title: How do I prevent static member variables from being accessed by more than one request at a time in IIS?
body: <p>I’m having some trouble with understanding how IIS  is handling static variables on its threads.  My understanding has always been that if IIS has 4 worker processes that it can handle 4 requests simultaneously and that it would be the same as having 4 separate threads running the website.  Any static variables would persist in each individual thread.  The reason I’m a bit confused is that I have a scope that I’ve made which manages connections and caching transactions.  When I’m testing the app I don’t notice any issues but after I’ve compiled it and hit it at the same time from two different locations I seem to get a sort of conflict.  Now if these worker processes are separate why would this be?  Can more than one request be processed on a single worker thread at the same time?  This is tremendously important as there are unique ID’s that are held in these static members to handle escalation of the objects that manage these functions and it appears that they are trying to access the same object.</p>
  
  <p>I'm running this on Vista's IIS server on an x64 machine.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>For values that need to persist through the thread on a single request, I put these values into <code>Web.HttpContext.Current.Items</code> which seems to do the trick.</p>
  
  <p><code>&lt;ThreadStatic()&gt;</code> can be used but it may not be available during the entirity of the request process.  In one module that I have,  is only used on a variable to indicate if that thread has already loaded the settings for the cahcing server.  If true then the tread (not asp.net) is ready to fetch data from the caching server.</p>