title: Web site takes unusually long time to start the first time it is accessed, (Up to 68 seconds in total)
body: <p>I have an ASP.Net application that takes an unusually long time to start up the first time it is accessed.  I did some tracing and I found that 57 seconds are spent in this function:</p>
  
  <p><code>Boolean System.Web.Compilation.WebDirectoryBatchCompiler.CompileNonDependentBuildProviders(ICollection)</code></p>
  
  <p>and that function in turn calls the following one 6 times: </p>
  
  <p><code>Void System.Web.Compilation.WebDirectoryBatchCompiler.CompileAssemblyBuilder(AssemblyBuilder)</code></p>
  
  <p>My question is what does <code>System.Web.Compilation.WebDirectoryBatchCompiler.CompileAssemblyBuilder</code> do?  My web application is already compiled, I don't know why it is doing any kind of compilation work on start-up.  Is this normal?  Is there something going on that I don't know about?</p>