When calling BeginInvoke on a delegate, the action is executed on a separate thread. If called in ASP.NET does it use a CLR worker thread? Or does it use an IIS worker thread?
If the latter, then I will need to employ an asynchronous ASP.NET pattern to ensure the action is executed on a CLR worker thread. But I would rather not do that if the action ends up there upon BeginInvoke.
it uses a CLR worker thread.
as described in here
To begin with, ASP.NET uses the process-wide CLR thread pool to service requests (for more background on the CLR thread pool, see the .NET column in this issue).
EDIT:
another resource is this blog
Unfortunately, the thread used by BeginInvoke is actually taken from the same worker thread pool that is used by ASP.Net to handle Page Requests
Thread usage/management is a bit different in IIS6, IIS7 and IIS 7.5.
Pretty detail and updated explanation here:
ASP.NET Thread Usage on IIS 7.5, IIS 7.0, and IIS 6.0
Not sure if this answers your question but a good read anyways.
Using a custom delegate and calling its BeginInvoke method offer a quick way to fire off worker threads for your application. But unfortunately, they hurt the overall performance of your application since they consume threads from the same pool used by ASP.NET to handle HTTP requests.
Just remember too, if the callback from the Asynchronous method is important then, you need to block the main thread from returning to the client until the asynchronous process has completed. If the logging and analytics is a 'fire-and-forget' method call, then things are easier and you can just fire off the method and allow the server to respond to the client. However, if the callback is important and the server has completed processing, nothing is happening on the server to handle the callback once completed; this is where asynchronous processing on the server for ASP.NET applications differs from say a WinForms application.
