How to (pre)start xamlx workflow service

Question

Related to this question.

I have a xamlx workflow service that loads part of its definition from a database when it runs (using ActivityXamlServices.Load). Reason for this is that I need versioning, see the related question. I'll use WCF routing to direct calls to the right service.

The part that I load dynamically contains a Receive activity. However, this activity is 'invisible' as long as the workflow doesn't start because the part of the workflow I load from the database is only loaded when the workflow starts. So from the outside it appears as if there is no Receive activity in the workflow.

Apart from not being able to generate a contract for the workflow service, I can't call the service either. My first attempt was to do a soap call with the right contract on the workflow service. However, the runtime doesn't automagically activate my workflow in that case. So the question is, how do I start a workflow that is hosted inside IIS?

Answer 1

There is a relatively new module for IIS 7.5 called Application Warmup. This is a configurable tool that allows IIS to start up your application w/ varying degree's of configurablity. I suggest checking out these two links:

http://www.iis.net/download/ApplicationWarmUp

http://learn.iis.net/page.aspx/688/using-the-iis-application-warm-up-module/

Answer 2

Windows Server AppFabric includes an Auto Start feature that will help.

Check out How to create a WF4 WorkflowServiceHostFactory for AppFabric Auto-Start

I also have a sample that shows how to load XAMLX from a database with a Virtual Path Provider at Windows Workflow Foundation (WF4) - Workflow Service Repository Example