title: Nested ASP.NET activities for independent requests
body: <p>I have a trace like this done by perfview: </p>
  
  <p><a href="https://i.stack.imgur.com/uPGu0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uPGu0.png" alt="perfview trace"></a></p>
  
  <p>It should be taken with 'Thread time' switch. What I don't understand is why the activities are nested like this. I'm pretty sure that requests for the files are independently made by a browser and there is no relation between them. Basically the files should be cached. So the byte array is just copied asynchronously to the output stream.</p>
  
  <ul>
  <li><strong>Why are the activities nested?</strong></li>
  <li><strong>Also what might that UNKNOWN_ASYNC in mycontext mean?</strong></li>
  </ul>
  
  <hr>
  
  <p>Edit: added sshot from production with much less usage. </p>
  
  <p><a href="https://i.stack.imgur.com/zJ51n.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zJ51n.png" alt="production server"></a></p>
  
  <p>I suspect that my question is somehow related to performance testing. I'll try to reproduce this behaviour under a load.</p>