Azure's global infrastructure is a vast network, consisting of physical data centres and a high-speed network that spans the world.
Azure is divided into regions, which are like zones where data centres are located, and you choose a region for your online tasks.
Availability Zones (AZs) are backup data centres within each region, ensuring service reliability in case of issues.
Regions come in pairs, providing redundancy and disaster recovery capabilities, with the secondary region located at least 300 miles away.
Sovereign Regions, such as U.S. Government dedicated regions and Azure China, have special rules and purposes for government and legal compliance.
Throughout your journey with Microsoft Azure, you’ll hear and use terms like Regions, Availability Zones and more. Here is a breakdown before we start using the concepts soon!
What is the Azure global infrastructure?
The Azure global infrastructure is like a giant, worldwide network of super-powered computers that Microsoft uses to help people and businesses do all kinds of things on the internet. It's made up of two main parts:
Physical infrastructure: This part includes huge buildings called data centres, which are Azure's giant computer warehouses. They're filled with rows and rows of powerful computers, and they have special things like electricity, cooling, and fast internet connections. These data centres are spread all around the world, but they're also super secret - we're using their services every day, but we won't get to walk into data centres like a shop that's open for business! That's how Azure keeps them secure. Data centres are grouped into Azure Regions or Azure Availability Zones, which you'll learn about in just a second.
Network: A network is like the highways that connect different cities. In Azure's case, it's a network of high-speed connections and data pathways that link all the data centres together. This network ensures that data gets passed around the world quickly and securely.
Regions and Availability Zones
This worldwide network is divided into different regions. Each region is like a zone on the planet where these data centres are located. These regions are like different areas on a map where you can choose to do your online tasks. Whenever you create a resource in Azure, you'll often need to choose the region that your resource will live in.
Some services or features are only available in select regions, such as specific virtual machine or storage types!
There are also some global Azure services that don't need you to select a region. These services are not common, but examples include Azure Active Directory, Azure Traffic Manager, and Azure DNS (we'll learn about them in another day).
Within each region, there are what we call Availability Zones (AZs). These are like backup data centres nearby. So, if one has a problem, the others can keep working. It's a bit like having spare tires for your car - you don't want to be stuck if one goes flat!
Not all Azure Regions have Availability Zones
But the Regions that do have AZs have at least three separate AZs
Take a peek at the Australia East region!
To be extra safe, regions come in pairs. Pairs are like buddies that are far enough from each other to avoid problems like natural disasters or big power outages. In fact, they're at least 300 miles (480 kilometres) away! If one has trouble, the other can take over, like a friend helping you when you need it. The friend that comes to the rescue is called the secondary region.
Examples of region pairs in Azure are West US paired with East US, and South-East Asia paired with East Asia.
Because the pair of regions are directly connected and far enough apart to be isolated from regional disasters, you can use them to provide reliable services and data redundancy.
Data continues to reside within the same geography as its pair for tax and law purposes. Brazil South is unique because it's the only region paired with a region outside of its geography. Brazil South's secondary region is South Central US.
Most regions are paired in two directions, meaning they are backups for each other. However, some regions, such as West India and Brazil South, are paired only in one direction. For example, West India's secondary region is South India, but South India's secondary region is Central India.
There are also other advantages that come with using region pairs:
If an extensive Azure outage happens (i.e. across multiple regions), Azure prioritises restoring one region out of every region pair. This means applications hosted in region pairs can start back up as quickly as possible.
Azure updates are planned carefully. They happen in one region at a time between region pairs, so there's less chance of both regions not working and causing problems for apps.
Although region pairs are 300 miles apart, data still stays in the the same geography as its pair (except for Brazil South). This is really helpful for companies that need to keep their data in the same geography for tax and law reasons.
Some special regions are a bit different, they're called "Sovereign Regions." These are like secret rooms inside the big computer network. They have special rules because they are meant for certain government or legal purposes. There are two types of Sovereign Regions:
U.S. Government dedicated regions are completely private, so anyone that's not a government agency or partner cannot make anything in those regions! The data centres in these regions are operated by screened U.S. personnel and include additional compliance certifications.
Azure China has a very strict requirement and rules about how data is stored. Azure was the first foreign cloud service provider that met all of China's requirements. 21Vianet is a subset of Azure that manages all of this data and stays within China for compliance.