The Sun Cluster Geographic Edition software uses heartbeats to monitor the state between partner clusters. Heartbeats are sent over the public network to detect cluster failures at geographically separated sites. Heartbeat monitoring is part of a partnership configuration. For example, a cluster failure occurs when all nodes of a cluster shut down. The Sun Cluster Geographic Edition software uses the heartbeat status to notify administrators of failures or to trigger a failover to a secondary cluster at an alternate site. Heartbeats could also be lost when a cluster loses access to the public network and no communication occurs between the partner clusters.
The heartbeat monitor uses plug-in modules to query the heartbeat status of its partners. The Sun Cluster Geographic Edition software offers default plug-ins for monitoring through a TCP/UDP connection.
You can use customize plug-ins to provide a data path over alternate communication links, such as email, HTTP, satellite, and microwave towers.