When low-cost Mac Mini servers began replacing Xserves (remember those?) a movement began to bring redundant server functionality into the mix. The RAIS (Redundant Array of Inexpensive Servers) project was designed to address this need. Championed by one of the first Managed Service Providers in the Mac industry, Alex Narvey of Precursor.ca.
Watchman Monitoring provides RAIS operators with early notification of issues which may lead to failover, allowing time for preventative action. In the event of auto-failover (via smart PDU devices) Watchman Monitoring will automatically warn that the system has booted off the secondary server. The RAIS can continue serving data while the primary Mini is repaired and prepped to be the next backup server.