High CPU usage with MPM Worker/Event

Hi.

Working with Apache I noticed one strange thing such as high consumption
of CPU.

It looks like this.
server status:
Parent Server Generation: 2
Server uptime: 27 minutes 54 seconds
Total accesses: 137589 - Total Traffic: 6.1 GB
CPU Usage: u80.91 s52.19 cu0 cs0 - 7.95% CPU load
82.2 requests/sec - 3.7 MB/second - 46.2 kB/request
62 requests currently being processed, 38 idle workers

Especially remarkable is that Top gives - 9999%
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11978 www 20 0 458m 111m 2000 S 9999 0.7 0:01.66
/opt/apache/2.2.9/sbin/httpd -k start
18151 www 20 0 453m 106m 1996 S 4 0.7 0:00.30
/opt/apache/2.2.9/sbin/httpd -k start
18911 www 20 0 333m 100m 1984 S 3 0.6 0:00.09
/opt/apache/2.2.9/sbin/httpd -k start
18942 www 20 0 421m 101m 1996 S 2 0.6 0:00.07
/opt/apache/2.2.9/sbin/httpd -k start

Accounting also shows high consumption of CPU.

I don't know how it really should be, but I think it's not quite normal.
Can it be peculiarity or feature of my configuration? Well I really need
some advice from those who use worker/event. Thanks in advance.

Configuration of my box:
2 x Quad-core CPUs Intel Xeon E5345 linux-2.6.25, gcc-4.1.2, libc-2.6.1

Apache-2.2.9 make options:
CFLAGS="-O3 -march=nocona -pipe -fPIC -fomit-frame-pointer -ftracer
-mfpmath=sse"

mpm config:
<IfModule mpm_event_module>
ServerLimit 48
StartServers 4
MaxClients 1200
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 0
</IfModule>

Example of my virtualhost:
<VirtualHost *>
<IfModule fcgid_module>
FCGIWrapper /path_to_phpwrapper
</IfModule>
CustomLog path_to_log combined
ErrorLog path_to_log
DocumentRoot /path_to_docroot
SetEnv PHPRC /path_to_php.ini
<IfModule php5_module>
php_admin_value *** ***
</IfModule>
ServerName example.com
ServerAlias www.example.com
ServerAlias www1.example.com
AddHandler server-parsed .htm
AddHandler server-parsed .html
AddHandler server-parsed .shtm
AddHandler server-parsed .shtml
RewriteEngine On
RewriteCond *** ***
# some rules for backend
RewriteRule *** *** [NC,L,P]
SuexecUserGroup user group
</VirtualHost>

Total number of virtual hosts is about 2000.

--
BRGDS. Alexey Vlasov.

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Hi.

I set MaxRequestPerChild = 400 (400 is average quantity of ESTABLISHED
connections), but it was only worse.

