6.5

Table Of Contents
Upon detection of missed heartbeats vCenter Server Heartbeat performs the following steps:
1 As soon as the active server detects that the VMware Channel is experiencing missed heartbeats, it will
determine if a valid failover target (the passive server) is present.
Simultaneously, once the passive server detects missed heartbeats, it will determine if it is a valid failover
target.
2 Next, the active server will determine if it is synchronized with the failover target (the passive server). If
synchronized, it will continue to the next step. If it is not synchronized, it will veto a failover.
Simultaneously, the passive server checks to see if it is synchronized with the active server. If synchronized,
it will continue to the next step. If it is not synchronized, it will veto a failover.
3 At this point, both the active and passive servers check the congured value of the Failover timeout and
start a "Heartbeat lost" countdown. Both servers should start the countdown at approximately the same
time.
4 Failover or isolation of the active server is postponed until the congured Failover timeout value (in seconds)
has elapsed and it is during this period that both servers accomplish steps 1 & 2.
5 Once the congured Failover timeout period has elapsed, the active server assumes the VMware Channel
is lost and will attempt to ping the failover target (passive server) via the Public network. If the ping is
successful, active server isolation is vetoed. If the attempt to ping the failover target is unsuccessful, the
active server will proceed to the next step.
Simultaneously, the passive server assumes the VMware Channel is lost and attempts to ping the active
server via the Public network. If the ping is successful, failover is vetoed. If the ping attempt is unsuccessful,
the passive server proceeds to the next step.
Note If the servers have reached this point, then neither server can see the other server.
6 Both the active and passive servers will check their connectivity to the Public network. If the active server
has lost connectivity to the Public network, it will isolate itself by making itself passive (potential active).
Should the active server reconnect with the passive, it will become active again. Otherwise, it will remain
passive. If the passive server has lost connectivity to the Public network, it will veto a failover.
Configuring Response Times
vCenter Server Heartbeat also allows you to congure the time to wait following a channel connection before
starting replication and the time to wait following channel disconnection before stopping replication.
Procedure
1 Click Congure Response Times to open the Server Monitoring: Response Times dialog.
2 Type new numeric values (seconds) into the text boxes or use the arrow buttons to select new values.
3 Click OK.
34 VMware, Inc.
Administrator Guide