Overview
Static files (index.html) can be served without logging a request in access_log.
Cause
This occurs when mod_pagespeed is enabled. Pagespeed intercepts the request higher in Apache’s processing axis before mod_log_config and serves the static file from its optimized cache if present. This does not affect files which have a Pragma: no-cache header such as with PHP files.
Solution
Disable mod_pagespeed. If visitor statistics are necessary, then consider utilizing Google Analytics which is accessible from within the panel.