[admin]

Very interesting links admin, Thank you very much!

In example: If you have 20 Apache processes and each is being reported as 15MB, there is a very good possibility that what you really have is 20 10MB processes that are also sharing common libraries that are another 5MB.

So when we did:

Code:

ps -ylC httpd --sort:rss

the last value of RSS is the total value that Apache is using in this moment? Or only the memory to one process of apache? I think that is the total value of memory loaded by one process child of apache, not the total RAM used by apache, isn't it?

[How you discover the exactly or properly value for Max Clients?]

Hi everybody and congratulations by site, very helpfult. First of all, i don't know if this is the properly forum to my question. Is about a tutorial about "Tunning and performance Apache":

http://www.devside.net/articles/apache-performance-tuning I found your web through MySQL Performance Blog.

MaxClients ≈ (RAM - size_all_other_processes)/(size_apache_process)

Use 'ps -ylC httpd --sort:rss' to find process size. Divide number by 1024 to get megabytes. Also try 'top'.

Use 'free -m' for a general overview. The key figure to look at is the buffers/cache used value.

Use 'vmstat 2 5' to display the number of runnable, blocked, and waiting processes; and swap in and swap out.

Example:

    * System: VPS (Virtual Private Server), CentOS 4.4, with 128MB RAM
    * Apache: v2.0, mpm_prefork, mod_php, mod_rewrite, mod_ssl, and other modules
    * Other Services: MySQL, Bind, SendMail
    * Reported System Memory: 120MB
    * Reported httpd process size: 7-13MB
    * Assumed memory available to Apache: 90MB

Optimal settings:

    * StartServers 5
    * MinSpareServers 5
    * MaxSpareServers 10
    * ServerLimit 15
    * MaxClients 15
    * MaxRequestsPerChild 2000

I don't understand how author of tutorial find the exaclty number to MaxClients. We know the total amount of RAM, and the total amount used by APACHE.

APACHE = 7-13 MB (totally?)
RAM      =  128 MB
REST OF SO= ???

Max Clients = 15

How you discover the exactly or properly value for Max Clients? My first doubt is how to find the total amount in memory of all process that are not httpd childs, to make the correct formula.

Great tutorial! Thanks.