My VPS plan gives me 1GB of RAM burstable to 2GB.
Of course I cannot use 2 GB, nor 1 GB, everyday, so I'm planning to optimize the performance of my webserver.
The average of hits-per-hour is about 8'000-10'000. This means about 2 connections-per-second.
Max hits-per-hour reached until now is about 60'000. That means about 16 connections-per-second.
Unluckily my current apache configuration uses too much memory (when there are not connected clients - usually during the night - it uses about 1GB) so I've tried to customize the apache installation to fit to my needs.
I'm using Ubuntu, kernel 2.6.18, with apache2-mpm-worker, since I've read it requires less memory, and fcgid ( + PHP). This is my /etc/apache2/apache2.conf:
Timeout 45
KeepAlive on
MaxKeepAliveRequests 100
KeepAliveTimeout 10
<IfModule mpm_worker_module>
StartServer 2
MinSpareThreads 25
MaxSpareThreads 75
MaxClients 100
MaxRequestsPerChild 0
</IfModule>
This is the output of ps aux:
www-data 9547 0.0 0.3 423828 7268 ? Sl 20:09 0:00 /usr/sbin/apache2 -k start
root 17714 0.0 0.1 76496 3712 ? Ss Feb05 0:00 /usr/sbin/apache2 -k start
www-data 17716 0.0 0.0 75560 2048 ? S Feb05 0:00 /usr/sbin/apache2 -k start
www-data 17746 0.0 0.1 76228 2384 ? S Feb05 0:00 /usr/sbin/apache2 -k start
www-data 20126 0.0 0.3 424852 7588 ? Sl 19:24 0:02 /usr/sbin/apache2 -k start
www-data 24260 0.0 0.3 424852 7580 ? Sl 19:42 0:01 /usr/sbin/apache2 -k start
while this is ps aux for php5:
www-data 7461 2.9 2.2 142172 47048 ? S 19:39 1:39 /usr/lib/cgi-bin/php5
www-data 23845 1.3 1.7 135744 35948 ? S 20:17 0:15 /usr/lib/cgi-bin/php5
www-data 23900 2.0 1.7 136692 36760 ? S 20:17 0:22 /usr/lib/cgi-bin/php5
www-data 27907 2.0 2.0 142272 43432 ? S 20:00 0:43 /usr/lib/cgi-bin/php5
www-data 27909 2.5 1.9 138092 40036 ? S 20:00 0:53 /usr/lib/cgi-bin/php5
www-data 27993 2.4 2.2 142336 47192 ? S 20:01 0:50 /usr/lib/cgi-bin/php5
www-data 27999 1.8 1.4 135932 31100 ? S 20:01 0:38 /usr/lib/cgi-bin/php5
www-data 28230 2.6 1.9 143436 39956 ? S 20:01 0:54 /usr/lib/cgi-bin/php5
www-data 30708 3.1 2.2 142508 46528 ? S 19:44 1:38 /usr/lib/cgi-bin/php5
As you can see it use a lot of memory.
How can I reduce it to fit to just 1GB of RAM?
PS: I also think about the switch to nginx, if Apache can't fit to my needs...
