3.1.2 Matrix Server Administration Guide

Chapter 11: Configure Virtual Hosts 159
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• After the virtual host fails over to node 2, a service monitor probe fails
on that node. Now both nodes have a down service monitor. Failback
does not occur because the servers are equally healthy. If the failed
service is then restored on node 1, that node will now be healthier
than node 2 and failback will occur. (Note that if the virtual host policy
was
AUTOFAILBACK, failback would occur when the probe failed on
node 2 because both servers were equally healthy.)
• After the virtual host fails over to node 2, all service monitor probes
fail on that node. Node 1, with one down monitor, is now healthier
than node 2, with three down monitors, and failback will occur.
Failback Policy and Monitor Probe Severity
The following table shows how the virtual host failback policy interacts
with the probe severity setting for service and device monitors.
Virtual Host
Policy
Monitor Probe
Severity
Behavior When Probe
Reports DOWN
AUTOFAILBACK NOFAILOVER
Failover does not occur.
AUTORECOVER
Failover occurs. When service
is restored, failback occurs.
NOAUTORECOVER
Failover occurs and the
monitor is disabled on the
original server. When the
monitor is reenabled, failback
occurs.
NOFAILBACK NOFAILOVER
Failover does not occur.
AUTORECOVER
Failover occurs. The virtual
host remains on the backup
server until a “healthier”
server is available.
NOAUTORECOVER
Failover occurs and monitor is
disabled on the original server.
The virtual host remains on
the backup server until a
“healthier” server is available.