As we know Microsoft Azure has something like 55 regions currently available. One question that I see come up a lot is, about region placement of resource groups as well as resources. This usually boils down to if a have a resource group that has a region of X, can I put resources within that resource group in region Y? X and Y really don’t matter here, as long as they are different.
The short answer here is yes. The why becomes a little more interesting. The region that resources are configured it is pretty self-explanatory, those resources run in that region. Let’s assume an Azure SQL DB Server that is put in the West US region. That means that the database server will be physically located within the West US region. The public IP Address for that Azure SQL DB server will be hosted in WestUS , the storage for it will be in US West.
When it comes to the location of a resource group, that is simply the location that holds the information about the resource group. This means that you can put a resource group is any region, and you can put resources from any region within this resource group.
The only time that you’ll really care about putting an Azure Resource Group is a different region is if that region has an outage. This will cause you to not be able to create new resources within the resource group until the region comes back online. If the region hosting the resource group goes offline, this will not cause the resources within that resource group to go offline. The only impact that you’ll notice is that you can’t create resources within that resource group (you might also have weird issues starting and stopping resources within that resource group).
Let’s think about our example again. We have a SQL Server in West US and we put that in a resource group that is created is Central US. If Central US goes offline, then the SQL Server in West US stays online. If we wanted to create a new Azure SQL DB Server in the resource group, we won’t be able to. The Azure SQL DB Server would need to be created in a new resource group and when Central US is back online the Azure SQL DB Server that is new could be moved into the Resource Group within Central US.
Hopefully, this helps dispel some of the myths of regions and resource placement.