Aegir/OpenAtrium site crashing out of memory. Help?
I have a 768 Linode on a CentOS LAMP running Drupal Aegir with just 3 Open Atrium sites, and about 10-20 concurrent users. At random times, it pukes Out of Memory kill. I can't figure out what's causing it. I'm not sure if i need to do some memory usage tweaking on my CentOS LAMP stack. I need to get this under control quickly or management is going to kill this project.. After a couple hours of a crash and burn OOM, here's some info. To my eye, it doesn't look like anything is wrong.
First the ugly OOM output
ck:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? y es lowmem_reserve[]: 0 700 754 754 Normal free:5060kB min:3348kB low:4184kB high:5020kB active_anon:339984kB inactive_anon:340208kB act ive_file:0kB inactive_file:0kB unevictable:1408kB isolated(anon):0kB isolated(file):0kB present:7172 88kB mlocked:1408kB dirty:0kB writeback:0kB mapped:604kB shmem:28kB slab_reclaimable:7776kB slab_unr eclaimable:8448kB kernel_stack:1128kB pagetables:4404kB unstable:0kB bounce:0kB writeback_tmp:0kB pa ges_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 0 428 428 HighMem free:116kB min:128kB low:192kB high:256kB active_anon:17624kB inactive_anon:17932kB active_f ile:0kB inactive_file:0kB unevictable:3136kB isolated(anon):0kB isolated(file):0kB present:54868kB m locked:3136kB dirty:0kB writeback:0kB mapped:3080kB shmem:0kB slab_reclaimable:0kB slab_unreclaimabl e:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:2 all_ unreclaimable? yes lowmem_reserve[]: 0 0 0 0 DMA: 64kB 28kB 716kB 832kB 864kB 7128kB 5256kB 0512kB 01024kB 02048kB 04096kB = 3096kB Normal: 6394kB 2978kB 916kB 032kB 064kB 0128kB 0256kB 0512kB 01024kB 02048kB 04096kB = 50 76kB HighMem: 64kB 18kB 016kB 332kB 064kB 0128kB 0256kB 0512kB 01024kB 02048kB 0*4096kB = 128kB 56664 total pagecache pages 55697 pages in swap cache Swap cache stats: add 17100319, delete 17044622, find 7567477/9043262 Free swap = 0kB Total swap = 524284kB 198640 pages RAM 13826 pages HighMem 6639 pages reserved 14545 pages shared 188067 pages non-shared Out of memory: Kill process 3448 (httpd) score 41 or sacrifice child Killed process 3448 (httpd) total-vm:74716kB, anon-rss:26132kB, file-rss:1120kB
Processes running
[root@li21-298 ~]# ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 2208 492 ? Ss 19:34 0:00 init [3]
root 2 0.0 0.0 0 0 ? S 19:34 0:00 [kthreadd]
root 3 0.0 0.0 0 0 ? S 19:34 0:00 [ksoftirqd/0]
root 4 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/0:0]
root 5 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/u:0]
root 6 0.0 0.0 0 0 ? S 19:34 0:00 [migration/0]
root 7 0.0 0.0 0 0 ? S 19:34 0:00 [migration/1]
root 9 0.0 0.0 0 0 ? S 19:34 0:00 [ksoftirqd/1]
root 10 0.0 0.0 0 0 ? S 19:34 0:00 [migration/2]
root 12 0.0 0.0 0 0 ? S 19:34 0:00 [ksoftirqd/2]
root 13 0.0 0.0 0 0 ? S 19:34 0:00 [migration/3]
root 15 0.0 0.0 0 0 ? S 19:34 0:00 [ksoftirqd/3]
root 16 0.0 0.0 0 0 ? S< 19:34 0:00 [cpuset]
root 17 0.0 0.0 0 0 ? S< 19:34 0:00 [khelper]
root 18 0.0 0.0 0 0 ? S 19:34 0:00 [kdevtmpfs]
root 19 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/u:1]
