As we said in our previous post in this series, in the Windows Azure platform there are three main components, Windows Azure, Windows Azure platform AppFabric and SQL Azure. Additionally within Windows Azure server are two environments:

  • The compute environment which processes request and
  • The storage environment that holds data reliably

Also in Windows Azure there is an internal subsystem, Windows Azure Fabric Controller, which is not the same as the Windows Azure platform AppFabric. The Windows Azure Fabric Controller manages the compute and storage resources. It also deploys services and monitors the health of those deployed services. In the event that a service should fail, the Fabric Controller provides the resources necessary and re-deploys the service.

Within the Windows Azure platform AppFabric there are two services. First, there is the service bus. Through this service applications and services can be connected no matter where they may be located. The Service Bus makes available common message and communications methods such as events, one-way messages, remote procedure calls and tunnels for streamed data. Secondly, there is the access control service that supervises identity in REST-based services that use the cloud and also implements a token-issuing service.

SQL Azure is a subset of Microsoft’s SQL Server and provides a relational database for the cloud. It is not the same as Windows Azure storage services.

Finally Windows Azure contains diagnostics services for overseeing an application’s health.

The management and storage subsystems in Windows Azure all utilize the REST-based interfaces and are not dependent on the .NET framework or on Microsoft Windows. They respond to HTTP or HTTPS requests. In our next post, we will look at the Windows Azure compute environment.

Are you interested in getting started with the Windows Azure platform? Then visit Also, you can try out Windows Azure for free with the 30-day Windows Azure Platform Pass.