How to create and manage read replicas in Azure Database for MySQL using the Azure portal
APPLIES TO: 
Azure Database for MySQL - Single Server
Important
Azure Database for MySQL single server is on the retirement path. We strongly recommend that you upgrade to Azure Database for MySQL flexible server. For more information about migrating to Azure Database for MySQL flexible server, see What's happening to Azure Database for MySQL Single Server?
In this article, you will learn how to create and manage read replicas in the Azure Database for MySQL service using the Azure portal.
Prerequisites
- An Azure Database for MySQL server that will be used as the source server.
Important
The read replica feature is only available for Azure Database for MySQL servers in the General Purpose or Memory Optimized pricing tiers. Ensure the source server is in one of these pricing tiers.
Create a read replica
Important
If your source server has no existing replica servers, source server might need a restart to prepare itself for replication depending upon the storage used (v1/v2). Please consider server restart and perform this operation during off-peak hours. See Source Server restart for more details.
If GTID is enabled on a primary server (gtid_mode = ON), newly created replicas will also have GTID enabled and use GTID based replication. To learn more refer to Global transaction identifier (GTID)
A read replica server can be created using the following steps:
Sign in to the Azure portal.
Select the existing Azure Database for MySQL server that you want to use as a master. This action opens the Overview page.
Select Replication from the menu, under SETTINGS.
Select Add Replica.
Enter a name for the replica server, such as mydemoreplicaserver.
Select the location for the replica server. The default location is the same as the source server's.
Note
To learn more about which regions you can create a replica in, visit the read replica concepts article.
Select OK to confirm creation of the replica.
Note
Read replicas are created with the same server configuration as the master. The replica server configuration can be changed after it has been created. The replica server is always created in the same resource group and same subscription as the source server. If you want to create a replica server to a different resource group or different subscription, you can move the replica server after creation. It is recommended that the replica server's configuration should be kept at equal or greater values than the source to ensure the replica is able to keep up with the master.
Once the replica server has been created, it can be viewed from the Replication blade.
Stop replication to a replica server
Important
Stopping replication to a server is irreversible. Once replication has stopped between a source and replica, it cannot be undone. The replica server then becomes a standalone server and now supports both read and writes. This server cannot be made into a replica again.
To stop replication between a source and a replica server from the Azure portal, use the following steps:
In the Azure portal, select your source Azure Database for MySQL server.
Select Replication from the menu, under SETTINGS.
Select the replica server you wish to stop replication for.
Select Stop Replication.
Confirm you want to stop replication by clicking OK.
Delete a replica server
To delete a read replica server from the Azure portal, use the following steps:
In the Azure portal, select your source Azure Database for MySQL server.
Select Replication from the menu, under SETTINGS.
Select the replica server you wish to delete.
Select Delete Replica.
Type the name of the replica and click Delete to confirm deletion of the replica.
Delete a source server
Important
Deleting a source server stops replication to all replica servers and deletes the source server itself. Replica servers become standalone servers that now support both read and writes.
To delete a source server from the Azure portal, use the following steps:
In the Azure portal, select your source Azure Database for MySQL server.
From the Overview, select Delete.
Type the name of the source server and click Delete to confirm deletion of the source server.
Monitor replication
In the Azure portal, select the replica Azure Database for MySQL server you want to monitor.
Under the Monitoring section of the sidebar, select Metrics:
Select Replication lag in seconds from the dropdown list of available metrics.
Select the time range you wish to view. For example, you can select a 30 minute time range.
View the replication lag for the selected time range. With the time range of 30 minutes, the example displays the last 30 minutes.
Next steps
- Learn more about read replicas