Azure Availability Zones Help Resilience, But Charges Coming

• Azure Availability Zones improve Azure deployment fault tolerance within an Azure region.
• Availability Zones are becoming available in more Azure regions and are offered in every country that has a region.
• Certain data transfer across Availability Zones will incur costs starting in July 2023, which could introduce new charges for existing deployments.

Azure Availability Zones (AZs) are isolated portions of an Azure region that can improve application availability for certain types of local failures.

What Are Availability Zones?

AZs allow certain applications and data to be deployed in fault-isolated physical locations within an Azure region. An Azure region is a geographical location with a data center or multiple collocated data centers.

Each AZ uses separate power, network, and cooling systems so that if these systems fail in one AZ, the other AZs are not necessarily affected. Customers can deploy redundant copies of a resource (such as a VM) in separate AZs, enabling the resource to survive the loss of an AZ, improving fault tolerance for an Azure solution.