sys.dm_hadr_cluster (Transact-SQL)
Applies to: 
SQL Server
If the Windows Server Failover Clustering (WSFC) node that hosts an instance of SQL Server that is enabled for Always On availability groups has WSFC quorum, sys.dm_hadr_cluster returns a row that exposes the cluster name and information about the quorum. If the WSFC node has no quorum, no row is returned.
Tip
Beginning in SQL Server 2014 (12.x), this dynamic management view supports failover cluster instances (FCIs) in addition to availability groups (AGs).
| Column name | Data type | Description |
|---|---|---|
cluster_name |
nvarchar(128) | Name of the WSFC cluster that hosts the instances of SQL Server that are enabled for Always On availability groups. |
quorum_type |
tinyint | Type of quorum used by this WSFC cluster, one of: 0 = Node Majority. This quorum configuration can sustain failures of half the nodes (rounding up) minus one. For example, on a seven node cluster, this quorum configuration can sustain three node failures. 1 = Node and Disk Majority. If the disk witness remains on line, this quorum configuration can sustain failures of half the nodes (rounding up). For example, a six node cluster in which the disk witness is online could sustain three node failures. If the disk witness goes offline or fails, this quorum configuration can sustain failures of half the nodes (rounding up) minus one. For example, a six node cluster with a failed disk witness could sustain two (3-1=2) node failures. 2 = Node and File Share Majority. This quorum configuration works in a similar way to Node and Disk Majority, but uses a file-share witness instead of a disk witness. 3 = No Majority: Disk Only. If the quorum disk is online, this quorum configuration can sustain failures of all nodes except one. 4 = Unknown Quorum. Unknown Quorum for the cluster. 5 = Cloud Witness. Cluster utilizes Microsoft Azure for quorum arbitration. If the cloud witness is available, the cluster can sustain the failure of half the nodes (rounding up). |
quorum_type_desc |
varchar(50) | Description of quorum_type, one of:NODE_MAJORITY NODE_AND_DISK_MAJORITY NODE_AND_FILE_SHARE_MAJORITY NO_MAJORITY:_DISK_ONLY UNKNOWN_QUORUM CLOUD_WITNESS |
quorum_state |
tinyint | State of the WSFC quorum, one of: 0 = Unknown quorum state 1 = Normal quorum 2 = Forced quorum |
quorum_state_desc |
varchar(50) | Description of quorum_state, one of:UNKNOWN_QUORUM_STATE NORMAL_QUORUM FORCED_QUORUM |
Remarks
In a Windows Server Failover Cluster (WSFC), the cluster columns display the Windows cluster details. In cases where there's no Windows cluster, such as read-scale availability groups, or availability groups on Linux, columns related to the cluster might display data about an internal default cluster. These columns are for internal use only and can be disregarded.
Permissions
For SQL Server 2019 (15.x) and previous versions, requires VIEW SERVER STATE permission on the server.
For SQL Server 2022 (16.x) and later versions, requires VIEW SERVER PERFORMANCE STATE permission on the server.