Configure high availability for Azure Database for PostgreSQL

1. In the Azure portal, select your Azure Database for PostgreSQL flexible server instance.

2. On the left menu, in the Settings section, select High availability.

The Zonal Resiliency option controls whether your server is protected across availability zones. You have two choices:

• Enabled – When you select this option, Azure tries to create the standby server in a different availability zone than the primary. This option gives you the best protection against zone-level failures.
• Disabled – High availability isn't configured.

If you enable zonal resiliency but your region lacks capacity for a zone-redundant setup, an extra checkbox appears under the Enabled option. Selecting this checkbox allows the standby server to be created in the same zone as the primary server. When zonal capacity becomes available, Azure notifies you. At that point, you can use either PITR or read replicas to migrate workloads to a zone-redundant HA configuration for maximum resiliency. For more information, see the Limitations and Considerations section.

1. If you didn't enable Zonal Resiliency, select the Enabled option.

   

2. When you select the Enabled option, the Zone redundant option is applied by default for regions that support availability zones. This configuration protects against zonal failures.

   

3. If the region doesn't have zonal capacity, to make sure that high availability (HA) gets enabled in your preferred region, select the checkbox under the enabled option to allow creating HA with Same-Zone mode of the region. It automatically migrates your workloads to Zone-Redundant HA once zonal capacity becomes available:

   

4. When you're done configuring the settings, select Save to apply the changes.

5. A dialog shows the cost increase associated with the deployment of the standby server. If you decide to proceed, select Enable high availability.

   

6. A deployment starts. When it finishes, a notification shows that you successfully enabled high availability.

   

You can enable high availability in an existing server by using the az postgres flexible-server update command.

To enable high availability with the standby server in the same zone as the primary server, use this command:

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability SameZone

To enable high availability with the standby server in a different zone from the primary server's zone, and if you want the zone to be automatically selected, use this command:

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability ZoneRedundant

Optionally, you can select the availability zone in which to deploy the standby server. Use this command:

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability ZoneRedundant \
  --standby-zone <standby_zone>

If you enable high availability with zone redundancy, and the zone you specify for standby matches the zone of the primary, you get this error:

Your server is in availability zone <server>. The zone of the server cannot be same as the standby zone.

If you enable high availability with zone redundancy, and the zone you specify for standby isn't available in that region, you get this error:

Code: InvalidParameterValue
Message: Invalid value given for parameter StandbyAvailabilityZone,availabilityZone. Specify a valid parameter value.

If you enable high availability with zone redundancy, and the region doesn't have multiple availability zones, you get this error:

This region is single availability zone. Zone redundant high availability is not supported in a single availability zone region.

If you enable high availability in one mode, and then try to enable it again by specifying a different mode, you get this error:

Code: InvalidParameterValue
Message: Invalid value given for parameter Cannot switch Properties.HighAvailability.Mode directly from SameZone to ZoneRedundant. Please disable HA and then enable HA.. Specify a valid parameter value.

The --zonal-resiliency parameter helps you create a standby server in a different availability zone than primary and protects against zone‑level failures. It accepts two values:

• Enabled – When you select this option, Azure tries to create the standby server in a different availability zone than the primary. This option gives you the best protection against zone-level failures.
• Disabled – High availability isn't configured.

To ensure your server is configured for high availability, enable the --allow-same-zone parameter. In regions without multiple availability zones, this option allows the standby server to be created in the same zone as the primary. When zonal capacity becomes available, Azure notifies you. At that point, you can use PITR or read replicas to migrate to a zone‑redundant HA configuration for maximum resiliency. For more information, refer to the Limitations and Considerations section.

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --zonal-resiliency enabled
  --allow-same-zone

1. In the Azure portal, select your Azure Database for PostgreSQL flexible server instance.

2. On the left menu, in the Settings section, select High availability.

3. If high availability is enabled, the Enabled radio button for Zonal Resiliency is already selected. Also, High availability mode is set to the configured mode, and the High availability status value is typically Healthy.

   

4. Select the Disabled radio button to disable high availability.

   

5. Select Save to apply the changes.

6. A dialog shows the cost reduction associated with the removal of the standby server. If you decide to proceed, select Disable high availability.

   

7. A deployment starts. When it finishes, a notification shows that you successfully disabled high availability.

   

You can disable high availability in an existing server by using the az postgres flexible-server update command:

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability Disabled

To disable high availability, run the same command with --zonal-resiliency set to disabled. The previous --high-availability parameter is deprecated and now triggers this warning: "Argument '--high-availability' has been deprecated and will be removed in next breaking change release(2.86.0) scheduled for May 2026. Use '--zonal-resiliency' instead."

az postgres flexible-server update \
  --resource-group <resource_group> \
  --name <server> \
  --zonal-resiliency Disabled

1. In the Azure portal, during provisioning of a new Azure Database for PostgreSQL flexible server instance, go to the Business Critical (High availability) section. Select the Enabled option in the Zonal Resiliency section.

   • By default, the server tries to create the standby server in a different availability zone with Zone-Redundant HA mode for maximum zonal resiliency.

   

   • If zonal capacity isn't available, select the Allow standby in same zone if zonal resiliency fails checkbox as a fallback. If you don't select this option, you can't proceed to the next step in the create workflow. This check ensures high availability remains enabled. When zonal capacity becomes available, Azure notifies you. You can then use PITR or read replicas to migrate workloads to a zone-redundant HA configuration for maximum resiliency.

