Distributed AG

going though Allan Hirt’s 24 SQLPASS  recording, he has explained the new feature of SQL Server Availability group you can get it here.


he is expert in Clustering /AG/ and published several blogs and books.

Distributed AG is advance and extended to AG its like AG to AG

one AG which will be on WSFC between two instances.


WSFC 1 :Instance A is AG with Instance B and

WSFC 2 :Instance C is AG with Instance D

so we can perform Distributed AG from Instance A to Instance C

then all four instances are in sync with each other. but it has some issues if we make it sync. so its recommendation to make WSFC 1 to WSFC 2 with async so that things will be working efficiently else Instance A will be quite slow to get sync all.

It has its limitations:

important limitation is we can configure it only with T-SQL queries. not with GUI and Powershell(this may overcome in future release)

supported in Enterprise edition only.

Automatic fail over to secondary AG is not supported for now

Thanks Allan 🙂



This entry was posted in High Avaliability, Others, sql 2016 and tagged , , , , . Bookmark the permalink.

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