#!{{ python_executable }}print """<h1>HTTP cache performance</h1><p> Web pages rendered by a CDN speed up a web site significantly. It is required to have a CDN mainly for frequented web sites in order to have a high availability for internet users.</p><p> If a web site is not well served, the backend will then take care of the client request by calculating the response, which takes calculation time and may slow down all other asynchronous server operations.</p><p> However, if a web site needs to serve different data to authenticated users, caching is difficult. As web pages loads components that can be cached, the ones which are also loaded by anonymous user pages can easily be cached for one hour for stylesheet, javascript and image files. Even better if they are static files, so their cache duration can be increased to one year.</p><h2>Wrongly cached web pages list</h2><p> This shows some web pages cache state by checking TrafficServer or Squid HTTP headers. (Last update: XXX.)</p><p>(TODO)</p>"""