cannot login to imap under load

[Gerard Ranke]

Hi Steffen,

On 29-03-17 12:38, Steffen Kaiser wrote:
> On Tue, 28 Mar 2017, Gerard Ranke wrote:
> 
>> dovecot: master: Error: service(imap): fork() failed: Resource
>> temporarily unavailable
>> dovecot: master: Error: service(imap): command startup failed,
>> throttling for 2 secs
> 
> check out the ulimits for the Dovecot process.
> 
> -- Steffen Kaiser

Here they are:

dovecot at mail:~> ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 256942
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 10000
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) 256942
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

This looks ok to me, but on startup, I still get:

dovecot[9309]: Warning: fd limit (ulimit -n) is lower than required
under max. load (1024 < 10000), because of service auth { client_limit }

Strange thing is that dovecot still complains about the fd limit being
1024, while I set it to 10000. And how can a ulimit be too low 'because
of service auth'? I don't get that at all. Thanks for your interest!

gerard