SQL Clone
SQLServerCentral is supported by Redgate
Log in  ::  Register  ::  Not logged in

Where Is My Primary Replica Again?

We have many clients with multi-node Availability Groups - that is, AGs with more than two replicas.  One of the problems I have always had with Availability Group management via the GUI (admit it, you use the GUI sometimes all you non-PowerShell geeks) is the fact that most of the work needs to be done from the primary replica.  You can connect to the Availability Group manager on a secondary replica, but you can only see limited data about that particular secondary replica and can't see much about the other replicas, including *which* replica is the current primary replica!

To perform management you almost always need to connect to the primary replica, but how can I figure out which one is primary without just connecting to the instances one by one until I get lucky?

Enter the T-SQL:
AG.name AS AvailabilityGroupName
, HAGS.primary_replica AS PrimaryReplicaName
, HARS.role_desc as LocalReplicaRoleDesc
, DRCS.database_name AS DatabaseName
, HDRS.synchronization_state_desc as SynchronizationStateDesc
, HDRS.is_suspended AS IsSuspended
, DRCS.is_database_joined AS IsJoined
FROM master.sys.availability_groups AS AG
LEFT OUTER JOIN master.sys.dm_hadr_availability_group_states as HAGS
ON AG.group_id = HAGS.group_id
INNER JOIN master.sys.availability_replicas AS AR
ON AG.group_id = AR.group_id
INNER JOIN master.sys.dm_hadr_availability_replica_states AS HARS
ON AR.replica_id = HARS.replica_id AND HARS.is_local = 1
INNER JOIN master.sys.dm_hadr_database_replica_cluster_states AS DRCS
ON HARS.replica_id = DRCS.replica_id
LEFT OUTER JOIN master.sys.dm_hadr_database_replica_states AS HDRS
ON DRCS.replica_id = HDRS.replica_id
AND DRCS.group_database_id = HDRS.group_database_id
ORDER BY AG.name, DRCS.database_name
This query can be run on any of the replicas, and it will return information about the Availability Groups and their member databases, *including* the name of the primary replica instance!

Hope this helps!

Nebraska SQL from @DBA_ANDY

I’m a forty-something Microsoft SQL Server DBA of 15+ years, a devoted husband, and a father of three young boys. I have been a DBA at a public university, at a major bank, at a healthcare system, and I now work as a remote DBA with customers across the United States. I write and speak primarily about the tips and tricks that I discover along my SQL Server journey.


Leave a comment on the original post [nebraskasql.blogspot.com, opens in a new window]

Loading comments...