Alarms and Rules

An alarm is a notification of an abnormal event. Sun Management Center software enables you to monitor your system using alarms that have differing severities. The thresholds that generate these alarms are defined in the modules. The software enables you to set the thresholds that trigger simple alarms.

For example, one of the properties of the Kernel Reader module is the number of user sessions. The software enables you to set a threshold number of user sessions that, when exceeded, generates an alarm. For example, you might tell Sun Management Center software to generate a critical alarm when there are seven or more user sessions. Similarly, you might tell the software to generate a cautionary alarm when there are five or six user sessions.

The software is configured with default alarm conditions. You can set and define your own alarm thresholds for simple alarms, such as those alarms that are based on the simple rCompare (comparison) rule.

Complex rules also generate alarms. For example, one complex rule generates an alert alarm when a disk is more than 75 percent busy, the average queue length is over 10 entries, and the wait queue is increasing. This rule combines three conditions:

• Percentage of the disk that is busy

• Average queue length

• Wait queue

Unlike simple rules, these complex rules are predefined. You cannot modify complex rules. Consequently, you cannot set thresholds for complex alarms.

When an alarm is generated, the software notifies you through the main console window, and through an alarm action. The alarm action can include a message sent to a specified email address or activation of a script. You can also write a customized program that notifies you in other ways that an alarm condition has occurred.

For more information about alarms, see Chapter 12, Managing Alarms. For more information about rules, see Appendix D, Sun Management Center Software Rules.