What is Microsoft Azure Availability Zone?

1. Pre-requisite Knowledge –

Before we start with the understanding of what is Microsoft Azure Availability Zone, we should know –

• Basic knowledge of cloud computing and its services
• Basic knowledge of Microsoft Azure
• Basic knowledge of Virtual Machine

2. Background –

In this article, we will explore what is Microsoft Azure Availability Zone. Before we look into it, let’s understand ‘what is availability zone?’ -

• Cloud provider has data centers over all the world within different regions.
• An availability zone is an isolated location within the region from which cloud provider provides service to the cloud users.
• Every region can have one or multiple zones and they are isolated from each other.
• Each zone can have one or more multiple data centers with independent power, cooling, and networking.
• This is also needed for critical workloads with compliance, decrease latency and data authority requirements.
• Admin can move resources of applications within the zones in case of an outage.

3. Introduction of Microsoft Azure Availability Zones –

• Microsoft Azure provides availability zones for high availability applications that protect data from data center failures.
  
  

Image Source – Microsoft Docs

• The failure can be because of major two reasons –
  • Fault domain - refers to unexpected hardware failure.
  • Update domain - refers to predetermined software updates on Azure.

• We can implement the zone redundant applications and data across the zones.
• To make the application highly available and protect it from disaster recovery then replicate the components of the application with other zones.
• We can use Azure Availability Set feature which is a logical grouping capability for isolating Virtual Machines from each other when they are deployed in the Azure data center. Refer my article on availability set here.
• Azure availability zone has two categories –
  1. Zonal services – pin the resource to a specific zone (for example, virtual machines, managed disks, IP addresses)
  2. Zone-redundant services – platform replicates automatically across zones (for example, zone-redundant storage, SQL Database).
• There is no additional cost for availability zone VMs.
• Microsoft claims 99.99% availability if we deploy two or more virtual machines across two or more availability zones within an Azure region.
• Following regions are supported for availability zones in Azure cloud as of now –
  1. Central US
  2. East US
  3. East US 2
  4. West US 2
  5. France Central
  6. North Europe
  7. UK South
  8. West Europe
  9. Japan East
  10. Southeast Asia

4. Reference Links –

• https://docs.microsoft.com/en-us/azure/availability-zones/az-overview
• https://gist.github.com/JonCole/92c669ea482bbb7996f6428fb6c3eb97#file-redisazgettingstarted-md
• https://searchaws.techtarget.com/definition/availability-zones
• https://blog.rackspace.com/aws-101-regions-availability-zones

Conclusion - In this article, we have learned the overview of Microsoft Azure Availability Zone.