title: should we close the connection of a pre-flight Cors request while sending response?
body: <p>As I know that if cors request comes with some extra headers set, first server needs to process it.</p>
  
  <p>With CORS, the server must send the Access-Control-Allow-Headers header to allow uncommon request headers from the client. </p>
  
  <p><strong>Access-Control-Allow-Headers ... - Comma-delimited list of the supported request headers.</strong></p>
  
  <p>e.g suppose my pre-flight request is</p>
  
  <pre><code>OPTIONS /cors HTTP/1.1
  Origin: http://api.bob.com
  Access-Control-Request-Method: PUT
  Access-Control-Request-Headers: X-Custom-Header
  Host: api.alice.com
  Accept-Language: en-US
  Connection: keep-alive
  User-Agent: Mozilla/5.0...
  </code></pre>
  
  <p>Then from server-side I will send response</p>
  
  <pre><code>Access-Control-Allow-Origin: http://api.bob.com
  Access-Control-Allow-Methods: GET, POST, PUT
  Access-Control-Allow-Headers: X-Custom-Header
  Content-Type: text/html; charset=utf-8
  </code></pre>
  
  <p>My question is - 
  should I close the connection on server side while we send pre-flight response to client?</p>
  
  <p>One more thing how can I cached pre-flight request for all other distinct subsequent requests?</p>
  
  <p>Thanks</p>