Windows Azure: Creating and Deploying Worker Role

Creating a Worker Role

In this article we are creating a worker role using Visual Studio 2010. This will make the reader familiar with Windows Azure. After that the role is deployed into the online portal.

Open Visual Studio 2010 and use the command New Project. From the appearing dialog box select the Windows Azure Project option from the Visual C# group.



Enter an appropriate name for the project and click Ok to continue. Now you will be prompted with another dialog for selecting the type of project.

Double click on the Worker role option to select a worker role project and click the Ok button.



Now you are ready with the Worker role project.

Purpose of Worker Role

The Worker role can be used to host WCF services, provide endpoints, perform operations etc.

The default Run() method implementation contains an infinite loop as shown below:

 public override void Run()
        {
            // This is a sample worker implementation. Replace with your logic.
            Trace.WriteLine("WorkerRole1 entry point called", "Information");

            while (true)
            {
                Thread.Sleep(10000);
                Trace.WriteLine("Working", "Information");
            }
        }

Now execute the application and you will be able to see the application inside the browser. From the system tray, you can verify the Windows Azure Emulator is running.

If successfully executed, you can see the trace output messages as shown below.



Exceptional Cases

Deploying the Worker Role

After developing the Worker Role, we have to package it and deploy to the cloud. The entire steps in this are:

• Create Worker Role

• Create Package

• Deploy to Cloud

Creating the Worker Role is already done. Now we need to do the following steps.

Create Package

For creating the package, right click on the project context menu and click Package.



Now as dialog box will be appearing, leave the default options selected and click the Package button on the dialog.



After performing the packaging, the folder containing package is opened in a new explorer window automatically.



There are two files in the folder as shown above:

• Configuration File

• Service Package File

The Configuration file contains the instance count, application setting entries etc.

Deploy to Cloud

The deploying part contains deploying the package file and the configuration file. For deploying the files, we need to sign in to the Windows Azure Portal.

After signing in, click on the New Hosted Service button from the left top panel. The following dialog box appears.



Detailing Input Fields in Dialog Box

The subscription list automatically selects the default subscription (trial).

In the service name text box, enter a name for the service.

In the service URL prefix text box, enter a unique prefix name.

In the region, select an appropriate region of deployment.

Enter an appropriate deployment name in the final text box.

Select Package

Now, we need to specify the Package location and Configuration file. Use the Browse locally… button for these and select the files from your local machine.

After specifying all the inputs, click the Ok button. (In case of instance warning box, click Yes to override it for time being)

Now you can see that the entry is shown as preparing to upload in the list.



Waiting for Upload Operation

We need to wait a few minutes for the upload operation to be completed. After the upload operation is completed the instance will be started.

After all the operations are completed the status will turn to ready as show in the image below:



Getting the Deployed Url

The DNS name specifies the url to access the worker role as shown below:



For viewing the deployed Worker Role traces we need to change the trace configuration. This will be discussed later.

Warning

As the worker role we uploaded is having infinite loop, it will be quoting computing resources and any usage beyond monthly free limit will be charged to the credit card. So it is recommend you to delete the deployed worker role after the test.

Deletion is explained below.

Deleting the Worker Role

As mentioned already, any computing hours excess of the trial limit will be charged. So we need to ensure that the instances are stopped and deleted. The steps are depicted below:

Step 1: Stopping an Instance

Sign in to the Windows Azure Portal, click the Hosted Services link to vie the hosted services and click Stop from the toolbar.

The order of clicking is depicted as sequence.



Step 2: Deleting an Instance

Once the instance is stopped, click on the Delete button to delete the instance. (This is for demonstration and one may keep the instance if it is needed in future)



On clicking the Delete button you will be prompted with a confirmation dialog.



Click on the Yes button for proceeding with the Delete operation. Now you can see the status being changed to Deleting…



After the operation is completed, the above entries are removed from the list. So it confirms the Delete operation.

Summary

In this article we have seen how to create, package, deploy and delete a Worker Role to windows azure hosting.