Server-side geo disaster recovery in Azure Event Grid

Event Grid supports automatic geo-disaster recovery of metadata for topics, domains, and event subscriptions. Event Grid automatically syncs your event-related infrastructure to a paired region. If an entire Azure region goes down, the events will begin to flow to the geo-paired region with no intervention from you.

Note that event data is not replicated to the paired region. Only the metadata is replicated. If a region supports availability zones, the event data is replicated across availability zones though.

Disaster recovery is measured with two metrics:

• Recovery Point Objective (RPO): the minutes or hours of data that may be lost.
• Recovery Time Objective (RTO): the minutes or hours the service may be down.

Event Grid’s automatic failover has different RPOs and RTOs for your metadata (topics, domains, event subscriptions.) and data (events). If you need different specification from the following ones, you can still implement your own client-side fail over using the topic health apis.

Recovery point objective (RPO)

• Metadata RPO: zero minutes. Anytime a resource is created in Event Grid, it's instantly replicated across regions. When a failover occurs, no metadata is lost.
• Data RPO: If your system is healthy and caught up on existing traffic at the time of regional failover, the RPO for events is about 5 minutes.

Recovery time objective (RTO)

• Metadata RTO: Though generally it happens much more quickly, within 60 minutes, Event Grid will begin to accept create/update/delete calls for topics and subscriptions.
• Data RTO: Like metadata, it generally happens much more quickly, however within 60 minutes, Event Grid will begin accepting new traffic after a regional failover.

Next steps

If you want to implement you own client-side failover logic, see # Build your own disaster recovery for custom topics in Event Grid