     

   • After you select the checkbox, proceed to the Authentication section in the create workflow.

     

2. Select a specific zone for the primary server by setting Availability zone to any value other than No preference.

   

You can enable high availability while provisioning a new server by using the az postgres flexible-server create command.

To deploy the primary server with a standby server in the same zone, and let the service choose the zone for you, use this command:

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability SameZone ...

To deploy the primary server with a standby server in the same zone, and explicitly choose the zone, use this command:

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability SameZone \
  --zone <zone> ...

If the specified availability zone isn't supported in the selected region, you get this error:

Code: AvailabilityZoneNotAvailable
Message: Specified availability zone is not supported in this region. Please choose a different availability zone.

To deploy the primary server with a standby server in a different zone, and let the service choose both zones for you, use this command:

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability ZoneRedundant ...

To deploy the primary server with a standby server in a different zone, and to specify the zone for the primary but let the service choose the zone for the standby, use this command:

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability ZoneRedundant \
  --zone <zone> ...

To deploy the primary server with a standby server in a different zone, and to specify the zone for the primary and the standby, use this command:

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --high-availability ZoneRedundant \
  --zone <zone> \
  --standby-zone <standby_zone>...

If you choose zone-redundant high availability, and specify the same value for the zones of the primary and standby servers, you get this error:

Your server is in availability zone <zone>. The zone of the server cannot be same as the standby zone.

If the high-availability mode that you select is zone redundant, and the region doesn't have multiple availability zones, you get this error:

This region is single availability zone. Zone redundant high availability is not supported in a single availability zone region.

Use the --zonal-resiliency parameter when creating an Azure Database for PostgreSQL flexible server instance. This ensures the standby server is provisioned in a different availability zone than the primary, improving protection against zone‑level failures.

If the region doesn't currently support multiple availability zones, add the --allow-same-zone parameter. This parameter acts as a fallback: if Azure can't create the standby in another zone, it creates the standby in the same zone as the primary so that high availability is still enabled in your chosen region. When zonal capacity later becomes available, Azure notifies you. You can then use PITR or a read replica to move your workloads to a zone‑redundant HA configuration for improved resiliency.

The --zonal-resiliency parameter accepts these values:

• Enabled – When you select this option, Azure tries to create the standby server in a different availability zone than the primary. This option gives you the best protection against zone-level failures.
• Disabled – High availability isn't configured.

az postgres flexible-server create \
  --resource-group <resource_group> \
  --name <server> \
  --zonal-resiliency enabled \
  --allow-same-zone

1. In the Azure portal, select your Azure Database for PostgreSQL flexible server instance that has high availability enabled.

2. On the left menu, in the Settings section, select High availability.

3. If the high-availability mode is set to Zone redundant, note the values assigned to Primary availability zone and Standby availability zone. Reverse these values after the failover operation finishes.

4. Select Forced failover to start the manual failover procedure. A dialog informs you of the expected downtime until the failover finishes. If you decide to proceed, select Initiate forced failover.

   

5. A notification appears and mentions that a failover is in progress.

   

6. After the failover to the standby server completes, a notification informs you of the completion.

   

7. If the high-availability mode is configured as Zone redundant, confirm that the values of Primary availability zone and Standby availability zone are now reversed.

You can enable high availability while provisioning a new server by using the az postgres flexible-server restart command.

To initiate a forced failover, use this command:

az postgres flexible-server restart \
  --resource-group <resource_group> \
  --name <server> \
  --failover Forced

If you try to force the failover of an Azure Database for PostgreSQL flexible server instance that doesn't have high availability enabled, you get this error:

Failing over can only be triggered for zone redundant or same zone servers.

If you try to force the failover of an Azure Database for PostgreSQL flexible server instance that has high availability enabled but isn't ready to initiate the failover operation, you get this error:

Code: OperationFailed
Message: Operation HandleWalServiceFailureManagementOperation failed, because server <server> not in active state.

1. In the Azure portal, select your Azure Database for PostgreSQL flexible server instance that has high availability enabled.

2. On the left menu, in the Settings section, select High availability.

3. If the high-availability mode is set to Zone redundant, note the values assigned to Primary availability zone and Standby availability zone. Reverse these values after the failover operation finishes.

4. Select Planned failover to start the manual failover procedure. A dialog informs you of the expected downtime until the failover finishes. If you decide to proceed, select Initiate planned failover.

   

5. A notification appears and mentions that failover is in progress.

   

6. After the failover to the standby server completes, a notification informs you of the completion.

   

7. If the high-availability mode is configured as Zone redundant, confirm that the values of Primary availability zone and Standby availability zone are now reversed.

You can enable high availability while provisioning a new server by using the az postgres flexible-server restart command.

To initiate a planned failover, use the following command:

az postgres flexible-server restart \
  --resource-group <resource_group> \
  --name <server> \
  --failover Planned

If you try to initiate the planned failover of an Azure Database for PostgreSQL flexible server instance that doesn't have high availability enabled, you get the following error:

Failing over can only be triggered for zone redundant or same zone servers.

If you try to initiate the planned failover of an Azure Database for PostgreSQL flexible server instance that has high availability enabled but isn't ready for the failover operation, you get the following error:

Code: OperationFailed
Message: Operation HandleWalServiceFailureManagementOperation failed, because server <server> not in active state.