Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Continental Cluster
Understanding Continental Cluster Concepts
Chapter 5186
How Notifications Work
A central part of the operation of ContinentalClusters is the
transmission of notifications following the detection of a cluster event.
Notifications occur at specifically coded times, and at two different
levels:
• Alert—when a cluster event should be considered noteworthy.
• Alarm—when an event shows evidence of a cluster failure.
Notifications are typically sent as:
• Email messages
• SNMP traps
• Text log files
• OPC messages to OpenView IT/Operations
In addition, notifications are sent to an event log on the system where
monitoring is taking place.
NOTE An email message can be sent to an address supplied by a pager service
that will forward the message to a specified pager system. Contact your
pager service provider for more information.
Alerts
Alerts are intended as informational. Some typical uses of alerts include:
• Notification that a cluster has been halted for a significant amount of
time.
• Notification that a cluster has come up after being down or
unreachable.
• Notification that a cluster came down for any reason.
• Notification that a cluster has been in an unreachable state for a
short period of time. An alert is sent in this case as a warning that an
alarm might be issued later if the cluster’s state remains
unreachable for a longer time.