sys.dm_hadr_ag_threads (Transact-SQL)

The HADR thread telemetry DMVs (sys.dm_hadr_ag_threads and sys.dm_hadr_db_threads) allow users to quickly gain insight into thread usage by availability group and by high availability database. Understanding this thread usage is an important benchmark for tuning availability groups.

This DMV reports on thread usage at the availability group level.

Column name	Data type	Description
group_id	uniqueidentifier	Identifier of the availability group.
name	nvarchar(128)	Name of the availability group.
num_databases	int	Number of databases in the availability group.
num_capture_threads	int	Number of log capture threads used by all databases in this availability group.
num_redo_threads	int	Number of redo threads used by all databases in this availability group.
num_parallel_redo_threads	int	Number of parallel redo threads used by all databases in this availability group.
num_hadr_threads	int	Number of all always on threads used by all databases in this availability group.

Permissions

Requires VIEW SERVER STATE permission on the server.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.

See also

Always On Availability Groups Dynamic Management Views and Functions (Transact-SQL)
Always On Availability Groups Catalog Views (Transact-SQL)
Monitor Availability Groups (Transact-SQL)
Always On Availability Groups (SQL Server)