The company is implementing XenDesktop globally for desktop virtualization.

Installing a minimum of two Delivery Controllers in every datacenter is a fundamental best practice for achieving local high availability. This redundancy ensures that if one controller fails within a specific datacenter, the other controller can seamlessly take over its functions, maintaining continuous service for users.

While deploying three controllers offers N+1 redundancy and increased capacity, two controllers per datacenter is the standard minimum recommendation for high availability, and the specific locations are not a general rule for 'each datacenter'.

Three controllers in specific locations (Hong Kong and New York) are not the general best practice for providing high availability in 'each datacenter' and may exceed the minimum requirement.

Deploying three controllers might be for capacity beyond just HA, and the specific locations like Oslo are not a general best practice for 'each datacenter' in a global context.