We had been facing the FD_SETSIZE error for the last few days wherein perl scripts used to turn blank after about 1 hour and apache used to hangup every 2-3 hours. The error showed the above error.

We fixed this error in the following way. Hope this works for you also.

1. do easyapache using the 6th option.
2. raise HARD_SERVER_LIMIT and FD_SETSIZE
3. save and compile with other required options.

Some entries in httpd.conf need to be checked for.
4. Edit httpd.conf check for the following parameters.

MinSpareServers 5
MaxSpareServers 10
StartServers 5
MaxClients 200

Set the paramters to these values if they are higher than the ones above stated.

5. To check whether the error is actaully removed empty error_log using
echo > /usr/local/apache/logs/error_log

6. restart apache manually.
7. check error_log using.
grep "FD_SETSIZE" /usr/local/apache/logs/error_log

8. To check apache server status you can turn on the server-status from httpd.conf

<Location /servername-status>
SetHandler server-status
Order allow,deny
Allow from all
Allow from localhost
Allow from ".serverhostname"
</Location>

Replace the servername above with your server name and server host name with server&#39;s host name.
You can access it using http://ipaddress/servername-status
This URL should need kept confidential.
8. restart httpd.