4.0.0 HP Polyserve Matrix Server Administration Guide (T5392-96052, March 2010)

Custom device monitors
A custom device monitor is associated with a list of servers and a list of virtual hosts
configured on those servers. A custom device monitor can be active on only one
server at a time. On each server, the monitor uses a probe mechanism to determine
whether the service is active. The probe mechanism is in one of the following states
on each server: Up, Down, Unknown, Timeout.
A custom device monitor also has an activity status on each server. This status indicates
the current activity of the monitor on the server. The status can be one of the following:
Starting, Active, Suspended, Stopping, Inactive, Failure.
If it is necessary to fail over a virtual host associated with the device monitor, Matrix
Server looks for a server that meets both of these conditions: the device monitor is
active, and the device monitor probe reports an Up status. If Matrix Server cannot
locate a server where the device is active and the probe status is Up, the virtual host
will be left inactive across the cluster.
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