Increasing The "Uptime" Of Services

• Most of us are proud of the 'uptime' of our machines.
• Fewer of us are proud of the 'uptime' of the services our machines supply.
• Users of our services don't care for the machine's uptime - only for that of the services it runs.
• If we will use several machines to run the same service, we could achieve a better "service uptime".
• High-Availability (HA) cluster software is used to help us manage a set of services on a set of machines, and make sure that the service out-lives the non-availability of any one of these machines.
• Note: sometimes we could also increase the performance, but we will concentrate on High-Availability today.

Originally written by guy keren