Specifications

Reference Guide
12 VMware, Inc.
The vCenter Server Heartbeat software is symmetrical in almost all respects, and either the Primary Server or
the Secondary server can take the active role and provide the protected application to the user.
Server Protection
vCenter Server Heartbeat maintains availability through operating system and hardware failure events. Two
instances of vCenter Server Heartbeat monitor each other by sending “I’m alive” messages and reciprocating
with acknowledgments over a network connection termed the VMware Channel. If the passive server detects
that this process or heartbeat has failed, a failover is initiated as illustrated in Figure 1-1.
Figure 1-1. Failover
A failover is similar to a switchover but is used in more drastic situations. A failover happens when the passive
server detects that the active server is no longer responding. This can occur when the active server hardware
crashes or loses its network connections. Rather than the active server gracefully closing, the passive server
determines that the active server has failed and requires no further operations. During failover, the passive
server immediately takes on the active server role. The mechanics of failovers are discussed later in this guide.
Network Protection
vCenter Server Heartbeat proactively monitors the capability of the active server to communicate with the rest
of the network by polling defined nodes around the network, including by default the default gateway, the
primary DNS server, and the Global Catalog server at regular intervals. If all three nodes fail to respond, for
example, due to a network card failure or a local switch failure, vCenter Server Heartbeat can initiate a
switchover, allowing the Secondary server to assume an identical network identity as the Primary server.
Application Protection
vCenter Server Heartbeat running locally on the active server monitors the protected applications and services
through the use of plug-ins. vCenter Server Heartbeat protects the following components:
 VirtualCenter Server Versions 2.5
 VMware VirtualCenter Server
 VMware Capacity Planner
 VMware Converter Enterprise
 VMware Update Manager
 VMware License Server
 vCenter Server Version 4.0
 VMware vCenter Server
 VMware Guided Consolidation Service