MaxClients in Apache2 is a canary for other vhost logging misconfiguration

I first noticed a problem when the browser started timing out with the message “Establishing Secure Connection”.

I checked Apache’s log at /var/log/apache2/error.log and found the following

[error] server reached MaxClients setting, consider raising the MaxClients setting

I knew at 12:30 am I wasn’t getting that many legitimate users. I noted my other_vhost_access.log were getting huge and showing the following spam. – – [29/Mar/2014:00:16:50 -0500] “GET HTTP/1.0” 200 0 “” “Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv: Gecko/20100824 Firefox/3.6.9” – – [29/Mar/2014:00:16:50 -0500] “GET[CACHEBUSTER]&pubclick=[INSERT_CLICK_TAG] HTTP/1.0” 302 0 “” “Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; en) Opera 11.00”

I disabled logging by commenting out the line in /etc/apache2/conf.d/other_vhost_access_log.