title: IIS7 Performance Issues for Web-services
body: <p>We are experiencing slow processing of requests under heavy load. When looking at the currently running requests during these bursts I can see many requests to our web-service code.</p>
  
  <p>The number of requests is not that large but they appear to be stuck in a preprocessing state. Below is an example:</p>
  
  <p></p>
  
  <p>We are running an IIS7 app pool in classic mode due to the need to support some legacy code.</p>
  
  <p>Other requests continue to be processed but these stuck requests gradually seem to fill up the available threads leading to slow processing of other pages.</p>
  
  <p>Does anyone have any idea on where these requests are getting stuck. </p>
  
  <p>There appears to be no resource issue with the DB and the requests state show suggest this is all preprocessing.</p>
  
  <p>We have run load tests on the code involved on local machines and can not replicate the issue.</p>
  
  <p>Another possible factor is we are making use of MVC and UrlRouting.</p>
  
  <p>Many thanks for any help.</p>