title: Stale-while-revalidate cache replacement from Varnish
body: <p>We are currently moving our servers to a new one, with PLESK 12.5 which doesn't support Varnish cache for our PHP applications.</p>
  
  <p>We use Varnish, mostly for the 'stale-while-revalidate' capability, so that we can send whole pages or parts (using ESI) without any waiting time for any customer while cache is refreshing.</p>
  
  <p>Is there any alternative to Varnish for a similar kind of cache ? Either another "program" that could run on PLESK, or any PHP/server cache ?</p>
  
  <p>PLESK comes with NGINX, but it does not seem to provide 'stale-while-revalidate' capabilities ; I also know Squid isn't supported on PLESK. </p>