Error server reached MaxClients setting

[ManuelG2k]

Hello,
I have Ubuntu Server 12.04.3 LTS and Plesk 11.5.30 Update #18.
This is a Virtual Server with 2 vCPU (4,80 Ghz total), ram 4 Gb.
The server has 13 domains.
Average server utilization is this: CPU 10%, RAM 50%, active processes 110-115

Occasionally the sites are inaccessible and you can not connect to the server console.
At that moment, the active processes are 250, the CPU is at 100%.

I'm trying to understand the cause.

On /var/log/apache2/error.log I find this line (when the server is overloaded):

[Tue Oct 15 12:42:20 2013] [error] server reached MaxClients setting, consider raising the MaxClients setting


This could be the cause?
Can you help me ?


Tnx in advance
Manuel

 

[InderS]

Hello,

You are getting this issues because your one of the site is having the high traffic and due to that your CPU usages is 100% and you are getting this MaxClients exceeded issues on your server, I will suggest you monitor your server and try to disable your high traffic website OR try to optimized Apache on your server


Thank you

 

[ManuelG2k]

Hello,

You are getting this issues because your one of the site is having the high traffic and due to that your CPU usages is 100% and you are getting this MaxClients exceeded issues on your server, I will suggest you monitor your server and try to disable your high traffic website OR try to optimized Apache on your server


Thank you

Thanks InderS, obviously I can not disable the website.
How can I optimized Apache ?
You have any suggestions ?

 

[InderS]

Hello,

Yes, I will suggest you take backup of your Apache config file and try to add following setting.

<IfModule prefork.c>
StartServers 8
MinSpareServers 5
MaxSpareServers 30
ServerLimit 550
MaxClients 550
MaxRequestsPerChild 4000
</IfModule>

Also check : http://httpd.apache.org/docs/2.2/misc/perf-tuning.html

 

[ManuelG2k]

Tnx InderS.
The Apache config file on Ubuntu server with Plesk 11 I think is /etc/apache2/apache2.conf ?
In this file I not have "prefork.c", but "mpm_prefork_module", "mpm_worker_module" and "mpm_event_module".
I need to modify "mpm_prefork_module" section ?

Actually I have

<IfModule mpm_prefork_module>
    StartServers          5
    MinSpareServers       5
    MaxSpareServers      10
    MaxClients          150
    MaxRequestsPerChild   0
</IfModule>

Tnx
Manuel

 

[InderS]

Hello,

Yes, Please try to add these setting in mpm_prefork_module section and check your site.