In this article I would like to summarize the storage methods we learnt in Windows Azure. The advanced features are also discussed here.
Types of Storage
Recollecting that we have 3 types of storage in Windows Azure:
- Local Storage
- Windows Azure Storage
- SQL Azure Storage
Below are some of the advanced storage features.
Local Storage Features
This is a temporary storage and the application cannot see the underlying disk or drive on which the storage is done. But the application can request up to 1 GB of data on the local storage.
The local storage space is not accessible outside or to any other instances. Windows Azure on the runtime chooses the best drive to store the data.
Windows Storage Features
The Windows Azure operating system allows 4 kinds of storage which are Blob, Table, Queue and Disk storage.
These storage accounts are publicly exposed so we can access they from virtually anywhere. The storage account data is exposed using HPTTP, REST and OData protocols.
The Blob storage provides huge amount of data manipulation. The table storage provides structured data processing as entities and Queue storage is efficient in back end and front end communication.
In Windows Azure Storage there is one more type called Drive storage. Windows Azure Drive allows us to upload Virtual Hard Drives as Blob. This provides great flexibility to developers. More information can be found here.
Automatic Replication is a feature that makes sure the data stored is replicated 3 times. This is taken care by the Content Delivery Network (CDN) and improves the performance.
Geo-replication is a new feature that provides replication for Blob and Table data at no additional cost. This provides the reliability during a crisis situation.
Queue Insert Message Timeout is a new feature that makes the queue message invisible until the specified time expires.
Table Query Projection is a new feature that allows partial reading of entity’s properties. This will improve the performance.
REST and Managed APIs support working with storage services. We need to download the REST API SDK to achieve this.
Pricing of Windows Azure Storage is performed based on the average usage of blob, table, queue and drive storage.
The updated information can be found here.
SQL Azure Storage Features
SQL Azure represents Cloud version of SQL Server. It is a highly available and scalable database on the cloud premises.
SQL Azure provides ease of use and maintenance. No need of installation and applying patches as these activities will be taken care by the provider.
ADO.NET, ODBC and JDBC providers are supported on SQL Azure.
The design time structure and data management can be done through:
- Windows Azure Portal
- SQL Azure Management Portal
- MMC Tool
- SQL Server Management Studio
The SQL Azure provides automatic replication of data and automatic switching of the server in case of failures.
Some of the current drawback of SQL Azure is:
- Not all data types in SQL Server are supported
- SSAS (SQL Server Analysis Services) not supported
- Service Broker feature not supported
The editions in SQL Azure are the following:
- Web Edition
- Business Edition
The web edition can support 1 GB or 5 GB in size and good for small Web applications. The business edition can support up to 50 GB of data and good for independent software vendors and enterprise applications.
The layers in SQL Azure would be the following.
- Client Layer
- Services Layer
- Platform Layer
- Infrastructure Layer
The Client layer is hosted in windows azure and communicates with our application. The Service layer acts as a gateway between the client layer and the platform layer. The Platform layer includes the physical servers which supports the service layer. The Infrastructure layer consists of the IT administration of the physical hardware and operating systems that supports the service layer. More information can be found here.
In this article we have summarized the types of storages in Windows Azure and the advanced features provided by them.