Typical Failover Cluster Operation

• Cluster members monitor each other’s health by heartbeating over multiple communication channels (network, serial, proprietary).

• Start cluster services when the other member is down.

• The hard part -- knowing when the other member is down. A credible commercial cluster offering must address:

  • True system failure - system died, crashed, lost power
  • Planned maintenance, clean shutdown
  • Communications partition (ie, network outage)
  • System hangs (with subsequent resurrection)

Notes: