exVhosts for Availability Groups with DxAdmin Quick Start Guide
This guide describes how to add an Extended Vhost (exVhost) to a DxEnterprise cluster and then add an availability group to the exVhost. DxEnterprise supports two types of Vhosts: Standard Vhosts (Vhosts), which have nodes as members, and exVhosts, whose members consist of other Vhosts. The exVhosts are designed for running an availability group (AG) across multiple HA instances. This gives users the ability to have HA on both the primary replica and secondary replicas for the AG while providing independent health monitoring and failovers of the HA instances and the AG.
This doc covers the deployment of three AG replicas. When deploying availability groups, please be aware of Quorum Considerations for SQL Server Availability Groups.
- DxEnterprise HA instances will need to be configured beforehand. For more information on configuring an HA instance, please see the Add an HA SQL Server Instance section of the DxEnterprise Admin Guide.
For SQL Server on Linux, SQL Server 2019 CU9 or later will need to be installed and virtualized.
Create the exVhost Availability Group
Add an exVhost to the cluster.
Right-click on DxCluster and select Add Virtual Host.
Add a name for the exVhost
Add the virtual IP address for the exVhost. If no virtual IP is required, then supply
*127.0.0.1to assign the local loopback address to the exVhost.
Under Member Type, select VHOST.
Add the desired Vhost members from the Available Members list to the Selected Members list.
OPTIONAL: Add a probe port for internal load balancer probing.
Add the Availability Group to the exVhost.
Right-click on the exVhost and select Add availability group.
Add a name for the availability group.
Verify that the correct instances are selected for each Vhost.
Set the desired database mirroring port (default is 5022).
Verify that the correct Availability Mode is selected for each Vhost.
OPTIONAL: Select the Tunnel checkbox to automatically create tunnel connections between AG members. This is applicable for cross-site, cross-domain cluster topology joined through the DH2i Matchmaking Service (match.dh2i.com). If the Tunnel checkbox is checked, tunnel ports are automatically assigned and visible in the UI. These automatic values can be changed if desired.
OPTIONAL: Click Authenticate to enter credentials for AG management on each replica. By default, DxEnterprise will create and manage the availability group using the same credentials as the underlying HA instance. Authenticating via different credentials on this dialog will instead use the provided credentials for AG creation and management.
Select OK to commit the changes.