title: iis7 application pool hanging
body: <p>I have a .net 4.0 website that was running on physical Windows server 2003 boxes on IIS6 32bit just fine.  We have migrated to new virtual servers running Windows Server 2008 32 bit with IIS7.  The application pool is running in classic mode.</p>
  
  <p>Since the move, I at random get a situation where the application hangs.  The request queue rockets and then I get 503 errors.  If the application pool is recycled, then the error goes away till the next time it occurs.</p>
  
  <p>There are no entries in the event logs relating to it except that it notes when the application pool took to long to shut down during the recycle process.  I have reporting in my .net application that logs to a DB and sends me errors but it sends me nothing when this application is hanging.</p>
  
  <p>What tools can I use to diagnose the problem and figure out what is causing it?</p>