- HA-aware applications
Applications that are aware of the availability of nodes and
resources. The resources can be other application components, communication
end points, processes, or groups of resources. An application that is HA-aware
is designed to recover from a failure.
- heartbeat
An IP packet that is periodically multicast through each of
the two physical interfaces of each peer node. When a heartbeat is detected
through a physical interface, it indicates that the node is reachable and
that the physical interface is alive. Heartbeats are multicast by the nhprobed daemon and detected by the nhprobed
daemon.
- highly available services
Services that run on the master node and vice-master node
only. The Reliable Boot Service and Reliable NFS are highly available services.
If the master node or one of these services on the master node fails, a failover
occurs.
See also distributed services.
- HME
An Ethernet card driver.
- horizontal scalability
The ability to add nodes to a cluster to increase the processing
capacity of the system.
- host part
The second part of an Internet address. The host part of an
IP address identifies a node on a given network.
See also netmask and network part.
- hot-swap
The removal and replacement of a hardware component or board
without shutting down the entire system.