18Mai/080
An ETag is not about aliens
So what is this ETag thing. I am working since 1998 in the web business but I came across ETags some weeks ago when some of my customers starting to worry about their perfomace. Don't get me wrong, out apllication worked - as always - fine, but some pages where slower as the equivalent pages at the websites of their competitors. We checked our monitoring data, it's always good to know of the webstite performed on yesterday, yesterweek or yestermonth, but were unable to find some issues. So we went from the server to the protocol and the client and checked some static and dynamic pages. As I was taking a closer look at a static webpage I stumbled over a HTTP header which I didn't know: ETag.