Managing Serviceguard Fifteenth Edition, reprinted May 2008

Understanding Serviceguard Software Components
How the Package Manager Works
Chapter 384
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, refer to the man
page for resls(1m).
Using the EMS HA Monitors
The EMS (Event Monitoring Service) HA Monitors, available as a
separate product (B5736DA), 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