2. Heartbeat Is a daemon that provides cluster infrastructure. It must be combined with a cluster resource manager. The CRM takes care of stopping and starting services. Heartbeat is usually associated with pacemaker

3. Heartbeat The Heartbeat communication module provides strongly authenticated,locally-ordered multicast messaging. unicast UDP over IPv4; broadcast UDP over IPv4; multicast UDP over IPv4; serial link communications. Heartbeat can detect node failure in less than half a second.

4. Service Provided The heartbeat layer has an API which provides the following classes of services: intra-cluster communication - sending and receiving packets to cluster nodes configuration queries connectivity information (who can the current node hear packets from) - both for queries and state change notifications basic group membership services

5. Cluster Library Function The Cluster plumbing library is a collection of very useful functions which provide a variety of services used by many of our main components. A few of the major objects provided by this library include: memory management oriented to continuously running services Hierarchical name-value pair messaging facility promoting portability and version upgrade compatibility (also provides optional message compression facilities) Core dump management utilities - promoting capture of core dumps in a uniform way, and under all circumstances timers (like glib mainloop timers - but they work even when the time of day clock jumps) child process management - death of children causes invocation of process object, with configurable death-of-child messages Realtime management - setting and unsetting high priorities, and locked into memory attributes of processes. User id management for security purposes, for processes which need some root privileges.

6. Install Needs Two computers, hardware does not have to be the same. There must be one Primary Server(node1) and a Backup Server(node2) It is recommended that both nodes have a second NIC.

7. Installed Packages Apache FTP Samba DNS DHCP Squid

8. Works Cited http://www.linuxjournal.com/article/5862?page=0,1 http://hapm.sourceforge.net/index-en.html http://www.linux-ha.org/doc