Service Bus
The legacy Geo-DR feature — still what most existing docs and architectures reference — replicates namespace metadata only, not messages. The newer Geo-Replication feature (Premium) replicates message data too, but promotion is always customer-triggered.
Standard tier, or Premium without zone redundancy
Single messaging unit / namespace, no zone spread.
- Replication
- None
- RPO
- 0 for platform-level node failure
- RTO
- Minutes — platform self-heals
- Failover trigger
- Automatic
Premium tier with Availability Zones enabled
Broker state synchronously replicated across zones in supported regions — no message loss on zone failure.
- Replication
- Synchronous
- RPO
- 0
- RTO
- Seconds — automatic
- Failover trigger
- Automatic
Geo-Replication (Premium — recommended over legacy Geo-DR)
Replicates both metadata and message data/state to one secondary region, in synchronous or asynchronous mode. Promotion is always customer-triggered — Azure never fails over on its own.
- Replication
- Asynchronous
- RPO
- 0 in synchronous mode (at a latency/availability cost); otherwise bounded by your configured max replication lag in async mode
- RTO
- Typically a couple of minutes once triggered — but only ever customer-triggered
- Failover trigger
- Manual (customer-triggered)
Requires Premium tier. Cannot be combined with the legacy Geo-DR feature on the same namespace.
Gotchas
Legacy Geo-DR does not replicate messages — at all
Geo-Disaster Recovery (the feature most existing Service Bus architectures reference) replicates namespace metadata — queues, topics, subscriptions, configuration — only. Anything sitting in a queue, topic subscription, or dead-letter queue is lost on failover. If your DR plan relies on Geo-DR for message-level RPO, it doesn't have one.
The message-replicating alternative still needs a human to promote it
Geo-Replication (the newer, recommended feature) does replicate message data and state, and can even run in synchronous mode for RPO 0 — but promotion from primary to secondary is always customer-initiated. Microsoft's docs state plainly: 'Azure never triggers a promotion.'
Both DR features are Premium-only
Standard tier Service Bus has no cross-region replication story at all — DR means rebuilding a namespace and re-pointing clients from scratch.