How Notification Works

The notifier process receives notification from HAD, formats the notification, and generates an SNMP (V2) trap or sends an email to the designated recipient, or does both. If you have configured owners for resources, groups, or for the cluster, VCS also notifies owners of events affecting their resources. A resource owner is notified of resource-related events, a group owner of group-related events, and so on. See the appendix VCS Attributes for descriptions of the attributes that define owners for cluster objects.

There are four severity levels: SevereError, Error, Warning, and Information. SevereError indicates the highest severity level, Information the lowest. Note that these severity levels are case-sensitive.

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SNMP traps sent by VCS are forwarded to the SNMP console. Typically, traps are predefined for events such as service group or resource faults. You can use the hanotify utility to send additional traps.

Event Messages and Severity Levels

When the VCS engine, HAD, starts up, it is initially configured to queue all messages as Information, the lowest severity level. However, when notifier connects to VCS, the severity communicated by notifier to HAD is one of the following, depending on which is the lowest:

• lowest severity for SNMP options
• lowest severity for SMTP options

If notifier is started from the command line without specifying a severity level for the SNMP console or SMTP recipients, notifier communicates the default severity level Warning to HAD. If notifier is configured under VCS control, severity must be specified. See the description of the NotifierMngr agent in the VERITAS Cluster Server Bundled Agents Reference Guide.

For example, if the following severities are specified for notifier:

• Warning for email recipient 1
• Error for email recipient 2
• SevereError for SNMP console

Notifier communicates the minimum severity, Warning, to HAD, which then queues all messages labelled severity level Warning and greater.

Notifier ensures the recipient gets only the messages that he or she has been designated to receive (according to the specified severity level). However, until notifier communicates the specifications to HAD, HAD stores all messages, because it does not know the severity the user has specified. This prevents messages from being lost between the time HAD stores them and notifier communicates the specifications to HAD.