Cloud computing is known for high-availability and low latency, so cloud computing providers are made available solution for mission-critical applications which is not possible to handle all thing from one data-center to all over world that's why cloud computing providers set up the datacenter in different regions, and datacenter is the setup of computing machines and networking. More than one datacenter equipped with independent power, cooling, and networking, which is called the Availability Zone.
For a current update about Regions and Availability Zones click here
Availability Zones are the combination of the data-center where data -centers are equipped with independent power, cooling, and networking, which protects your applications from datacenter failure.
Why needed Availability Zones in Microsoft Azure.
1- If you select any region to set up your environment to ensure resiliency, Azure provides three separates zones in all enables regions.
2- The physical separation of Availability Zones within a region protects applications and data from datacenter failure.
3- Zone-redundant services replicate your applications and data across Availability Zones to protect from single-points-of-failure.
4- With Availability Zones, Azure offers industry best 99.99% VM uptime SLA.
An Availability Zone in an Azure region is a combination of a fault domain and an update domain. For example, if you create three or more VMs across three zones in an Azure region, your VMs are effectively distributed across three fault domains and three update domains. The Azure platform recognizes this distribution across update domains to make sure that VMs in different zones are not updated at the same time.
Regions that support Availability Zones
1. Central US
2. East US 2 (Preview)
3. France Central
4. North Europe
5. Southeast Asia
6. West Europe
7. West US 2
Services that support Availability Zones
The Azure services that support Availability Zones are:
1. Linux Virtual Machines
2. Windows Virtual Machines
3. Virtual Machine Scale Sets
4. Managed Disks
5. Load Balancer
6. Public IP address
7. Zone-redundant storage
8. SQL Database
9. Event Hubs
10. Service Bus
11. VPN Gateway
12. ExpressRoute
13. Application Gateway
For a current update about Regions and Availability Zones click here