One method of providing vCenter Server availability is to use the Watchdog feature in a vSphere HA cluster.
vSphere HA is configured by using vCenter Server at the cluster level. After it has been enabled, vSphere HA monitors hosts and virtual machines (VMs) and takes the user-configured action with or without vCenter Server availability. For more information on vSphere HA and the requirements to set up a cluster, see the vSphere Availability documentation.
Starting with vSphere 6.x, vCenter Server Heartbeat is discontinued. The Watchdog and vSphere HA option replaces this technology and provides vCenter Server availability.
If you are using vCenter Server Appliance, you must use this option instead of an MSCS cluster.
Cluster Recommendations for Protecting vCenter Server
When configuring the vSphere HA and vSphere DRS cluster that you use to provide vCenter Server availability by protecting the vCenter Server database server, observe these recommendations.
Place all database servers in a dedicated management cluster.
For vSphere DRS, create VM and host anti-affinity rules to prevent the database servers from running on the same host.
Set the ForceAffinePoweron vSphere DRS advanced option to a value of 1 to enable strict enforcement of vSphere DRS rules when servers are powered on.
Enable vSphere HA with both host and VM monitoring.
Enable and properly configure vSphere HA admission control for the cluster.
Set the VM restart priority for the VM or VMs that are hosting the vCenter Server database to High.