Web roles under IIS Classic pipeline mode for backward compatibility

If you have been involved in moving ASP.NET 2.0 Web applications to Windows Azure, you probably have faced some compatibility issues related with the IIS Pipeline mode used by default in a web role.

Windows Azure by default uses integrated mode, but for the sake of simplicity, in some migration scenarios, you could also use Classic mode, that will give you the chance to keep your components as they are.

In order to do that, follow the next steps:

• You need to add a reference to the library Microsoft.Web.Administration.dll

• You need to override the OnStart event and add the following code:

   

  Imports System

  Imports System.Collections.Generic

  Imports System.Linq

  Imports Microsoft.WindowsAzure

  Imports Microsoft.WindowsAzure.Diagnostics

  Imports Microsoft.WindowsAzure.ServiceRuntime

  Imports Microsoft.Web.Administration

   

  Public Class WebRole

  Inherits RoleEntryPoint

   

  Public Overrides Function OnStart() As Boolean

   

  'Configure Azure Tracing

  ConfigureTracing()

   

  'Configure Azure Pipeline

  SetClassicIISPipelineMode()

   

  Return MyBase.OnStart()

   

  End Function

  ''' <summary>

  ''' Set IIS Pipeline mode to Classic

  ''' Only use that method when the app needs backward compatibility

  ''' </summary>

  ''' <remarks></remarks>

  Private Sub SetClassicIISPipelineMode()

   

  Dim srvManager As New ServerManager()

   

  Try

  Trace.WriteLine("SetClassicIISPipelineMode starting...")

   

  Dim appSite = (From site In srvManager.Sites

  Where site.Name.Contains(RoleEnvironment.CurrentRoleInstance.Role.Name)).FirstOrDefault()

  If Not appSite Is Nothing Then

  Trace.WriteLine("AppSite reference retreived")

  Dim appPool = (From pool In srvManager.ApplicationPools

  Where pool.Name = appSite.Applications(0).ApplicationPoolName).FirstOrDefault()

  If (Not appPool Is Nothing) Then

  Trace.WriteLine("AppPool reference retreived. Changing mode...")

  appPool.ManagedPipelineMode = ManagedPipelineMode.Classic

  srvManager.CommitChanges()

  Trace.WriteLine("Changes Commited")

  End If

  Else

  Trace.WriteLine("Unable to get AppSite reference")

  End If

   

  Catch ex As Exception

  Trace.WriteLine("SetClassicIISPipelineMode Exception: " + ex.ToString())

  Finally

  srvManager.Dispose()

  End Try

  End Sub

   

   

  Private Sub ConfigureTracing()

  System.Diagnostics.Trace.Listeners.Add(New Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener())

  'The Config is Done using the diagnostics.wadcfg file

  End Sub

   

  End Class

 

And that's it, after these changes, your application will run under IIS classic pipeline mode and you won't have to modify any of your components based on classic pipeline mode.

Comments

• Anonymous
  September 28, 2011
  Hello Gonzalo, I have tried above code but its not working. The pipeline is still set to integrated mode. Can you upload sample project achieving the same result Regards Shashank

• Anonymous
  September 28, 2011
  Hello Gonzalo, I have tried above code but its not working. The pipeline is still set to integrated mode. Can you upload sample project achieving the same result Regards Shashank

• Anonymous
  October 02, 2011
  Hi Shashank , Please be sure that you are deploying to the Management library. Also if you are using multi-sites the following code may change : Dim appSite = (From site In srvManager.Sites Where site.Name.Contains(RoleEnvironment.CurrentRoleInstance.Role.Name)).FirstOrDefault() If you debug the code in the devfabric, are you seeing any error ? Does it work in the Dev Fabric? Regads. Gonzalo.