title: Nginx caching: tag-based cache-busting like Varnish Hashtwo
body: <p>We're about to set up a cache and reverse proxy for our site, and we're deciding whether to use Varnish or Nginx. We have complex cache-busting requirements, and we effectively require surrogate key (or tag-based) cache invalidation.</p>
  
  <p>Varnish offers <a href="http://book.varnish-software.com/4.0/chapters/Cache_Invalidation.html" rel="noreferrer">Hashtwo</a> with this functionality. Does Nginx offer this in any form?</p>