Using EMS HA Monitors

12 Chapter 1

Installing and Using EMS

What are EMS HA Monitors?

EMS HA Monitors (Event Monitoring Service High Availability Monitors) are a set

of monitors and a monitoring service that polls a local system or application

resource and sends messages when events occur. An event can simply be deﬁned as

something you want to know about. For example, you may want to be alerted when

a disk fails or when available ﬁlesystem space falls below a certain level. EMS

allows you to conﬁgure what you consider an event for any monitored system

resource.

The advantage EMS has over built-in monitors is that requests can be made to send

events to a wide variety of software using multiple protocols (opcmsg, SNMP, TCP,

UDP). For example, you can conﬁgure EMS so that when a disk fails a message is

sent to MC/ServiceGuard and IT/Operations. These applications can then use that

message to trigger package failover and to send a message to an administrator to ﬁx

the disk.

EMS HA Monitors consist of a framework, a collection of monitors, and a

conﬁguration interface that runs under SAM (System Administration Manager). The

framework starts and stops the monitors, stores information used by the monitors,

and directs monitors where to send events. A standard API provides a way to add

new monitors as they become available, or to write your own monitors; see the

document Writing Monitors for the Event Monitoring Service (EMS) available from

the high availability web site: http://www.hp.com/go/ha

Figure 1-1 Event Monitoring Services High Availability Monitors

Target, such as

IT/Operations,

MC/ServiceGuard

Registrar

Framework

System and

application

MONITORS

API

Resource

dictionary

Client, such as

SAM interface to EMS,

MC/ServiceGuard package configuration

resources