408 errors logged on different virtual server

This is very weird issue. I have two virtual servers, both are active in virtualmin, but one of them is now hosted elsewhere, thus it shouldn’t have anything in its access log. Today I had some problems with my server slowing down to a halt and I started checking the logs to see what is wrong. My surprise was that the site that is hosted elsewhere has a bunch of 408 reponse codes in its log, like this:

xxx.xxx.xxx.xxx - - [23/May/2014:21:53:17 +0300] “-” 408 0 “-” “-”

I found out that these are actually requests to my other website, the active one, but why are they in the wrong log? They are from valid users and not bots.

Also any idea how this could be related to the server slowdown? These started appearing at the same time with the slowdown of the server.

FYI, I updated everything two days ago, maybe that is related too?

Found it. It is related to preconnecting in browsers which apparently defaults to the first vhost in apache, in my case the website that is hosted elsewhere. The overloading was probably happening, because my MaxClients was kinda conservative. No idea why the problem surfaced now and not before. I made some tweaks to apache configuration, hopefully everything will be fine.