Clustering technologies have been in existence for many years. It is a mature technology that is now becoming more cost-effective, and it is being implemented on a wide range of servers across multiple operating systems. Downtime is costly. Even planned downtime, for maintenance or expansion, potentially makes a business unavailable somewhere in the world. With competitors just a mouse-click away, customers can simply go elsewhere if the system doesn't respond.
Many businesses now consider generic applications as business-critical.
This means only 26 and one half minutes of downtime per year are possible. Both single and multi-processor configurations are supported. Many mixed server combinations could be supported. At the present time only like server combinations are being supported. If a business case warrants, mixed servers will be considered.