Azure provides high availability, disaster recovery, and backup solutions that can enable your applications to meet business availability requirements and recovery objectives. We continue to build upon our portfolio of resilient services by bringing zonal capabilities for improved business continuity and disaster recovery with Azure Site Recovery. Azure Site Recovery replicates workloads running on physical and virtual machines (VMs) from a primary site to a secondary location. When an outage occurs at your primary site, you failover to a secondary location, and access apps from there. After the primary location is running again, you can fail back to it. Azure Site Recovery helps ensure business continuity by keeping business apps and workloads running during outages.  

With the zonal disaster recovery capability, we are making it possible to replicate and orchestrate the failover of applications in Azure across Azure Availability Zones within a given region. Zone to Zone disaster recovery options with Azure Site Recovery is on its way to being available in all regions with Azure Availability Zones (AZs). Availability Zones, fault-isolated locations within an Azure region, provide redundant power, cooling, and networking, allowing customers to run mission-critical applications with higher availability and fault tolerance to datacenter failures. Azure Availability Zones will be available in every country Microsoft Azure publicly operates in by the end of 2021. 

While Availability Zones are traditionally used by customers for high availability, they can also be leveraged for Disaster Recovery under specific scenarios. The capability adds disaster recovery options for scenarios that may require maintaining data residency and local compliance, reducing the complexity of configuring a DR strategy in a secondary region, and improving the recovery point objective (RPO). 

Adhering to local compliance and data residency

To support customers’ unique compliance and data residency needs, Azure offers regions within geographies that provide a distinct boundary for data residency and compliance. Zone to Zone recovery can be leveraged by customers that prefer to keep applications within a particular legal jurisdiction since your applications and data do not cross-national boundaries. Azure provides a wide portfolio of more than 90 compliance offerings to support streamlined compliance and protect data with the most comprehensive compliance coverage.

Reducing the complexity of DR in a secondary region, latency, and RPO

Many Azure regions are designed to provide traditional disaster recovery, with a distinct region that has a large degree of separation from the other location. For some customers enabling this type of DR requires recreation of complicated networking infrastructure and increased cost and operational complexity. Zone to Zone disaster recovery reduces complexity as it leverages redundant networking concepts across Availability Zones making configuration much simpler. 

Since Availability Zones are designed to support synchronous replication while optimizing physical separation to offer protection and isolation from localized failures, this also means the data traverse shorter distances when compared with region to region DR so customers may see lower latency and consequently lower RPO by leveraging zonal DR. 

“When Availability Zones for Azure were being made available, we were in the middle of moving our production workloads to cloud from on-premises datacenters. At that time, we made a bold decision to start distributing all of our IaaS instances across different zones to maximize benefits of redundancy and minimize impact of single datacenter failures on business-facing applications. We looked at recently announced Zone to Zone replication as an enhancement of our DR capability and implemented it in production. The call was quite easy, given that we had prior positive experience with ASR and we’d simply change the datacenter to which we replicate. A couple of drills for different applications were conducted in non-production environments with great success—we were able to restore the protected VMs in about 10 minutes. By failing over to the same region/VNET, we didn’t need to create dedicated test networks which greatly reduces administrative overhead. I really liked the fact that Azure took care of almost the entire failover process end-to-end with provisioning new VM, attaching the disks, and even swapping the IP so that other applications could quickly reconnect to the “new” instance.” – Patryk Wolski, Senior Manager – Infrastructure Lead at Accenture.

Architecting for zonal resilience and disaster recovery

Beyond providing the right capabilities in the right regions, we are also committed to providing guidance and proven practices to help our customers and partners take advantage of these capabilities. We recently launched the Azure Well-Architected Framework—a set of guiding tenets that can be used to improve the quality of a workload. Reliability is one of the five pillars of architectural excellence alongside Cost Optimization, Operational Excellence, Performance Efficiency, and Security. If you already have a workload running in Azure and would like to assess your alignment to best practices in one or more of these areas, try the Azure Well-Architected Review.

We continue to hear from customers the importance of having a resiliency strategy that supports a wide range of scenarios. We maintain detailed guidance on designing reliable applications, including best practices for architectural design, monitoring application health, and responding to failures and disasters. We invite customers to learn more about using Zone to Zone recovery to  strengthen their resiliency posture.