Have you ever seen this dreaded message in your Apache/HTTPD /var/log/httpd/error_log?
[error] server reached MaxClients setting, consider raising the MaxClients setting
The error itself is slightly misleading. Ibelieve this happened to one of my servers, I found Apache was running still, and that you could telnet to port 80 but no respnose would be given.
For some reason my error log initially did not have the above error, but after a restart I saw........