6.3

VMware, Inc. 11
Chapter 1 Introduction
addresses for the Primary and Secondary servers separate from the shared Public (Principal) IP address.
Clients connect to vCenter Server using a unique virtual service name configured in vCenter Server Heartbeat
that resolves to the Public (Principal) IP address. When started, vCenter Server Heartbeat provides the passive
server its unique Management IP address and provides the active server with the shared Principal (Public) IP
address.
When a switchover occurs, vCenter Server Heartbeat removes the shared Principal (Public) IP address from
the currently active server and replaces it with its unique Management IP address. On the currently passive
server, vCenter Server Heartbeat removes the Management IP address and replaces it with the shared
Principal (Public) IP address thereby allowing the servers to switch roles.
Advantages of Non-Identical Nodes Configuration
Deployment of non-identical nodes allows for easy access to the passive (hidden/ready standby) server at any
time regardless of which server is active and servicing clients. Additionally, this configuration allows the
passive server to be easily accessed for maintenance purposes, updating anti-virus definition files, receiving
operating system hot-fixes, updates and patches from third-party management software, and allows use of
third-party monitoring tools.
Protection Levels
vCenter Server Heartbeat provides the following protection levels:
 Server Protection – vCenter Server Heartbeat provides continuous availability to end users through a
hardware failure scenario or operating system crash. Additionally, vCenter Server Heartbeat protects the
network identity of the production server, ensuring users are provided with a replica server on the failure
of the production server.
 Network Protection – vCenter Server Heartbeat proactively monitors the network by polling up to three
nodes to ensure that the active server is visible on the network.
 Application Protection – vCenter Server Heartbeat maintains the application environment ensuring that
applications and services stay alive on the network.
 Performance Protection – vCenter Server Heartbeat proactively monitors system performance attributes
to ensure that the system administrator is notified of problems and can take pre-emptive action to prevent
an outage.
 Data Protection – vCenter Server Heartbeat intercepts all data written by users and applications, and
maintains a copy of this data on the passive server that can be used in the event of a failure.
vCenter Server Heartbeat provides all five protection levels continuously, ensuring all facets of the user
environment are maintained at all times, and that the network (Principal (Public) network) continues to
operate through as many failure scenarios as possible.
Server Protection
vCenter Server Heartbeat provides continuous availability to end users through a hardware failure scenario
or operating system crash. Additionally, vCenter Server Heartbeat protects the network identity of the
production server, ensuring users are provided with a replica server including server name (single identity
only) and IP address on the failure of the production server.
Two instances of vCenter Server Heartbeat regularly send “I’m alive” messages and message
acknowledgments to one another over a network connection referred to as the VMware Channel to detect
interruptions in responsiveness. If the passive server detects that this monitoring process (referred to as the
heartbeat) has failed, it initiates a failover as illustrated in Figure 1-1.