There are a couple common ways of storing data when using Microsoft Windows Azure. One is SQL Azure, which is a cloud-based version of Microsoft SQL Server. The other is Azure storage. SQL Azure will be familiar to those who already understand relational databases. It may also make moving an application to cloud easier, if that application already uses SQL Server.
Azure storage has some advantages as well. First it is inexpensive. Azure storage costs about 15 cents per gigabytes per month, compared to $10 per gigabyte per month for SQL Azure. It can also be very large. Depending on your instance size, it can be up to 2 terabytes. It is also cross-platform, and accessed using standard internet requests.
There are four types of Azure storage: blob storage, table storage, queue storage and Azure drives.
Blob storage is used to store binary data. This could be pictures, videos, or any other binary data.
Table storage is used to store structured data. It is similar to a database, but not relational. Table storage is a convenient way of saving business entities in an object-oriented program. In many ways it is simpler than relational storage.
Queue storage provides a simple messaging system that allows different Azure roles to communicate. For example, a user may request a report to be run using an application running in a Web role. That request could be sent to an Azure queue. Later a worker role can process the request, and then email the completed report to the user.
Azure drives allow storage to be access using standard NTFS APIs. This could be particularly useful if you have an application that already writes to a hard disk and you want to migrate it to the cloud.
If you’re using .NET though, accessing storage is made easier using the Azure SDK. If you don’t already have it, go to this link, http://www.microsoft.com/windowsazure/windowsazure/, and then click on the “Get tools and SDK” button. You might also like to read this article, Windows Azure Training Series – Setting up a Development Environment for Free.
Once you have the SDK installed, set a reference to Microsoft.WindowsAzure.StorageClient.dll, and you’re ready to go.
In later posts, we’ll take a look at some code to write to Azure storage. In the meantime, you might like to read the prior posts in this series.
You might also like to come to Learning Tree course 2602, Windows Azure Platform Introduction: Programming Cloud-Based Applications.