This MIB module describes the vCenter High Availability Service (VCHA).
A VCHA cluster consists of three VMs identified by a single instance UUID.
One is the Active vCenter VM that serves client requests. Second is the
Passive VM that is identical to the Active vCenter VM in terms of database
and filesystem state. Passive VM constantly receives updates from Active
VM and takes over the role of Active vCenter VM in the event of a
failover. Third is the Witness VM that acts as a quorum VM in a VCHA
cluster. The sole purpose of Witness VM is to avoid classic split-brain
problem in a VCHA cluster.

                        client
                           +
                           |
                           |
          +----------------v---+       +--------------------+
          |            Public IP       |                    |
          |                    |       |                    |
          |   Active vCenter   |       |  Passive vCenter   |
          |                    |       |                    |
          +---Private-IP+------+       +------+Private-IP---+
                   ^ <--------------------------> ^
                   |    DB & File replication     |
                    +                            +
                     +                          +
                      +                        +
                       +------>    <----------+
                         +----Private-IP----+
                         |                  |
                         |  Witness vCenter |
                         |     (Quorum)     |
                         |                  |
                         +------------------+

All events will not be repeated for the duration of a given state entered.

It is highly recommended that the administrator links the SNMP trap receiver
to both public network and vCenter HA cluster network, so that the
monitoring system is able to get notified as long as one of the
networks is up.