/dovecot.conf
> # Pigeonhole version 0.4.24.2 (aaba65b7)
> # OS: Linux 4.9.0-13-amd64 x86_64 Debian 9.13
>
> All works fine but sometimes I get:
>
> Sep 16 09:17:00 dovecot4 dovecot: master: Error: service(pop3): fork()
> failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:00 dovecot4 dovecot: master: Error: service(imap): fork()
> failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:00 dovecot4 dovecot: master: Error: service(doveadm):
> fork() failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:02 dovecot4 dovecot: master: Error: service(doveadm):
> fork() failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:02 dovecot4 dovecot: master: Error: service(pop3): fork()
> failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:02 dovecot4 dovecot: master: Error: service(imap): fork()
> failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
> Sep 16 09:17:04 dovecot4 dovecot: master: Error: service(imap): fork()
> failed: Resource temporarily unavailable (ulimit -u 257577 reached?)
>
> Other dovecot is debian8 and problem not exists - any idea ?