Azure Postgresql Managed flexible server: Question about zonal high availability behaviour

Question

What happens if the availability zone hosting the standby server fails, but the primary zone remains healthy?

Specifically:

• Does the primary continue operating normally?
• Is high availability temporarily degraded?
• Will Azure automatically recreate the standby in another zone?
• Is there any impact on performance or data durability during this period?

Answer 1

Hi ruben fernandez martinez

Greeting!!

If the availability zone hosting the standby server fails but the primary zone remains healthy, your system should continue operating normally—though with reduced high availability until the standby is restored.

Here’s what typically happens in this scenario:

No Failover Triggered: Since the primary server is still up and running, there’s no need for a failover. Applications continue to connect to the primary as usual.

High Availability Degraded: The system enters a degraded HA state. You temporarily lose the redundancy that protects against primary zone failure.

Automatic Standby Reprovisioning: In many managed services like Azure SQL Hyperscale or PostgreSQL Flexible Server, the platform will attempt to recreate the standby replica in another healthy zone automatically.

• Monitoring & Alerts: Azure Monitor or your own observability tools should alert you to the degraded HA state so you can track recovery progress. Please refer the Microsoft document link for more help. https://learn.microsoft.com/en-us/azure/reliability/reliability-postgresql-flexible-server I hope this helps, please let me know if you need any more assistant, we are happy to help