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Table Of Contents
Figure 1- 2. vCenter Server Heartbeat Initiated Failover
An auto-failover occurs when the passive node detects that the active node is no longer responding.This can
occur when the active node operating system crashes, loses its network connections, host hardware fails, or
otherwise becomes unavailable. The failover process is discussed in detail later in this guide.
Network Protection
vCenter Server Heartbeat proactively monitors the network by polling up to three predefined IP addresses to
ensure that the active node is visible on the network. vCenter Server Heartbeat polls by default the Primary
DNS server, the Default Gateway, and the Global Catalog server at regular intervals. If all three nodes fail to
respond, for example in the case of a network card or switch failure, vCenter Server Heartbeat can initiate a
failover, allowing the Secondary node to assume the active role and service clients.
Application Protection
vCenter Server Heartbeat running on the active node locally monitors vCenter Server and its services to verify
that vCenter Server is operational and not in an unresponsive or stopped state. This level of monitoring is
fundamental in ensuring that vCenter Server remains available to users.
If vCenter Server should fail, vCenter Server Heartbeat first attempts to restart the application on the active
node (1) in Figure 1-3.
If the application does not successfully restart, vCenter Server Heartbeat initiates an auto-failover (2) in Figure
1-3. Refer to vCenter Server Heartbeat Failover Processes, on page 14 for further information about the
failover process.
10 VMware, Inc.
vCenter Server Heartbeat Administrator's Guide