Can a SQL Server Distributed Availability Group have multiple secondary replica Availability Groups?

Question

I have a question regarding the configuration of SQL Server Distributed Availability Groups (DAGs). I understand that a DAG is used to replicate data from one Availability Group (AG) to another. However, I'm curious about the possibility of having multiple secondary replica AGs for a single DAG.

Specifically, let's say I have a Distributed Availability Group named "dag1". Is it possible for "dag1" to replicate data from a primary Availability Group "ag1" to multiple secondary Availability Groups, such as "ag2" and "ag3"?

In other words, can a single DAG have a one-to-many relationship with secondary replica AGs?

I would greatly appreciate if someone could clarify whether this configuration is supported and provide any additional insights or considerations when setting up a DAG with multiple secondary replica AGs.

Thank you in advance for your help!

Answer 1

In other words, can a single DAG have a one-to-many relationship with secondary replica AGs?

No, it cannot. Availability Groups, however, can be part of multiple Distributed Availability Groups. the inability to have multiple Availability Groups in a Distributed Availability Group is somewhat called out in the documentation, though it could be changed to be more explicit.

If you want to have multiple Availability Groups in a Distributed Availability Group, you'll need to choose a hub and spoke model or a daisy chain model. Both are described in the documentation linked above.