I am trying to debug some slowness in a site and I discovered that KeepAlive was disabled and that most of the content was being served with Connection: close. After enabling KeepAlive, most of the pages started to serve Connection: keep-alive headers but now I have noticed that some of the static JavaScript files are being served with no Connection header at all.
Is it likely that Apache is not sending a Connection header for application/x-javascript? Or is there some other reason that would make Apache not send a Connection header for the static JavaScript files? It looks to be sending a Connection header for image/gif just fine...