Load balancing of requests in Visual C#.NET

Maker USS Code 128 in Visual C#.NET Load balancing of requests

Because data is partitioned and replicated across multiple servers, all requests via the REST API can be load balanced. This combination of data replication, data partitioning, and a large web server farm provides you with a highly scalable storage solution that can evenly distribute data and requests across the data center. This level of horsepower and data distribution means that you shouldn t need to worry about overloading server resources.

Now that we ve covered the theory of table storage, it s time to put it into practice. Let s open Visual Studio and start storing some data.

Now that you have an understanding of how data is stored in the Table service, it s time to develop a web application that can use it. In the previous section, we defined an entity for storing the Hawaiian shirt product, and we looked at how it would be stored in the Table service. Here you ll build a new application that will manage the product inventory for the Hawaiian Shirt Shop website.

Rather than returning to the solution you built in chapter 2, here you ll develop a new product-management web page in a new web application project. Create a new Cloud Service web role project called ShirtManagement. If you need a refresher on how to set up your development environment or how to create a web role project, refer back to chapter 2. Like the other storage services, communication with the Table service occurs through the REST API (which we ll discuss in detail in the next chapter). Although you can use this API directly, you re likely to be more productive using the StorageClient library provided in the Windows Azure SDK. Whenever you create a new Cloud Service project, this library will be automatically referenced. But if you re building a brand new class library or migrating an existing project, you can reference the following storage client assembly manually:

Microsoft.WindowsAzure.StorageClient In addition, you ll need to reference the ADO.NET Data Services assemblies: System.Data.Services System.Data.Services.Client

ADO.NET Data Services The Table service exposes its HTTP REST APIs through its implementation of the ADO.NET Data Services framework. By using this framework, we can utilize the ADO.NET Data Services client assemblies to communicate with the service rather than having to develop or use a custom REST wrapper. Because ADO.NET Data Services is used by the storage client SDK, you ll need to reference those assemblies too.

Now that you ve set up your project, let s look at how you can add the Product entity class to the project.

Before you create your product-management web page, you need to create an entity in the web project. At this stage, we ll just show you how to add the entity directly to the web page, but in the next chapter you ll see how to architecturally separate a class into an entity layer. To keep this example simple, we ll just store the shirt name and description, as before. Add a new class to your web project named Product.cs and define the class as shown in the following listing.

public class Product : TableServiceEntity { public string Name { get; set; } public string Description { get; set; } }

In listing 11.1, the Product class inherits from the TableServiceEntity base class (Microsoft.WindowsAzure.TableService.TableServiceEntity). This base class contains the three properties required by all table storage entities:

Now that you ve set up your project and defined your entity, you need to create a table to store the entity in. The same method can be used in both the development and live environments.

The simplest method of creating a table is to create a PowerShell script or to use one of the many storage clients that are available. In this chapter we ll use Azure Storage Explorer, which you can download from CodePlex: http://azurestorageexplorer. codeplex.com/.