vSphere 6.5 GA became available yesterday , and you can visit William Lam amazing content for accessing all the required documents and download files for the same.
One of prime features of this new release is vCenter appliance inbuilt HA feature.
A vCenter HA cluster will consist of three vCenter server appliance instances. The first instance initially deployed as Active node, and then once HA is enabled a clone is done twice for passive and witness node. All these 3 VMs together form the HA architecture for vCenter.
When vCenter HA configuration is complete, only the Active node has an active management interface (public IP). The three nodes communicate over a private network called vCenter HA network that is set up as part of configuration. The Active node and the Passive node are continuously replicating data.
New release , new stuff !!