[Sysadmins] падения апача под нагрузкой

[Anton Gorlov]

С недавнего времени стал падать апач. В лог ругается

[Wed Dec 23 18:29:04 2009] [alert] (11)Resource temporarily unavailable: 
setuid: unable to change to uid: 111
[Wed Dec 23 18:29:05 2009] [alert] (11)Resource temporarily unavailable: 
setuid: unable to change to uid: 111
[Wed Dec 23 18:29:05 2009] [alert] (11)Resource temporarily unavailable: 
setuid: unable to change to uid: 111
[Wed Dec 23 18:29:05 2009] [alert] Child 31272 returned a Fatal error... 
Apache is exiting!
[Wed Dec 23 18:29:05 2009] [emerg] (43)Identifier removed: couldn't grab 
the accept mutex
[Wed Dec 23 18:29:05 2009] [emerg] (43)Identifier removed: couldn't grab 
the accept mutex
[Wed Dec 23 18:29:05 2009] [emerg] (43)Identifier removed: couldn't grab 
the accept mutex

getent passwd | grep 111
syslogd:x:105:111::/dev/null:/dev/null
apache2:x:111:118:Apache2 WWW server:/var/www/apache2:/dev/null


Думал что возможно не хватает numproc -  увеличил значение до:

apache2  soft    nproc  8192
apache2  hard    nproc  8192

не помогло. Во что ещё может упираться?
В open files ?   (1024)


В настройках сервера
<IfModule mpm_prefork_module>
	StartServers         40
	MinSpareServers      10
	MaxSpareServers      1800
	ServerLimit	     2000
	MaxClients          1700
	MaxRequestsPerChild  80
</IfModule>


su - -s /bin/sh -c "ulimit -a" apache2
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 56832
max locked memory       (kbytes, -l) 32
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) 16384
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited