Apache httpd Problem

Question

I am getting intermittent issues with my site. Pages often hang with huge loading times and sometimes fail to load.

The httpd error logs contain the following:

[Wed Feb 23 06:54:17 2011] [debug] proxy_util.c(1854): proxy: grabbed scoreboard slot 0 in child 5871 for worker proxy:reverse
[Wed Feb 23 06:54:17 2011] [debug] proxy_util.c(1967): proxy: initialized single connection worker 0 in child 5871 for (*)
[Wed Feb 23 06:54:24 2011] [debug] proxy_util.c(1854): proxy: grabbed scoreboard slot 0 in child 5872 for worker proxy:reverse
[Wed Feb 23 06:54:24 2011] [debug] proxy_util.c(1873): proxy: worker proxy:reverse already initialized
[Wed Feb 23 06:54:24 2011] [debug] proxy_util.c(1967): proxy: initialized single connection worker 0 in child 5872 for (*)
[Wed Feb 23 06:59:15 2011] [debug] proxy_util.c(1854): proxy: grabbed scoreboard slot 0 in child 5954 for worker proxy:reverse
[Wed Feb 23 06:59:15 2011] [debug] proxy_util.c(1873): proxy: worker proxy:reverse already initialized

The server is currently running with 800mb free memory, so it is not caused by lack of RAM.

Any suggestions would be greatly appreciated.

Many thanks,

Chris.

EDIT

The current number of httpd procceses is 11. This does increase as the error persists and can rise up to 25+.

I am running Apache/2.2.3 (CentOS).

Solution

Depending on your Apache2 worker module, you can try finding something like

StartServers           2
MaxClients            50
MinSpareThreads       25
MaxSpareThreads       25
ThreadsPerChild       25
MaxRequestsPerChild  500

from your apache configuration file (may be for example /etc/apache2/apache2.conf or httpd.conf).

If you raise MaxClients, then you can serve larger amount of clients.

You should monitor your server load before making too dramatic changes. Good tools for this are for example top, iotop (for IO load) and munin for drawing nice system load graphs.

Comments

[Admin]

To get any meaningful answers, you should add little bit more information about your setup: what proxy, what version of apache, what's running behind the proxy?

[Admin]

@Olli. Thank you for your response. I am running Apache/2.2.3 (CentOS). I was not aware I am usuing a proxy. I hope this helps. Thanks, Chris.

[Kit]

Hi Olli, thank you for your answer. I have tried the above suggestion and restarted httpd but the problem still remains and the same errors appear in the error log. Any other suggestions?