root 21 0.0 0.0 0 0 ? S 19:34 0:00 [xenwatch]
root 22 0.0 0.0 0 0 ? S 19:34 0:00 [xenbus]
root 162 0.0 0.0 0 0 ? S 19:34 0:00 [sync_supers]
root 164 0.0 0.0 0 0 ? S 19:34 0:00 [bdi-default]
root 166 0.0 0.0 0 0 ? S< 19:34 0:00 [kblockd]
root 176 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/3:1]
root 178 0.0 0.0 0 0 ? S< 19:34 0:00 [md]
root 262 0.0 0.0 0 0 ? S< 19:34 0:00 [rpciod]
root 263 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/2:1]
root 275 0.0 0.0 0 0 ? S 19:34 0:04 [kswapd0]
root 276 0.0 0.0 0 0 ? SN 19:34 0:00 [ksmd]
root 277 0.0 0.0 0 0 ? S 19:34 0:00 [fsnotify_mark]
root 281 0.0 0.0 0 0 ? S 19:34 0:00 [ecryptfs-kthr]
root 283 0.0 0.0 0 0 ? S< 19:34 0:00 [nfsiod]
root 284 0.0 0.0 0 0 ? S< 19:34 0:00 [cifsiod]
root 287 0.0 0.0 0 0 ? S 19:34 0:00 [jfsIO]
root 288 0.0 0.0 0 0 ? S 19:34 0:00 [jfsCommit]
root 289 0.0 0.0 0 0 ? S 19:34 0:00 [jfsCommit]
root 290 0.0 0.0 0 0 ? S 19:34 0:00 [jfsCommit]
root 291 0.0 0.0 0 0 ? S 19:34 0:00 [jfsCommit]
root 292 0.0 0.0 0 0 ? S 19:34 0:00 [jfsSync]
root 293 0.0 0.0 0 0 ? S< 19:34 0:00 [xfsalloc]
root 294 0.0 0.0 0 0 ? S< 19:34 0:00 [xfs_mru_cache]
root 295 0.0 0.0 0 0 ? S< 19:34 0:00 [xfslogd]
root 296 0.0 0.0 0 0 ? S< 19:34 0:00 [glock_workque]
root 297 0.0 0.0 0 0 ? S< 19:34 0:00 [delete_workqu]
root 298 0.0 0.0 0 0 ? S< 19:34 0:00 [gfs_recovery]
root 299 0.0 0.0 0 0 ? S< 19:34 0:00 [crypto]
root 862 0.0 0.0 0 0 ? S 19:34 0:00 [khvcd]
root 976 0.0 0.0 0 0 ? S< 19:34 0:00 [kpsmoused]
root 1016 0.0 0.0 0 0 ? S< 19:34 0:00 [deferwq]
root 1019 0.0 0.0 0 0 ? S 19:34 0:00 [kjournald]
root 1023 0.0 0.0 0 0 ? S 19:34 0:00 [kworker/1:1]
root 1044 0.0 0.0 0 0 ? S 19:34 0:00 [kauditd]
root 1077 0.0 0.0 2424 356 ? S<s 19:34 0:00 /sbin/udevd -d
root 2692 0.0 0.0 2452 40 ? Ss 19:34 0:00 /sbin/dhclient
root 2759 0.0 0.0 10624 420 ? S<sl 19:34 0:00 auditd
root 2761 0.0 0.0 11184 444 ? S<sl 19:34 0:00 /sbin/audispd
root 2781 0.0 0.0 1964 532 ? Ss 19:34 0:00 syslogd -m 0
root 2784 0.0 0.0 1808 288 ? Ss 19:34 0:00 klogd -x
named 2825 0.0 0.1 58936 1032 ? Ssl 19:34 0:00 /usr/sbin/named
dbus 2847 0.0 0.0 2896 504 ? Ss 19:34 0:00 dbus-daemon --s
root 2884 0.0 0.0 23272 524 ? Ssl 19:34 0:00 automount
root 2903 0.0 0.0 7256 632 ? Ss 19:34 0:00 /usr/sbin/sshd
ntp 2917 0.0 0.5 4548 4544 ? SLs 19:34 0:00 ntpd -u ntp:ntp
root 2928 0.0 0.0 5344 160 ? Ss 19:34 0:00 /usr/sbin/vsftp
root 2964 0.0 0.0 4676 572 ? S 19:34 0:00 /bin/sh /usr/bi
root 3018 0.0 0.0 0 0 ? S 19:34 0:00 [flush-202:0]
mysql 3057 7.9 1.7 126808 13296 ? Sl 19:34 14:23 /usr/libexec/my
root 3089 0.0 0.0 9372 696 ? Ss 19:34 0:00 sendmail: accep
smmsp 3097 0.0 0.0 8284 336 ? Ss 19:34 0:00 sendmail: Queue
root 3106 0.0 0.0 2044 152 ? Ss 19:34 0:00 gpm -m /dev/inp
root 3115 0.0 0.1 27820 1320 ? Ss 19:34 0:00 /usr/sbin/httpd
root 3123 0.0 0.0 5380 552 ? Ss 19:34 0:00 crond
xfs 3141 0.0 0.0 3308 436 ? Ss 19:34 0:00 xfs -droppriv -
apache 3235 0.0 4.6 56924 35484 ? S 19:34 0:03 /usr/sbin/httpd
apache 3239 0.0 5.7 72740 44192 ? S 19:34 0:04 /usr/sbin/httpd
apache 3240 0.0 4.4 56636 34068 ? S 19:34 0:02 /usr/sbin/httpd
apache 3241 0.0 4.1 52836 31660 ? S 19:34 0:01 /usr/sbin/httpd
