title: Random Session Timeout in ASP.NET MVC3
body: <p>i have an application which gets random session timeouts. (IIS 7.5 on Windows 2008 R2, .NET 4.0)</p>
  
  <p>i tried the following:</p>
  
  <ul>
  <li>checked the application log if the w3wp.exe process was crashed, but there is no entry.</li>
  <li>disabled in the application pool the rapid fail protection</li>
  <li>moved to the sql server state provider to be sure the loadbalancers sticky session is not 
  the problem. (we use a kemp loadmaster).</li>
  <li>ensured that no other applications use the same application pool.</li>
  <li>checked that exceptions in a thread of a called assembly is correctly handled. (simulated using throw new exception) and the error handling was correct.</li>
  <li>ensured that the validationKey and decryptionKey is set in the webconfig on all 4 webservers to the same key.</li>
  </ul>
  
  <p>i run now out of ideas how to spot this evil bug. any suggestions? i cannot reproduce the problem on my local machine in the debugger. </p>
  
  <p>one point which is maybe important, the move from page 1 to page 2 where the session loss often happens, takes sometimes more than 120 seconds, because of a third party system which is connected via tcp socket.</p>