Unneeded Apache 2 Modules

I am running Apache 2.2.16 on Debian Squeeze with ISPConfig 3.0.3 and am looking to reduce my apache2 process memory footpint. Currently, running 'ps -ylC apache2 --sort:rss' gives me:

Code:

S    33 13100 24996  0  80   0 10452 65841 -      ?        00:00:00 apache2
S    33 13089 24996  0  80   0 10724 65963 -      ?        00:00:00 apache2
S    33 13088 24996  0  80   0 10728 65963 -      ?        00:00:00 apache2
S    33 13087 24996  0  80   0 10740 65963 -      ?        00:00:00 apache2
S    33 13090 24996  0  80   0 10824 65965 -      ?        00:00:00 apache2
S    33 13096 24996  0  80   0 12212 65920 -      ?        00:00:00 apache2
S    33 13065 24996  0  80   0 14848 66758 -      ?        00:00:00 apache2
S     0 24996     1  0  80   0 17704 65808 -      ?        00:00:01 apache2
S    33 13061 24996  0  80   0 21816 68390 -      ?        00:00:00 apache2
S    33 13085 24996  1  80   0 29464 69924 -      ?        00:00:00 apache2
S    33 12776 24996  0  80   0 30200 70431 -      ?        00:00:00 apache2
S    33 12775 24996  0  80   0 30544 69999 -      ?        00:00:00 apache2
S    33 12271 24996  0  80   0 39424 72353 -      ?        00:00:00 apache2
S    33 13084 24996  1  80   0 43220 73327 -      ?        00:00:00 apache2
S    33 13063 24996  1  80   0 43400 73343 -      ?        00:00:01 apache2
S    33 13095 24996  2  80   0 43936 73552 -      ?        00:00:00 apache2
S    33 12774 24996  0  80   0 44200 73539 -      ?        00:00:00 apache2
S    33 13101 24996  3  80   0 45212 73882 -      ?        00:00:00 apache2
S    33 13059 24996  1  80   0 45712 74024 -      ?        00:00:00 apache2
S    33 13099 24996  3  80   0 45872 74077 -      ?        00:00:00 apache2
S    33 13094 24996  4  80   0 46148 74140 -      ?        00:00:00 apache2
S    33 12781 24996  1  80   0 50676 75153 -      ?        00:00:01 apache2

My enabled modules are currently:

Code:

actions.conf          authz_user.load  include.load      proxy.load
actions.load          autoindex.conf   mime.conf         reqtimeout.conf
alias.conf            autoindex.load   mime.load         reqtimeout.load
alias.load            cgi.load         negotiation.conf  rewrite.load
auth_basic.load       deflate.conf     negotiation.load  setenvif.conf
authn_file.load       deflate.load     php5.conf         setenvif.load
authz_default.load    dir.conf         php5.load         status.conf
authz_groupfile.load  dir.load         proxy.conf        status.load
authz_host.load       env.load         proxy_http.load   suexec.load

Apache2.conf has Timeout 30, KeepAliveTimeout 15, MaxKeepAliveRequests 100 and prefork with:

Code:

    StartServers          5
    MinSpareServers       5
    MaxSpareServers      10
    MaxClients          75
    MaxRequestsPerChild 1000

Why are my apache processes running at 50Mb each?

Regards,

Lewis

 

Have you tried this guide? http://www.howtoforge.com/configuring_apache_for_maximum_performance

Also, do you use some sort of PHP opcode cacher, e.g. eAccelerator, Xcache, or APC?

 

Hey falko,

Thank you for getting back to me. I don't use any sort of PHP opcode cacher, and have seen the article you mentioned.

I already have HostnameLookups Off, and configured MaxClients and whatnot, as specified earlier. Out of the modules that I currently have enabled, are there any known 'offenders' who use a large amount of RAM? What's the primary reason that my apache2 processes would be using 50Mb of RAM so quickly after starting?

Regards,

Lewis

 

I'm using

Code:

Timeout 300
MaxKeepAliveRequests 1000000
KeepAliveTimeout 2
StartServers          5
MinSpareServers       5
MaxSpareServers      10
MaxRequestsPerChild   0

Can you try these?

 

By setting 'MaxRequestsPerChild' to 0, the apache documentation says: 'the process will never expire' - is that really what one wants?

Additionally, will any of those settings have any immediate effect on the memory footprint?

 

Your guide says that the memory should be 2-3Mb, or 15Mb if using PHP, but then you tell me that it is normal that I have 50Mb processes?

Also, I have already gotten rid of all the modules I believe I am not using. The rest I am unsure about. I am definitely using the proxy stuff, but is it a known memory hog?

 

http://www.howtoforge.com/configuring_apache_for_maximum_performance

"Child process size for serving static file is about 2-3M. For dynamic content such as PHP, it may be around 15M."

 

Thank you for clarifying. So, my 50Mb memory usage is normal, and I should ensure that 50Mb x MaxClients is less than the total amount of free system memory I have...