heartbeat is a basic high-availability subsystem.  It will run
scripts at initialization, and when machines go up or down.  This
version will also perform IP address takeover using gratuitous ARPs.

It implements the following kinds of heartbeats:
        - Bidirectional Serial Rings ("raw" serial ports)
        - UDP/IP broadcast (ethernet, etc)
        - Unicast heartbeats
        - "ping" heartbeats (for routers, switches, etc.)
           (to be used for breaking ties in 2-node systems)

ldirectord is a stand-alone daemon to monitor services.

The STONITH module (a.k.a. STOMITH) provides an extensible interface
for remotely powering down a node in the cluster.

PILS is an generalized and portable open source Plugin and Interface
Loading System.  PILS manages both plugins (loadable objects), and
the interfaces these plugins implement.  PILS is designed to support
any number of plugins implementing any number of interfaces.

WWW: http://linux-ha.org/
