title: The behavior of varnish on MISS
body: <p>Consider this scenario:
  The Varnish cache has a MISS and the backend server is now regenerating the requested content. During the generation time a second request comes in and also gets an MISS. Does varnish send this request to the backend while the other request is pending? What if thousand requests come in between this time. Server would crash right? Every request would make it slower.</p>
  
  <p>Is this correct or is varnish "synchronizing" those scenarios to prevent such a problem?</p>
  
  <p>Thank you in advance!</p>