Managing Serviceguard Eighteenth Edition, September 2010

Using the Event Monitoring Service
Basic package resources include cluster nodes, LAN interfaces, and services, which are
the individual processes within an application. All of these are monitored by
Serviceguard directly. In addition, you can use the Event Monitoring Service registry
through which add-on monitors can be configured. This registry allows other software
components to supply monitoring of their resources for Serviceguard. Monitors currently
supplied with other software products include EMS (Event Monitoring Service) High
Availability Monitors, and an ATM monitor.
If a monitored resource is configured in a package, the package manager calls the
resource registrar to launch an external monitor for the resource. Resources can be
configured to start up either at the time the node enters the cluster or at the end of
package startup. The monitor then sends messages back to Serviceguard, which checks
to see whether the resource is available before starting the package. In addition, the
package manager can fail the package to another node or take other action if the resource
becomes unavailable after the package starts.
You can specify a monitored resource for a package in Serviceguard Manager, or on
the HP-UX command line by using the command /opt/resmon/bin/resls. For
additional information, see the manpage for resls(1m).
Using the EMS HA Monitors
The EMS (Event Monitoring Service) HA Monitors, available as a separate product,
can be used to set up monitoring of disks and other resources as package resource
dependencies. Examples of resource attributes that can be monitored using EMS include
the following:
• Logical volume status
• Physical volume status
• System load
• Number of users
• File system utilization
• LAN health
Once a monitor is configured as a package resource dependency, the monitor will notify
the package manager if an event occurs showing that a resource is down. The package
may then be failed over to an adoptive node.
The EMS HA Monitors can also be used to report monitored events to a target
application for graphical display or for operator notification. For more information,
see the latest Event Monitoring Service release notes and other documents at
www.hp.com/go/hpux-ha-monitoring-docs.
See also “Using EMS to Monitor Volume Groups” (page 132).
How the Package Manager Works 79