Switch over read replica to primary

Using the Azure portal:

1. Select the Azure Database for PostgreSQL flexible server for which you want to show its associated virtual endpoints.

2. In the resource menu, under the Settings section, select Replication.

   

3. Select the Promote icon to the side of the name of the endpoint of the read replica to which you want to switch over.

   

4. If the server doesn't have the virtual endpoints created, or if the read replica which you're trying to switch over to primary isn't the reader virtual endpoint's target server, an attempt to switch over a read replica to primary fails. That's what the warning displayed in the dialog reminds you.

   

5. In Replica server to promote, select Promote to primary server for Action. And select Planned or Forced for Data sync, depending on what suits your needs best. if you decide to use the Forced option, you have to mark the I understand that any data changes that have not been replicated from the primary server will be lost. The read replica lag time is the approximate period of data loss. checkbox to acknowledge the potential data loss. Finally, select Promote.

   

6. A notification informs you that the read replica is being switched over to primary.

   

7. When the process completes, a notification informs you that the read replica successfully switched over to primary.

   

You can switch over a read replica to become the new primary of your Azure PostgreSQL flexible server via the az postgres flexible-server replica promote command.

If you want to make sure that the read replica is first synchronized with all the changes existing on the primary server, before the switch over is initiated, then set --promote-option to planned:

az postgres flexible-server replica promote \
  --resource-group <resource_group> \
  --name <server> \
  --promote-mode SwitchOver \
  --promote-option Planned

If you prefer the switch over to complete faster, and can assume that the changes which are already committed on the primary server but not yet synchronized to the read replica will be lost, then set --promote-option to forced:

az postgres flexible-server replica promote \
  --resource-group <resource_group> \
  --name <server> \
  --promote-mode SwitchOver \
  --promote-option Forced