Increasing Up Time

It is important to understand initially that no clustering software can increase up time. All they can do is reduce down time. Generally, there are four reasons for lack of up time:

1. Application failures: The application crashes because of bad data or other internal coding faults.
2. Server failures: The hardware hosting the application fails, often because of internal component failures, like power supplies, SCSI cards, etc.
3. controllable infrastructure failures: things like global power supply failure, Internet gateway failure.
4. uncontrollable failures: Anything else (fire, flood, earthquake).