Application Pool Modes

Application Pool Modes

Classic Application Pool Mode

  • IIS 7 handles requests to the worker process the same way as in IIS 6.0 isolation mode
  • ASP.NET requests first go through native processing steps in IIS and are then routed to Aspnet_isapi.dll for processing of managed code in the managed runtime
  • Finally, the request is routed back through IIS to send the response
  • Some processing steps, such as authentication and authorization, are duplicated
  • Managed code features, such as Forms authentication, are only available to ASP.NET applications or applications for which you have script mapped all requests to be handled by aspnet_isapi.dll
  • Only assign an application to Classic mode if the application fails to work in Integrated mode

Integrated Application Pool Mode

  • Uses a new architecture that combines the request-processing models of IIS and ASP.NET
  • Requests to the worker process pass through an ordered list of events
  • Each event calls the necessary native and managed modules to process portions of the request and to generate the response
  • Eliminates duplicate authentication and authorization steps
  • Enables the availability of managed features for all content types, i.e. involves ASP.NET in all page requests,including .txt and .html files, not just .aspx files.  Sitecore cannot process requests that IIS does not process using ASP.NET

Sources