Windows Azure, an operating system for the cloud

Think of the computer on your desk today. When you write code for that computer, you don�t have to worry about which sound card it uses, which type of printer it�s connected to, or which or how many monitors are used for the display. You don�t worry, to a degree, about the CPU, about memory, or even about how storage is provided (solidstate drive [SSD], carrier pigeon, or hard disk drive). The operating system on that computer provides a layer of abstraction away from all of those gritty details, frees you up to focus on the application you need to write, and makes it easy to consume the resources you need. The desktop operating system protects you from the details of the hardware, allocates time on the CPU to the code that�s running, makes sure that code is allowed to run, plays traffic cop by controlling shared access to resources, and generally holds everything together.

Now think of that enterprise application you want to deploy. You need a DNS, networking, shared storage, load balancers, plenty of servers to handle load, a way to control access and permissions in the system, and plenty of other moving parts. Modern systems can get complicated. Dealing with all of that complexity by hand is like compiling your own video driver; it doesn�t provide any value to the business. Windows Azure does all this work, but on a much grander scale and for distributed applications by using something called the fabric.

Windows Azure takes care of the whole platform so you can focus on your application. The term fabric is used because of the similarity of the Azure fabric to a woven blanket. Each thread on its own is weak and can�t do a lot. When they�re woven together into a fabric, the whole blanket becomes strong and warm. The Azure fabric consists of thousands of servers, woven together and working as a cohesive unit. In Azure, you don�t need to worry about which hardware, which node, what underlying operating system, or even how the nodes are load balanced or clustered. Those are just gritty details best left to someone else. You just need to worry about your application and whether it�s operating effectively. How much time do you spend wrangling with these details for your on-premises projects? It�s probably at least 10�20 percent of the total project cost in meetings alone. There are savings to be gained by abstracting away these issues.

In fact, Azure manages much more than just servers. There are plenty of other assets that are managed. Azure manages routers, switches, IP addresses, DNS servers, load balancers, and dynamic virtual local area networks (VLANs). In a static data center, managing all these assets is a complex undertaking. It�s even more complex when you�re managing multiple data centers that need to operate as one cohesive pool of resources, in a dynamic and real-time way.

If the fabric is the operating system, then the Fabric Controller is the kernel.

Source of Information : Manning Azure in Action 2010