We have a site configured on IIS 8.5 - example.com (for instance). This site has two bindings. For example, site.example.com and newsite.example.com. We also have HTTPS redirects on this for both bindings.
The issue is that we're trying to determine the usage of the 'old' site (site.example.com) and the new site (newsite.example.com). Howerver, in the IIS log files, the [cs-host] value only ever shows the newsite.example.com host and never the site.example.com (old site). We know people are still accessing the old site, but it's difficult to compare the numbers as we only ever see the new site in the logs. I've accessed the old site myself and cannot see that in the log files.
Is this something that is known? Does the cs-host only report whatever the most recent binding is?
As lextm mentioned, I think you need to pay attention to the redirect of your site. I test it in my side, if I create a redirect rule to redirect from "A" domain to "B" domain, the "cs-host" field will not show "B" domain in logs.