Apache : low load but too high memory usage

[Webou]

Hello,

I have a VPS on which sometimes PHP files cause "Internal Server Error".
I have apache 2.2 and php 5.2.4 , last version of cpanel.

In my error log I have these messages :

(12)Cannot allocate memory: couldn't create child process: /opt/suphp/sbin/suphp for /home/...

So, in ssh ps aux I can see that it's a multiplication of apache childs which causes a too high memory usage.

My question is :

Which parameter should I change to limit the number of child processes ?

The aim of this is that the users get in queue, instead of seeing the "Internal server error".

I searched for it, googled it, but could not find the answer.

Thanks in advance,

Michael

[AndyReed]

I have a VPS on which sometimes PHP files cause "Internal Server Error".
I have apache 2.2 and php 5.2.4 , last version of cpanel.

In my error log I have these messages :

(12)Cannot allocate memory: couldn't create child process: /opt/suphp/sbin/suphp for /home/...

View /usr/lib/php.ini file and post "Resource Limits" parameters here.

[Webou]

Hello and thanks for your help.

Here it is :

;;;;;;;;;;;;;;;;;;;
; Resource Limits ;
;;;;;;;;;;;;;;;;;;;

max_execution_time = 30     ; Maximum execution time of each script, in seconds
max_input_time = 60	; Maximum amount of time each script may spend parsing request data
memory_limit = 32M      ; Maximum amount of memory a script may consume (8MB)

May be the problem is that the VPS does not SWAP. Instead, it just denies the request when there is not enough available memory.

[Webou]

This shows that it's the number of apache childs wich is the problem :

USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  1628  596 ?        Ss   Nov09   0:00 init [3]
root     31765  0.0  0.0  1532  536 ?        Ss   Nov09   0:04 syslogd -m 0
named    31779  0.0  0.0 70868 5856 ?        Ssl  Nov09   0:12 /usr/sbin/named -
root     31821  0.0  0.0  1456  384 ?        S    Nov09   0:00 /usr/sbin/courier
root     31822  0.0  0.0  1804  608 ?        S    Nov09   0:00 /usr/libexec/cour
root     31849  0.0  0.0  1804  368 ?        S    Nov09   0:00 /usr/libexec/cour
root     31850  0.0  0.0  1804  368 ?        S    Nov09   0:00 /usr/libexec/cour
root     31853  0.0  0.0  1804  368 ?        S    Nov09   0:00 /usr/libexec/cour
root     31854  0.0  0.0  1804  368 ?        S    Nov09   0:00 /usr/libexec/cour
root     31855  0.0  0.0  1804  368 ?        S    Nov09   0:00 /usr/libexec/cour
root     32680  0.0  0.0  4016 1128 ?        Ss   Nov09   0:03 /usr/sbin/sshd
root     32692  0.0  0.0  2080  792 ?        Ss   Nov09   0:00 xinetd -stayalive
root     32712  0.0  0.0  2152 1120 ?        S    Nov09   0:00 /bin/sh /usr/bin/
mysql    32738  2.3  0.4 135016 34644 ?      Sl   Nov09  81:45 /usr/sbin/mysqld
root      1353  0.0  0.0  1460  388 ?        S    Nov09   0:00 /usr/sbin/courier
root      1354  0.0  0.0  1568  508 ?        S    Nov09   0:00 /usr/lib/courier-
root      1368  0.0  0.0  1460  388 ?        S    Nov09   0:00 /usr/sbin/courier
root      1369  0.0  0.0  1568  508 ?        S    Nov09   0:00 /usr/lib/courier-
root      1376  0.0  0.0  1460  388 ?        S    Nov09   0:00 /usr/sbin/courier
root      1377  0.0  0.0  1568  508 ?        S    Nov09   0:00 /usr/lib/courier-
root      1387  0.0  0.0  1460  388 ?        S    Nov09   0:00 /usr/sbin/courier
root      1388  0.0  0.0  1568  508 ?        S    Nov09   0:00 /usr/lib/courier-
root      1823  0.0  0.0  6088 1380 ?        Ss   Nov09   0:01 pure-ftpd (SERVER
root      1826  0.0  0.0  3576  916 ?        S    Nov09   0:00 /usr/sbin/pure-au
root      1885  0.0  0.0  3576  912 ?        S    Nov09   0:00 /usr/sbin/pure-au
root      3087  0.0  0.0  6536 4840 ?        S    Nov09   0:00 cpbandwd
root      3088  0.1  0.1 13696 11080 ?       SN   Nov09   3:49 cpanellogd - slee
mailman   3170  0.0  0.0 10288 5076 ?        Ss   Nov09   0:00 /usr/local/bin/py
mailman   3180  0.0  0.0 10112 6680 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3181  0.0  0.0 10080 6692 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3182  0.0  0.0 10052 6692 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3183  0.0  0.0 10112 6680 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3184  0.0  0.0 10060 6712 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3185  0.0  0.0 10596 7236 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3186  0.0  0.0 10112 6676 ?        S    Nov09   0:00 /usr/local/bin/py
mailman   3187  0.0  0.0 10112 6676 ?        S    Nov09   0:00 /usr/local/bin/py
root      3195  0.0  0.0  4052  804 ?        Ss   Nov09   0:00 /usr/sbin/saslaut
root      3229  0.0  0.0  1488  396 ?        Ss   Nov09   0:00 /usr/sbin/portsen
root      3404  0.0  0.0  6664 5044 ?        S    Nov09   0:10 /etc/authlib/auth
root      8140  0.0  0.0  6664 5044 ?        S    Nov09   0:10 /etc/authlib/auth
root     18148  0.0  0.0  6664 5044 ?        S    Nov09   0:08 /etc/authlib/auth
root     21946  0.0  0.0  6664 5044 ?        S    Nov09   0:09 /etc/authlib/auth
root     32579  0.0  0.0  6664 5044 ?        S    Nov09   0:10 /etc/authlib/auth
root     17883  0.0  0.0  2484  944 ?        Ss   Nov10   0:00 crond
root     27982  0.0  0.0  6716 5108 ?        S    Nov10   0:02 chkservd
mailnull  9285  0.0  0.0  7616 2052 ?        Ss   Nov10   0:03 /usr/sbin/exim -b
mailnull  9291  0.0  0.0  8532 2020 ?        Ss   Nov10   0:00 /usr/sbin/exim -t
root      9298  0.0  0.0  3528 1520 ?        S    Nov10   0:02 antirelayd
root     21691  0.0  0.3 26636 25056 ?       S    Nov10   0:51 /usr/bin/perl /us
root      3834  0.0  0.1 20804 10296 ?       S    01:59   0:04 cpsrvd - waiting
root      9616  0.0  0.2 43080 21432 ?       Ss   03:02   0:08 /usr/local/apache
root      5235  0.0  0.0  7056 2396 ?        Rs   11:21   0:00 sshd: root@ttyp0
root      5272  0.0  0.0  2288 1340 ttyp0    Ss   11:21   0:00 -bash
arthur70  3868  0.0  0.0  6108 1100 ?        S    12:43   0:00 pure-ftpd (IDLE)
timoline  1391  0.0  0.0  6200 1160 ?        S    13:05   0:00 pure-ftpd (IDLE)
nobody    7434  0.0  0.2 43336 21592 ?       S    13:10   0:00 /usr/local/apache
nobody    7463  0.1  0.2 43224 21296 ?       S    13:10   0:00 /usr/local/apache
nobody    9307  0.1  0.2 43220 21404 ?       S    13:11   0:00 /usr/local/apache
nobody   11618  0.0  0.2 43220 21428 ?       S    13:13   0:00 /usr/local/apache
nobody   11632  0.1  0.2 43224 21372 ?       S    13:13   0:00 /usr/local/apache
nobody   11962  0.0  0.2 43356 21444 ?       S    13:14   0:00 /usr/local/apache
nobody   12018  0.0  0.2 43232 21432 ?       S    13:14   0:00 /usr/local/apache
nobody   14126  0.1  0.2 43220 21296 ?       S    13:15   0:00 /usr/local/apache
nobody   14127  0.0  0.2 43224 21396 ?       S    13:15   0:00 /usr/local/apache
nobody   15523  0.0  0.2 43216 21412 ?       S    13:15   0:00 /usr/local/apache
nobody   16165  0.0  0.2 43216 21392 ?       S    13:16   0:00 /usr/local/apache
nobody   17537  2.3  0.3 53816 31928 ?       S    13:17   0:01 /usr/local/apache
nobody   17875  0.0  0.2 43216 21220 ?       S    13:17   0:00 /usr/local/apache
nobody   17884  0.0  0.2 43216 21396 ?       S    13:17   0:00 /usr/local/apache
nobody   17885  0.0  0.2 43224 21348 ?       S    13:17   0:00 /usr/local/apache
nidaime  17912 27.6  0.1 23024 9748 ?        S    13:17   0:15 /usr/bin/php
nobody   17995  0.0  0.2 43216 21320 ?       S    13:17   0:00 /usr/local/apache
nobody   18011  0.0  0.2 43216 21364 ?       S    13:18   0:00 /usr/local/apache
nobody   18066  0.0  0.2 43216 21380 ?       S    13:18   0:00 /usr/local/apache
zangdar  18167  0.0  0.0  6108 1056 ?        S    13:18   0:00 pure-ftpd (IDLE)
nobody   18276  0.0  0.2 43216 21260 ?       S    13:18   0:00 /usr/local/apache
nobody   18428  0.0  0.2 43212 21256 ?       S    13:18   0:00 /usr/local/apache
root     19667  0.0  0.0  2316  792 ttyp0    R+   13:18   0:00 ps aux

[AndyReed]

May be the problem is that the VPS does not SWAP. Instead, it just denies the request when there is not enough available memory.

What is the guaranteed/Burst System Memory assigned to your VPS?

[Webou]

It's 384Mo - 1 Go.

The thing is that I have a lot of accounts (~700), so the memory goes easily up to 1Go, and when it happens, I have the "Internal Server Error".

I'd like to avoid that...

I counted the number of apache childs when I overuse memory, and it was 32. So I'd like to limit this number to 30. How can I do that?

[AndyReed]

The thing is that I have a lot of accounts (~700), so the memory goes easily up to 1Go, and when it happens, I have the "Internal Server Error".

I'd like to avoid that...

With 700 client on a VPS, no surprise to hit the max of your RAM Memory very quick. Ask your host to increase your Memory to 2GB or more, if they have'em!

[Webou]

Yes sure, upgrading would be the easiest thing to do

But I'm looking for a solution with the present configuration. It should be possible to lower the number of apache childs, no?

[sehh]

i encountered the same problem, i believe its because i compiled apache with the "worker" MPM instead of prefork.

it seems the "worker" by default is set to use too much memory.