Azure operates in multiple geographies around the world. An Azure geography is a defined area of the world that contains at least one Azure Region. An Azure region is an area within a geography, containing one or more datacenters.
To ensure Business continuity and disaster recovery (BCDR) each Azure region is paired with another region within the same geography, together making a regional pair.
Figure 1 – Azure regional pair diagram
|LMS365 Geography||Paired regions|
|Asia Pacific||Japan East||Japan West|
|Australasia||Australia East||Australia Southeast|
|Canada||Canada Central||Canada East|
|Germany||Central Germany||Northeast Germany|
|Europe||North Europe (Ireland)||West Europe (Netherlands)|
|North America||Central US||East US 2|
|UK||UK South||UK West|
|US Government||US Gov Virginia||US Gov Texas|
An example of paired regions
Figure 2 below shows a hypothetical application which uses the regional pair for disaster recovery. The green numbers highlight the cross-region activities of three Azure services (Azure compute, storage, and database) and how they are configured to replicate across regions. The unique benefits of deploying across paired regions are highlighted by the orange numbers.
Figure 2 – Hypothetical Azure regional pair
More Information from: https://docs.microsoft.com/en-us/azure/best-practices-availability-paired-regions