Windows Azure platform is created to help developers write, distribute and
manage Web application and Web services on the Internet. Azure provides
on-demand computation and storage services that allows Web applications to scale
them on Internet simply by changing the configuration parameters. Azure is an
operating system for the cloud, using which developers can host and manage their
applications as services on Windows Azure platform.
Windows Azure supports both Microsoft and non-Microsoft languages and
environments -developers can use Ruby, PHP, and Python to develop Azure
Services. Azure supports a seamless development experience and is well
integrated with Visual Studio.
Direct Hit! |
Applies To: .NET Developers USP: Build apps for cloud Primary Link: www.microsoft.com Search Engine Keywords: Windows Azure |
Setting up development environment in Visual Studio
You can download the Azure SDK and Azure tools and use them in Visual
Studio. In order to create an Azure application, the pre-requisite operating
systems are Windows Vista with SP1, Windows Server 2008 or Windows 7. You would
also need .NET framework 3.5 with SP1 installed. Additionally, the development
machine should be configured with IIS 7 (with ASP.NET and WCF HTTP Activation).
Also it requires Microsoft SQL Server (or express) 2005 or 2008.
To develop Windows Azure application you would need either of the following:
MS Visual Studio 2008 SP1, MS Visual Studio 2010 Beta 1 or MS Visual Web
Developer 2008 Express Edition with SP1.
Once you have the required IDE, you will need Azure SDK and Azure tools for
Visual Studio to start developing your first Azure application.
Clicking on 'File->New Project' in Visual Studio will display Project Template for creating Cloud Application. |
Windows Azure Tools for MS Visual Studio extends Visual Studio 2008 and
Visual Studio 2010 Beta 1 to enable creation, building, debugging, and running
of applications on Azure. To obtain this SDK and the tools, go to www.microsoft
.com/download and search for 'Windows azure tools'. The file to be downloaded is
VSCloudService.exe that will install both Azure SDK as well as Azure tools in
your Visual Studio Shell. Once you have installed the tools, you will see that a
new project type has been added to your Visual Studio. See the image below.
A Cloud solution consists of two projects. Here, 'forPCQuest' and 'WebRole1' are two projects added to Visual Studio Solution file. |
Clicking on 'File->New Project' in Visual Studio will display Project Template for creating Cloud Application. |
Creating Cloud application in Visual Studio
Creating a new Cloud Service project in Visual Studio will create two
projects for you in the solution (see second image). If you look into the
Solution Explorer, the first project is (forPCQuest) where application
configuration setting for Cloud is stored. Other project is a simple ASP.NET web
application (WebRole1). Service Definition (.cscdef) file in the first project
is used to provision Web application 'as a Service' for cloud. To achieve this,
the XML tag used is:
Once the Web Application is added as a service as mentioned
above, we can set configuration settings for our Web Application in Service
Configuration file (.cscfg). If you open Service Configuration file, you will
see the following code:
This file describes what setting your web application will
use when deployed on the cloud. Checkout the instances count setting, for
example, that allows you to configure the scalability requirements. This is
interesting to see how you can dynamically increase the load capacity of your
web application on-demand. This is one of the promises that Windows Azure
delivers.
Now, let's open our Web application (WebRole1) and make
some changes in it. If we open Defualt.aspx file and add the line:
Welcome PC Quest Reader
In order to build our application, we can right click and
select Build or directly select Publish option that will first build the
application and then attempt to publish it (see the above image). If we select
the publish option, it creates a 'publish' directory somewhere at the same place
where the project source files are stored and creates two files. These files are
1. Service package file which has our Web Application in Cloud deployable
format, and 2. Cloud Service Configuration file which consists of configuration
settings for Cloud that our Web Application will use. Also, the Visual studio
will automatically open browser and point to a URL https://windows. azure.com/Cloud/
Provisioning/Default.aspx where you can provision your small Cloud application
that you have just built.
A cloud application can be hosted on windows.azure.com. The first step is to define a URI on Internet so that your cloud application gets a Unique Internet address. |
You may like to test your application locally on your
machine before you deploy it to http://windows.azure.com. In order to do that,
just select the Cloud project and hit 'Ctrl + F5'. You will notice two small
icons on the right side of your status bar — these are 'Development Fabric'and
'Development Storage'. These are nothing but a local implement of Windows Azure
with all the necessary services to deploy and test a Cloud application locally.
Preparing for deployment at windows.azure.com
Microsoft is hosting Windows Azure as a free service for people to host
their Cloud applications at http://windows. azure.com . It requires you to first
register on the site and thereafter a token for Windows Azure trial is sent to
you in your email. Once you receive this token, you can create a blank Azure
project on windows. azure. com. After a blank project is created, you need to
add a 'Hosting Service' to your Azure project (see image 4)
A cloud application is first deployed to 'Staging' environment, tested, and then moved on to 'Production' environment. |
While creating a 'Hosted Service' you will be required to
have a unique name by which your service will be identified on Internet. The
full name of the service will be http://yourUniqueName. cloudapp.net
Uploading your Package and Cloud configuration file to
Windows Azure
In the Hosted Service you just created, now you can deploy your files that
you created using Visual Studio. You have to first deploy them on Staging before
you can promote them to production.
Click on the Deploy button and upload the files from
'update' directory.
Type the URL of your Cloud Application in any browser and hit Enter. You will be able to see your first Cloud application running. |
First your application is deployed to staging environment
where you can do testing and verification. In staging environment, it allocates
a temporary URL on web to work with. After you are satisfied with your
application behavior in Staging, you can promote it to production. While you
deploy your application to Staging or Production, please wait for few minutes
before it shows a green 'started' icon in front of web role. Only after the
'started' status appears, you will be able to launch your application from the
'Web Site URL' links
You have successfully created and deployed your first Cloud
application on Widows Azure. You can visit the URL: http://pcquest. cloudapp.net/
and see the same application deployed there. (See the last image)
Vivek Goyal, Developer Technology Specialist, Microsoft India