How would you design a highly available messaging solution using Azure Service Bus?

Design a highly available Azure Service Bus solution by using geo-redundant architecture, appropriate messaging patterns, resilient clients, and operational safeguards such as retries, dead-letter handling, monitoring, and capacity planning. The core design usually combines Azure Service Bus Premium namespaces, zone redundancy, paired regions with failover strategies, and application-level idempotency because messaging guarantees are typically at-least-once rather than exactly-once. The system should treat regional outages, duplicate messages, poison messages, and dependency failures as expected scenarios.

A highly available Azure Service Bus design starts by identifying the failure domains that must be tolerated:

The design approach depends on the required recovery objectives: