4.1.0 HP PolyServe Matrix Server administration guide (T5392-96073, October 2010)

After creating virtual hosts, you will need to configure your network applications to
recognize them. When clients want to access a network application, they use the
virtual host address instead of the address of the server where the application is
running.
Service and device monitors
A service is a network service such as HTTP or FTP that is installed and configured
on the servers in the cluster. Matrix Server can be configured to watch specific services
with service monitors.
A service monitor is created on a virtual host. The service being monitored should
be installed on all servers associated with that virtual host. When a service monitor
determines that a service has failed, Matrix Server transfers the virtual host for that
service to a backup server. For example, if the HTTP service fails, Matrix Server will
transfer the HTTP traffic to a backup server that provides HTTP.
Matrix Server includes several built-in service monitors for monitoring well-known
network services. You can also configure custom monitors for other services.
A device monitor is similar to a service monitor; however, it is assigned to one or
more servers. Matrix Server provides several built-in device monitors. The DISK device
monitor can be used to watch local disk drives or to check access to a partition on
a SAN disk. The GATEWAY device monitor watches gateway devices. You can also
define your own custom device monitors.
By default, when a device monitor is assigned to a server, all virtual hosts on that
server are dependent on the device monitor. However, you can select the virtual
hosts that will be dependent on the device monitor. If a device monitor indicates that
a device is not functioning properly on the primary server, Matrix Server transfers
the dependent virtual host addresses from the primary server to a backup server.
Event notifier services
Matrix Server provides event notifier services that can be configured to respond when
certain matrix events occur. The services can send an SNMP trap to an SNMP trap
forwarding target, send email to certain addresses, or run a script. Each service can
be configured with the specific events that should trigger a response from the service.
Introduction to Matrix Server24