How to make the WF4 Batch Worker Autostart

Today on endpoint.tv I showed how to create a workflow service that can do background work on a scheduled basis (The sample code is posted here).  In the example I showed a web UI that allows you to start the job by clicking on a submit button.

Somebody asked me if there was a way to do this without a human starting the process.  They wanted the system to automatically start the process whenever the app started up.

Yes there is a way and here is how you can do it.  I decided to add some settings to web.config that would allow you to create an auto start counter.

Add the following to web.config

<configuration>

  <appSettings>

    <!-- The following will cause a batch process to start counting when the app auto-starts. -->

    <!-- The format is (count to)|(delay)-->

    <add key="AutoCount" value="1000|10"/>

  </appSettings>

Add the following code to the Global.asax.cs file in the Application_Start method

private void Application_Start(object sender, EventArgs e)

{

    // Code that runs on application startup

    string autoCount = ConfigurationManager.AppSettings["AutoCount"];



    if (string.IsNullOrWhiteSpace(autoCount)) return;



    var values = autoCount.Split('|');



    // Check for valid value

    if (values.Length != 2)

        return;



    int count;

    if (!Int32.TryParse(values[0], out count)) return;



    int delay;

    if (!Int32.TryParse(values[1], out delay)) return;



    var request = new BatchRequest

                        {

                            CountTo = count,

                            Delay = TimeSpan.FromSeconds(delay),

                            StartAt = DateTime.Now

                        };



    var proxy = new BatchWorkerClient(new NetNamedPipeBinding(), new EndpointAddress("net.pipe://localhost/BatchWeb/BatchWorker.xamlx"));

    try

    {

        var response = proxy.SubmitJob(request);

        proxy.Close();

    }

    catch

    {

        proxy.Abort();

        throw;

    }

}

Then using IIS manager do the following

Enable named pipes

1. Right click on the BatchWeb site and select Manage Application / Advanced Settings
2. Add net.pipe to the list of enabled protocols

Enable Auto-Start

1. Right click on the BatchWeb site and select Manage WCF and WF Services
2. On the Auto-Start tab set the app to auto start

Now when the system boots (or the app pool recycles) the system will start a counting job.  You might want to include a way to check and see if the batch work is already in process before starting another one.  My code always starts up a new one.