Scaling Azure Database for MySQL flexible server

Question

Hi,

We are in the process of upscaling our MySQL Flexible Servers. Currently, we have a master and a replica setup. I had a few queries regarding the upgrade process:

1. Will the replica be automatically upgraded when we upscale the master server? If not, what is the correct way to upgrade the replica?
2. What kind of downtime can we expect when upgrading the compute size of the master server?

Answer 1

Hi Vishesh

Thanks for using the Q&A platform.

Regarding your first question, the answer is NO, replicas are not automatically scaled when you upscale the primary server. You will need to manually scale the replica to match the compute configuration of the primary server.

On your second question, scaling compute (vCores/memory) for Flexible Server is a resizing operation, and yes, it involves a short downtime. What happens is that Azure will restart the MySQL instance during compute scaling. The duration usually depends on the size of the server, active connections, and data volume.

Kindly find documentation for more insight: https://learn.microsoft.com/en-us/azure/mysql/flexible-server/concepts-maintenance?utm_source=chatgpt.com#near-zero-downtime-maintenance-preview

You can mark it 'Accept Answer' and 'Upvote' if this helped you

Regards,

Obinna.

Answer 2

Hello Vishesh

I understood that you want to know more about the MySQL flexible server and its replica.

Kindly please refer the below information,

Will the replica be automatically upgraded when we upscale the master server? If not, what is the correct way to upgrade the replica?

Replicas don't automatically scale alongside the primary server during an upscaling process. You'll need to manually adjust the replica's compute configuration. It is recommended that the replica server's configuration should be kept at equal or greater values than the source to ensure the replica can keep up with the source.

Please refer the below document for better understanding,
https://learn.microsoft.com/en-us/azure/mysql/flexible-server/how-to-read-replicas-portal

What kind of downtime can we expect when upgrading the compute size of the master server?

Yes, there will be a minimal downtime, as the Azure will restart the server during the scaling process. Server downtime can vary depending on factors like the size, connections which are active and the complexity of the schema.

Please refer the below document for better understanding,
https://learn.microsoft.com/en-us/azure/mysql/flexible-server/concepts-maintenance?utm_source=chatgpt.com#maintenance-windows

I hope this has been helpful!

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