6.5

Table Of Contents
1Introduction
This chapter includes the following topics:
“vCenter Server Heartbeat Concepts,” on page 9
“vCenter Server Heartbeat Protection Levels,” on page 10
“vCenter Server Heartbeat Communications,” on page 13
“vCenter Server Heartbeat Switchover and Failover Processes,” on page 15
vCenter Server Heartbeat Concepts
vCenter Server Heartbeat is a Windows based service specically designed to provide high availability protection
for vCenter Server congurations without requiring any specialized hardware.
Architecture Overview
vCenter Server Heartbeat uses an Active–Passive” architecture which enables it to provide “High Availability
(HA)” in a Local Area Network (LAN) or “Disaster Recovery (DR)” in a Wide Area Network (WAN) for
vCenter Server, View Composer and SQL Server. The vCenter Server Heartbeat software is installed on an
existing production server known as the “Primary” server running the protected applications (vCenter Server,
View and SQL Server). An additional server, known as the “Secondary” server, operates as a ready standby
server to provide service in the event of an application, system, or hardware failure, or when the Administrator
needs to perform system maintenance. The terms Primary and Secondary refer to the “Identity” of each server
instance, and these identities do not change.
Active / Passive Roles
The applications protected by vCenter Server Heartbeat will run on the Active” server. Only one server can
be active at any one time and the active server will host the “Principal (Public) IP Address” which is used by
clients to access the application. The “Passive” server is only accessible on the network via its assigned
“Management IP Address”. Active and passive refer to the “Role” that the server is performing. The role can
be changed by a “Failover or when the administrator performs a “Switchover. To ensure the servers can
provide a seamless switchover / failover experience for clients, the servers need to be symmetrical. To ensure
that the Secondary server has all the programs and components installed in the same location, the install process
includes a cloning procedure. Clients will continue to connect to vCenter Server or SQL Server using the original
and unique fully qualied domain name that was used previously by clients. During installation, a service
name is congured in vCenter Server Heartbeat which will continue to resolve in DNS to the Principal (Public)
IP address regardless of which server is hosting the Principal (Public) IP address.
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