On Thu, Nov 06, 2008 at 12:01:00PM +0530, Arnab Ganguly wrote:
> Hi,
> Can you try with Non-zero MaxRequestPerChild value.Keep a value which is
> equal to number of request are particular process you want to handle.Once it
> is done the process will be killed and a new process is going to be
> started.I guess your CPU usage should come down.
> Thanks
> -A
>
> On Thu, Nov 6, 2008 at 2:49 AM, Alexey Vlasov <renton@renton.name> wrote:
>
> > Hi.
> >
> > Working with Apache I noticed one strange thing such as high consumption
> > of CPU.
> >
> > It looks like this.
> > server status:
> > Parent Server Generation: 2
> > Server uptime: 27 minutes 54 seconds
> > Total accesses: 137589 - Total Traffic: 6.1 GB
> > CPU Usage: u80.91 s52.19 cu0 cs0 - 7.95% CPU load
> > 82.2 requests/sec - 3.7 MB/second - 46.2 kB/request
> > 62 requests currently being processed, 38 idle workers
> >
> > Especially remarkable is that Top gives - 9999%
> > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> > 11978 www 20 0 458m 111m 2000 S 9999 0.7 0:01.66
> > /opt/apache/2.2.9/sbin/httpd -k start
> > 18151 www 20 0 453m 106m 1996 S 4 0.7 0:00.30
> > /opt/apache/2.2.9/sbin/httpd -k start
> > 18911 www 20 0 333m 100m 1984 S 3 0.6 0:00.09
> > /opt/apache/2.2.9/sbin/httpd -k start
> > 18942 www 20 0 421m 101m 1996 S 2 0.6 0:00.07
> > /opt/apache/2.2.9/sbin/httpd -k start
> >
> > Accounting also shows high consumption of CPU.
> >
> > I don't know how it really should be, but I think it's not quite normal.
> > Can it be peculiarity or feature of my configuration? Well I really need
> > some advice from those who use worker/event. Thanks in advance.
> >
> > Configuration of my box:
> > 2 x Quad-core CPUs Intel Xeon E5345 linux-2.6.25, gcc-4.1.2, libc-2.6.1
> >
> > Apache-2.2.9 make options:
> > CFLAGS="-O3 -march=nocona -pipe -fPIC -fomit-frame-pointer -ftracer
> > -mfpmath=sse"
> >
> > mpm config:
> > <IfModule mpm_event_module>
> > ServerLimit 48
> > StartServers 4
> > MaxClients 1200
> > MinSpareThreads 25
> > MaxSpareThreads 75
> > ThreadsPerChild 25
> > MaxRequestsPerChild 0
> > </IfModule>
> >
> > Example of my virtualhost:
> > <VirtualHost *>
> > <IfModule fcgid_module>
> > FCGIWrapper /path_to_phpwrapper
> > </IfModule>
> > CustomLog path_to_log combined
> > ErrorLog path_to_log
> > DocumentRoot /path_to_docroot
> > SetEnv PHPRC /path_to_php.ini
> > <IfModule php5_module>
> > php_admin_value *** ***
> > </IfModule>
> > ServerName example.com
> > ServerAlias www.example.com
> > ServerAlias www1.example.com
> > AddHandler server-parsed .htm
> > AddHandler server-parsed .html
> > AddHandler server-parsed .shtm
> > AddHandler server-parsed .shtml
> > RewriteEngine On
> > RewriteCond *** ***
> > # some rules for backend
> > RewriteRule *** *** [NC,L,P]
> > SuexecUserGroup user group
> > </VirtualHost>
> >
> > Total number of virtual hosts is about 2000.
> >
> > --
> > BRGDS. Alexey Vlasov.
> >
> > ---------------------------------------------------------------------
> > The official User-To-User support forum of the Apache HTTP Server Project.
> > See <URL:http://httpd.apache.org/userslist.html> for more info.
> > To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> > " from the digest: users-digest-unsubscribe@httpd.apache.org
> > For additional commands, e-mail: users-help@httpd.apache.org
> >
> >

--
BRGDS. Alexey Vlasov.

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Frankly speaking I don't know how many processes should be and how many
I need. I want to learn - why is CPU worker usage so high?

Constantly ~300-500 ESTAB
connections. My server-status you have seen. The number of processes is
~20-25.

On other server I have tried to use the following settings:
ServerLimit 5
ThreadLimit 125
StartServers 4
MaxClients 500
MinSpareThreads 25
MaxSpareThreads 125
ThreadsPerChild 100
MaxRequestsPerChild 0
The number of processes: ~10-15.
But the situation with CPU is the same.