apache 3242 0.0 3.9 52800 30372 ? S 19:34 0:01 /usr/sbin/httpd
apache 3243 0.0 4.0 52788 31428 ? S 19:34 0:02 /usr/sbin/httpd
apache 3244 0.0 4.4 56924 34556 ? S 19:34 0:02 /usr/sbin/httpd
apache 3245 0.0 4.5 57196 34828 ? S 19:34 0:03 /usr/sbin/httpd
root 3264 0.0 0.0 2408 180 ? Ss 19:34 0:00 /usr/sbin/atd
root 3279 0.0 0.2 26680 2192 ? SN 19:34 0:00 /usr/bin/python
root 3281 0.0 0.0 2704 536 ? SN 19:34 0:00 /usr/libexec/ga
root 3282 0.0 0.2 19420 1660 ? Ss 19:34 0:00 /usr/bin/perl /
apache 3491 0.0 3.3 52792 26060 ? S 19:35 0:01 /usr/sbin/httpd
apache 3492 0.0 4.8 59656 37352 ? S 19:35 0:02 /usr/sbin/httpd
apache 3493 0.0 4.5 56956 34564 ? S 19:35 0:01 /usr/sbin/httpd
apache 3494 0.0 4.0 52788 31128 ? S 19:35 0:03 /usr/sbin/httpd
root 5343 0.0 0.0 3028 624 ? Ss 19:49 0:00 login -- root
root 5796 0.0 0.0 4808 604 hvc0 Ss 19:53 0:00 -bash
root 6054 0.0 0.0 0 0 ? S 19:55 0:00 [kworker/0:2]
root 6583 0.0 0.0 4320 352 hvc0 S+ 20:00 0:00 less
root 21913 0.0 0.0 0 0 ? S 21:53 0:00 [kworker/2:0]
root 22407 0.0 0.0 0 0 ? S 21:57 0:00 [kworker/3:0]
root 23117 0.0 0.0 0 0 ? S 22:02 0:00 [kworker/1:0]
root 24625 0.0 0.3 10264 2656 ? Ss 22:13 0:00 sshd: root@nott
root 24628 0.0 0.1 6692 1536 ? Ss 22:13 0:00 /usr/libexec/op
root 26703 0.0 0.3 10108 2932 ? Rs 22:28 0:00 sshd: root@pts/
root 26812 0.0 0.1 4812 1452 pts/0 Ss 22:29 0:00 -bash
root 27493 0.0 0.0 0 0 ? S 22:34 0:00 [kworker/1:2]
root 27494 0.0 0.1 4400 932 pts/0 R+ 22:34 0:00 ps aux
Free usage stats
[root@li21-298 ~]# free -m
total used free shared buffers cached
Mem: 750 497 252 0 6 77
-/+ buffers/cache: 413 336
Swap: 511 87 424
[root@li21-298 ~]# free
total used free shared buffers cached
Mem: 768004 490708 277296 0 8680 79892
-/+ buffers/cache: 402136 365868
Swap: 524284 73136 451148
List of running processes sorted by memory use
ps -eo pmem,pcpu,rss,vsize,args | sort -k 1 -r | less
%MEM %CPU RSS VSZ COMMAND
4.9 0.0 38240 59656 /usr/sbin/httpd
4.7 0.0 36324 72740 /usr/sbin/httpd
4.6 0.0 35724 56940 /usr/sbin/httpd
4.6 0.0 35512 56924 /usr/sbin/httpd
4.2 0.0 32676 56924 /usr/sbin/httpd
4.2 0.0 32312 56380 /usr/sbin/httpd
3.8 0.0 29604 52800 /usr/sbin/httpd
3.7 0.0 29024 52792 /usr/sbin/httpd
3.7 0.0 28992 52788 /usr/sbin/httpd
3.7 0.0 28664 52788 /usr/sbin/httpd
1.8 7.8 13928 127624 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
0.9 0.0 7260 52836 /usr/sbin/httpd
0.5 0.0 4544 4548 ntpd -u ntp:ntp -p /var/run/ntpd.pid -g
0.3 0.0 2940 10108 sshd: root@pts/0
0.3 0.0 2680 26680 /usr/bin/python -tt /usr/sbin/yum-updatesd
0.2 0.0 2208 53236 /usr/sbin/httpd
0.2 0.0 1660 19420 /usr/bin/perl /usr/libexec/webmin/miniserv.pl /etc/webmin/miniserv.conf
0.1 0.0 1460 4812 -bash 0.1 0.0 1320 27820 /usr/sbin/httpd :
Type of MPM in use by Apache
[root@li21-298 ~]# httpd -V | grep 'MPM'
Server MPM: Prefork
-D APACHE_MPM_DIR="server/mpm/prefork"
Current settings in my httpd.conf file (/etc/httpd/httpd.conf)
StartServers 8
MinSpareServers 5
MaxSpareServers 20
ServerLimit 256
MaxClients 256
MaxRequestsPerChild 4000
Current settings in mysql (located /etc/my.cnf)
[mysqld]
max_allowed_packet=50M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql