title: How ETags are generated and configured?
body: <p>I recently came through the concept of <code>ETag</code> HTTP header. (<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag" rel="nofollow noreferrer">this</a>) But I still have a problem that for a particular HTTP resource who is responsible to generate ETags?</p>
  
  <p>In other words, it is actual application, container (Ex:Tomcat), Web Server/Load balancer (Ex: Apache/Nginx)?</p>
  
  <p>Can anyone please help?</p>