On Mon, Nov 10, 2008 at 01:01:49PM +0530, Arnab Ganguly wrote:
> Hi ,
> Can you please tell me about your requirements like for example how many
> processes do you want to create for handling the request, it seems to me the
> number of processes are very high, you can try out increasing the number of
> threads per process that way you can reduce the number of processes, also
> introduce ThreadLimit param in order to increase the ThreadsPerChild.Let me
> know if I can help you.
> Thanks
> -A
>
> On Sun, Nov 9, 2008 at 10:31 PM, Alexey Vlasov <renton@renton.name> wrote:
>
> > Hi.
> >
> > I set MaxRequestPerChild = 400 (400 is average quantity of ESTABLISHED
> > connections), but it was only worse.
> >
> > On Thu, Nov 06, 2008 at 12:01:00PM +0530, Arnab Ganguly wrote:
> > > Hi,
> > > Can you try with Non-zero MaxRequestPerChild value.Keep a value which is
> > > equal to number of request are particular process you want to handle.Once
> > it
> > > is done the process will be killed and a new process is going to be
> > > started.I guess your CPU usage should come down.
> > > Thanks
> > > -A
> > >
> > > On Thu, Nov 6, 2008 at 2:49 AM, Alexey Vlasov <renton@renton.name>
> > wrote:
> > >
> > > > Hi.
> > > >
> > > > Working with Apache I noticed one strange thing such as high
> > consumption
> > > > of CPU.
> > > >
> > > > It looks like this.
> > > > server status:
> > > > Parent Server Generation: 2
> > > > Server uptime: 27 minutes 54 seconds
> > > > Total accesses: 137589 - Total Traffic: 6.1 GB
> > > > CPU Usage: u80.91 s52.19 cu0 cs0 - 7.95% CPU load
> > > > 82.2 requests/sec - 3.7 MB/second - 46.2 kB/request
> > > > 62 requests currently being processed, 38 idle workers
> > > >
> > > > Especially remarkable is that Top gives - 9999%
> > > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> > > > 11978 www 20 0 458m 111m 2000 S 9999 0.7 0:01.66
> > > > /opt/apache/2.2.9/sbin/httpd -k start
> > > > 18151 www 20 0 453m 106m 1996 S 4 0.7 0:00.30
> > > > /opt/apache/2.2.9/sbin/httpd -k start
> > > > 18911 www 20 0 333m 100m 1984 S 3 0.6 0:00.09
> > > > /opt/apache/2.2.9/sbin/httpd -k start
> > > > 18942 www 20 0 421m 101m 1996 S 2 0.6 0:00.07
> > > > /opt/apache/2.2.9/sbin/httpd -k start
> > > >
> > > > Accounting also shows high consumption of CPU.
> > > >
> > > > I don't know how it really should be, but I think it's not quite
> > normal.
> > > > Can it be peculiarity or feature of my configuration? Well I really
> > need
> > > > some advice from those who use worker/event. Thanks in advance.
> > > >
> > > > Configuration of my box:
> > > > 2 x Quad-core CPUs Intel Xeon E5345 linux-2.6.25, gcc-4.1.2, libc-2.6.1
> > > >
> > > > Apache-2.2.9 make options:
> > > > CFLAGS="-O3 -march=nocona -pipe -fPIC -fomit-frame-pointer -ftracer
> > > > -mfpmath=sse"
> > > >
> > > > mpm config:
> > > > <IfModule mpm_event_module>
> > > > ServerLimit 48
> > > > StartServers 4
> > > > MaxClients 1200
> > > > MinSpareThreads 25
> > > > MaxSpareThreads 75
> > > > ThreadsPerChild 25
> > > > MaxRequestsPerChild 0
> > > > </IfModule>
> > > >
> > > > Example of my virtualhost:
> > > > <VirtualHost *>
> > > > <IfModule fcgid_module>
> > > > FCGIWrapper /path_to_phpwrapper
> > > > </IfModule>
> > > > CustomLog path_to_log combined
> > > > ErrorLog path_to_log
> > > > DocumentRoot /path_to_docroot
> > > > SetEnv PHPRC /path_to_php.ini
> > > > <IfModule php5_module>
> > > > php_admin_value *** ***
> > > > </IfModule>
> > > > ServerName example.com
> > > > ServerAlias www.example.com
> > > > ServerAlias www1.example.com
> > > > AddHandler server-parsed .htm
> > > > AddHandler server-parsed .html
> > > > AddHandler server-parsed .shtm
> > > > AddHandler server-parsed .shtml
> > > > RewriteEngine On
> > > > RewriteCond *** ***
> > > > # some rules for backend
> > > > RewriteRule *** *** [NC,L,P]
> > > > SuexecUserGroup user group
> > > > </VirtualHost>
> > > >
> > > > Total number of virtual hosts is about 2000.
> > > >
> > > > --
> > > > BRGDS. Alexey Vlasov.
> > > >
> > > > ---------------------------------------------------------------------
> > > > The official User-To-User support forum of the Apache HTTP Server
> > Project.
> > > > See <URL:http://httpd.apache.org/userslist.html> for more info.
> > > > To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> > > > " from the digest: users-digest-unsubscribe@httpd.apache.org
> > > > For additional commands, e-mail: users-help@httpd.apache.org
> > > >
> > > >
> >
> > --
> > BRGDS. Alexey Vlasov.
> >

--
BRGDS. Alexey Vlasov.

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