How to create and manage read replicas in Azure Database for PostgreSQL using PowerShell

APPLIES TO: Azure Database for PostgreSQL - Single Server

Important

Azure Database for PostgreSQL - Single Server is on the retirement path. We strongly recommend that you upgrade to Azure Database for PostgreSQL - Flexible Server. For more information about migrating to Azure Database for PostgreSQL - Flexible Server, see What's happening to Azure Database for PostgreSQL Single Server?.

In this article, you learn how to create and manage read replicas in the Azure Database for PostgreSQL service using PowerShell. To learn more about read replicas, see the overview.

Azure PowerShell

You can create and manage read replicas using PowerShell.

Prerequisites

To complete this how-to guide, you need:

• The Az PowerShell module installed locally or Azure Cloud Shell in the browser
• An Azure Database for PostgreSQL server

Important

While the Az.PostgreSql PowerShell module is in preview, you must install it separately from the Az PowerShell module using the following command: Install-Module -Name Az.PostgreSql -AllowPrerelease. Once the Az.PostgreSql PowerShell module is generally available, it becomes part of future Az PowerShell module releases and available natively from within Azure Cloud Shell.

If you choose to use PowerShell locally, connect to your Azure account using the Connect-AzAccount cmdlet.

Azure Cloud Shell

Azure hosts Azure Cloud Shell, an interactive shell environment that you can use through your browser. You can use either Bash or PowerShell with Cloud Shell to work with Azure services. You can use the Cloud Shell preinstalled commands to run the code in this article, without having to install anything on your local environment.

To start Azure Cloud Shell:

Option	Example/Link
Select Try It in the upper-right corner of a code or command block. Selecting Try It doesn't automatically copy the code or command to Cloud Shell.
Go to https://shell.azure.com, or select the Launch Cloud Shell button to open Cloud Shell in your browser.
Select the Cloud Shell button on the menu bar at the upper right in the Azure portal.

To use Azure Cloud Shell:

1. Start Cloud Shell.

2. Select the Copy button on a code block (or command block) to copy the code or command.

3. Paste the code or command into the Cloud Shell session by selecting Ctrl+Shift+V on Windows and Linux, or by selecting Cmd+Shift+V on macOS.

4. Select Enter to run the code or command.

Important

The read replica feature is only available for Azure Database for PostgreSQL servers in the General Purpose or Memory Optimized pricing tiers. Ensure the primary server is in one of these pricing tiers.

Create a read replica

A read replica server can be created using the following command:

Get-AzPostgreSqlServer -Name mydemoserver -ResourceGroupName myresourcegroup |
  New-AzPostgreSqlReplica -Name mydemoreplicaserver -ResourceGroupName myresourcegroup

The New-AzPostgreSqlReplica command requires the following parameters:

Setting	Example value	Description
ResourceGroupName	myresourcegroup	The resource group where the replica server is created.
Name	mydemoreplicaserver	The name of the new replica server that is created.

To create a cross region read replica, use the Location parameter. The following example creates a replica in the West US region.

Get-AzPostgreSqlServer -Name mrdemoserver -ResourceGroupName myresourcegroup |
  New-AzPostgreSqlReplica -Name mydemoreplicaserver -ResourceGroupName myresourcegroup -Location westus

To learn more about which regions you can create a replica in, visit the read replica concepts article.

By default, read replicas are created with the same server configuration as the primary unless the Sku parameter is specified.

Note

It is recommended that the replica server's configuration should be kept at equal or greater values than the primary to ensure the replica is able to keep up with the primary.

List replicas for a primary server

To view all replicas for a given primary server, run the following command:

Get-AzPostgreSQLReplica -ResourceGroupName myresourcegroup -ServerName mydemoserver

The Get-AzPostgreSQLReplica command requires the following parameters:

Setting	Example value	Description
ResourceGroupName	myresourcegroup	The resource group where the replica server will be created to.
ServerName	mydemoserver	The name or ID of the primary server.

Stop a replica server

Stopping a read replica server promotes the read replica to be an independent server. It can be done by running the Update-AzPostgreSqlServer cmdlet and by setting the ReplicationRole value to None.

Update-AzPostgreSqlServer -Name mydemoreplicaserver -ResourceGroupName myresourcegroup -ReplicationRole None

Delete a replica server

Deleting a read replica server can be done by running the Remove-AzPostgreSqlServer cmdlet.

Remove-AzPostgreSqlServer -Name mydemoreplicaserver -ResourceGroupName myresourcegroup

Delete a primary server

Important

Deleting a primary server stops replication to all replica servers and deletes the primary server itself. Replica servers become standalone servers that now support both read and writes.

To delete a primary server, you can run the Remove-AzPostgreSqlServer cmdlet.

Remove-AzPostgreSqlServer -Name mydemoserver -ResourceGroupName myresourcegroup

Next steps

Restart Azure Database for PostgreSQL server using PowerShell