We’re pleased to announce the availability of forced failover for Azure Database for MySQL - Flexible Server in all zone redundant regions. This functionality enables you to manually force a failover to test functionality with your application scenarios, which can help to prepare you in case of any outages.
When you trigger a failover, the standby replica is activated to become the primary server with the same database server name by updating the DNS record. While client connections are disconnected, you can automatically reconnect them to resume operations if you have implemented retry-logic, which is recommended for cloud native applications.
Before the forced failover begins, a pop-up window displays the estimated time for completion of the operation by factoring the recency of the last checkpoint and the current transactions running on the primary server.
Forcing a failover in Azure Database for MySQL – Flexible Server using the Azure Portal
To force a failover from your primary server to a standby instance of Flexible Server, perform the following steps:
- In the Azure portal, select an existing instance of Azure Database for MySQL Flexible Server that has high availability enabled.
- On the page associated with the selected server, under Settings, select High availability.
- On the High availability page, make a note of the values associated with Primary availability zone and Standby availability zone.
We’ll compare these numbers to similar values we get after the failover completes.
- To initiate the manual failover procedure, select Forced Failover.
A pop-up window displays the estimated failover time, estimated based on the current workload on the primary server and the recency of the last checkpoint.
- Read the message, and then select OK.
An "Initiating the failover process..." notification appears. Then, after failover to the standby server completes successfully, second notification appears.
- Compare the new Primary availability zone and the Standby availability zone to the values before the failover.
Notice that the value of the Primary availability zone is now the original value of the Standby availability zone.
As you can see, the forced failover process is easy to accomplish and use in your own environment. Azure Database for MySQL Flexible Server also offers automatic failover using zone redundant high availability. For more information, see High availability concepts in Azure Database for MySQL Flexible Server.