Understanding Windows Azure

To understand Windows Azure and the Azure Services Platform, it's necessary to understand how the Microsoft Datacenters work. This article provides an overview of how Microsoft Designs their datacenters and why the Generation 4 Datacenters are so revolutionary.

The Building of DatacentersMicrosoft has been building data centers for a long time. One of the best-known services Microsoft offers is Windows Update, which delivers updates as part of their content delivery network all over the world. Now this is not the only product Microsoft's Datacenters are famous for. Other important products are Windows Live Messenger, Hotmail and Windows Live ID. Windows Live Messenger is one of the largest IM software and Hotmail is a frequently used e-mail software. Microsoft authorizes millions of users every day with their Live Services, which is used for Hotmail, Messenger and numerous other services. As you can see, Microsoft has experience building datacenters, yet so far hasn't sold products like Windows Azure.

Microsoft's G4 - Generation 4 - DatacentersMicrosoft Technology did a great job of improving their datacenters especially how they build them. Microsoft calls this the G4 - Generation 4 Datacenters. They have an industrial design - elements are standardized, which lowers the cost and enables the vendors to use templates when designing their servers for Microsoft. Generation 4 Datacenters are at heart built-in containers - yes, specifically those containers that we think about when we think about ship containers. There are major advantages to this design. Imagine a datacenter needs to be relocated. Microsoft would only need a couple of trucks and some property and the relocation is nearly done. The main advantage to this design is that server vendors just as HP or Dell know specifically what the server racks should look like by adding them in a container. If a Datacenter needs to grow, a Generation 4 Datacenter just adds some additional containers to the existing ones. Just in case, Microsoft focused on building standard tools for the cooling system so that local maintainance workers can easily get trained on the systems. It's important to note that the Generation 4 Datacenters aren't only a containerized server room. What Microsoft does with the Generation 4 Datacenters is that they improve the entire live-cycle of how the data centers are built and work. This gives Microsoft some additional benefits just as faster time-to-market and reduced costs.

Long tradition of building datacenters

Security in Microsoft's DatacentersMicrosoft has a long tradition of building datacenters and operating systems. For decades, Microsoft had to face hackers, viruses and other malware that tried to attack their operating systems. More than other vendors, Microsoft learned from these attacks and started to build a comprehensive approach to security. The document I refer to in this article describes Microsoft's strategy for a safe Cloud Computing environment. Microsoft built an online services security and compliance team that focuses on implementing security in their applications and platforms. Microsoft's key assets for a safe and secure cloud computing environment are the commitment to trustworthy computing and the need for privacy. Microsoft works with a "privacy by default" approach.

What Happens with the Virtual Machines?Figure 1 explains specifically what is going on in a Windows Azure Datacenter. I found this information in David Lemphers's blog, where he gave an overview of what happens in the datacenter. Before all else, the servers are started and a maintenance OS is downloaded. This OS but talks to a service called "Fabric Controller." This service is in charge of the overall platform management and the server gets the instruction to create a host partition with a host VM. Once this is done, the server will restart and load the Host VM. The Host VM is configured to run in the datacenter and to communicate with other VMs on a safe basis. The services that we use don't run in the host VM. There's another VM, called the Guest VM, that runs within the host VM. Since we nevertheless have the VMRole, every guest VM holds a diff-store that will store the changes that are made to the virtual machine. The standard image is never modified. Each Host VM can contain several guest VMs.

The Windows Azure Series on Cloud Computing Journal

This article is part of the Windows Azure Series on Cloud Computing Journal. The Series was originally posted on Codefest.at, the official Blog of the Developer and Platform Group at Microsoft Austria. You can see the original Series here.