High load apache

[Paras pradhan <pradhanparas@xxxxxxxxx>]

Hi,

Looking for recommendations. 

I need to serve 100-200+ concurrent users to provide php based webmail client (horde). I have setup memcached and php-fastcgid for this purpose. The server has four 2.2G AMD optereon cores with 8GB of memory. I am doing stress test using ab as: ab -t 36000 -c 100 https://url/h/imp/login.php. What I have noticed if the number of concurrent users are more than around 25, I get the sluggish performance and I can see linux load rising high to 25 to 30 and all the cpu cores are approximately 75% used.

This is what I have in config files:

mpm worker:

--

<IfModule worker.c>

StartServers         15

MaxClients         960

MinSpareThreads     75

MaxSpareThreads     150

ThreadsPerChild     64

MaxRequestsPerChild  5000

--

memcached: 4GB

---

fcgid:

<IfModule !mod_fastcgi.c>

  AddHandler fcgid-script .fcgi

  MaxRequestsPerProcess 10000

  MaxProcessCount       100

  IPCCommTimeout        240

  IdleTimeout           240

  ProcessLifeTime 300

  BusyTimeout 300

  DefaultMaxClassProcessCount 100

  DefaultMinClassProcessCount 50

</IfModule>

---

php-fcgid:

# Number of PHP childs that will be launched. Leave undefined to let PHP decide.

#    DefaultInitEnv PHP_FCGI_CHILDREN 4

    

# Maximum requests before a process is stopped and a new one is launched

    DefaultInitEnv PHP_FCGI_MAX_REQUESTS 10000

----

OS: RHEL 5.5

Apache: 2.2.3

PHP: 5.1

Mysql: 5.0

Will appreciate for any inputs.

Thanks!

Paras.