Επεξεργασία

Κοινή χρήση μέσω


Remove an availability group (SQL Server)

Applies to: SQL Server

This article describes how to delete (drop) an Always On availability group by using SQL Server Management Studio, Transact-SQL, or PowerShell in SQL Server. If a server instance that hosts one of the availability replicas is offline when you delete an availability group, after coming online, the server instance will drop the local availability replica. Dropping an availability group deletes any associated availability group listener.

Note that, if necessary, you can drop an availability group from any Windows Server Failover Clustering (WSFC) node that possesses the correct security credentials for the availability group. This enables you to delete an availability group when none of its availability replicas remain.

Important

If possible, remove the availability group only while connected to the server instance that hosts the primary replica. When the availability group is dropped from the primary replica, changes are allowed in the former primary databases (without high availability protection). Deleting an availability group from a secondary replica leaves the primary replica in the RESTORING state, and changes are not allowed on the databases.

Limitations and Recommendations

  • When the availability group is online, deleting it from a secondary replica causes the primary replica to transition to the RESTORING state. Therefore, if possible, remove the availability group only from the server instance that hosts the primary replica.
  • If you delete an availability group from a computer that has been removed or evicted from the WSFC failover cluster, the availability group is only deleted locally.
  • Avoid dropping an availability group when the Windows Server Failover Clustering (WSFC) cluster has no quorum. If you must drop an availability group while the cluster lacks quorum, the metadata availability group that is stored in the cluster is not removed. After the cluster regains quorum, you will need to drop the availability group again to remove it from the WSFC cluster.
  • On a secondary replica, DROP AVAILABILITY GROUP should only be used only for emergency purposes. This is because dropping an availability group takes the availability group offline. If you drop the availability group from a secondary replica, the primary replica cannot determine whether the OFFLINE state occurred because of quorum loss, a forced failover, or a DROP AVAILABILITY GROUP command. The primary replica transitions to the RESTORING state to prevent a possible split-brain situation. For more information, see How It Works: DROP AVAILABILITY GROUP Behaviors (CSS SQL Server Engineers blog).

Permissions

Requires ALTER AVAILABILITY GROUP permission on the availability group, CONTROL AVAILABILITY GROUP permission, ALTER ANY AVAILABILITY GROUP permission, or CONTROL SERVER permission. To drop an availability group that is not hosted by the local server instance you need CONTROL SERVER permission or CONTROL permission on that Availability Group.

Using SQL Server Management Studio

To delete an availability group

  1. In Object Explorer, connect to the server instance that hosts primary replica, if possible, or connect to another server instance that is enabled for Always On Availability Groups on a WSFC node that possess the correct security credentials for the availability group. Expand the server tree.

  2. Expand the Always On High Availability node and the Availability Groups node.

  3. This step depends on whether you want to delete multiple availability groups or only one availability group, as follows:

  4. Right-click the selected availability group or groups, and select the Delete command.

  5. In the Remove Availability Group dialog box, to delete all the listed availability groups, click OK. If you do not want to remove all the listed availability groups, click Cancel.

Using Transact-SQL

To delete an availability group

  1. Connect to the server instance that hosts the primary replica, if possible, or connect to another server instance that is enabled for Always On Availability Groups on a WSFC node that possess the correct security credentials for the availability group.

  2. Use the DROP AVAILABILITY GROUP statement, as follows

    DROP AVAILABILITY GROUP group_name

    where group_name is the name of the availability group to be dropped.

    The following example deletes the MyAG availability group.

    DROP AVAILABILITY GROUP MyAG;  
    

Using PowerShell

To delete an availability group

In the SQL Server PowerShell provider:

  1. Change directory (cd) to the server instance that hosts the primary replica, if possible, or connect to another server instance that is enabled for Always On Availability Groups on a WSFC node that possess the correct security credentials for the availability group.

  2. Use the Remove-SqlAvailabilityGroup cmdlet.

    For example, the following command removes the availability group named MyAg. This command can be executed on any server instance that hosts an availability replica for the availability group.

    Remove-SqlAvailabilityGroup `   
    -Path SQLSERVER:\Sql\Computer\Instance\AvailabilityGroups\MyAg  
    

    Note

    To view the syntax of a cmdlet, use the Get-Help cmdlet in the SQL Server PowerShell environment. For more information, see Get Help SQL Server PowerShell.

To set up and use the SQL Server PowerShell provider

Related Content

See Also

Overview of Always On Availability Groups (SQL Server)
Creation and Configuration of Availability Groups (SQL Server)