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Version: 2023.3

Configuring the SQL Database Server Cluster (AlwaysOn)

The SQL server database clustering uses the AlwaysOn Availability Group solution.

The AlwaysOn Availability Groups feature is a high-availability and disaster-recovery solution that provides an enterprise-level alternative to database mirroring. AlwaysOn Availability Groups maximizes the availability of a set of user databases for an enterprise. An availability group supports a failover environment for a discrete set of user databases, known as availability databases that fail over together. An availability group supports a set of read-write primary databases and one to four sets of corresponding secondary databases. Optionally, secondary databases can be made available for read-only access and/or some backup operations.

An availability group fails over at the level of an availability replica. Failovers are not caused by database issues, such as, a database becoming suspect due to a loss of a data file, deletion of a database, or corruption of a transaction log. For more information about AlwaysOn Availability Groups, see https://msdn.microsoft.com/en-us/library/hh510230(v=sql.110).aspx.

Note: AlwaysOn Availability Groups is a Microsoft feature.

The supported versions of MS SQL Server are:

  • SQL Server 2012 Enterprise Edition
  • SQL Server 2014 Enterprise Edition
  • SQL Server 2016 Standard Edition

Setting up and configuring an instance of SQL Server to Support AlwaysOn Availability Groups​

For more information about AlwaysOn Availability Groups, see https://msdn.microsoft.com/en-us/library/gg509118(v=sql.110).aspx.

Prerequisite​

Set-up nodes with Windows Server Failover Clustering (WSFC)

Configuring SQL Server AlwaysOn availability group​

To configure the SQL Server AlwaysOn availability group:

  1. Open SQL Server on one of the nodes.

  2. Connect to all SQL servers that should be part of the SQL cluster.

  3. Choose View > Registered Servers.

  4. Add the required servers to a new group.

  5. Right-click on a server and click SQL Server Configuration Manager.

  6. Select SQL Server Services.

  7. Right-click the SQL Server instance and select Properties.

  8. Open the AlwaysOn High Availability tab.

  9. Check the Enable AlwaysOn Availability Groups check-box.

    Note: If there is no cluster name, make sure to install Windows failover cluster and configure a cluster first.

  10. Right-click the SQL Server instance and click Restart.

  11. Enable AlwaysOn for each of the DB cluster nodes.

  12. Repeat steps 5-10 for each SQL server presented in the MSSQL registered servers pane.

    The cluster is now configured for AlwaysOn.